text:
Justia Patents US Patent for GPS/IRS global position determination method and apparatus with integrity loss provisions Patent (Patent # 5,923,286)
GPS/IRS global position determination method and apparatus with integrity loss provisions
Oct 23, 1996 - Honeywell Inc.
A system for use with an inertial reference system and a global position receiver for calculating a position error after a loss of integrity by utilizing the global position system values for position and velocity at a time just before the loss of integrity and by utilizing the inertial reference system position modified by the known error in inertial reference system position as it varies with time and the position error as calculated by the global position system velocity extrapolated over the time since integrity loss.
Latest Honeywell Inc. Patents:
Multi tier wireless communication system
Method and system for transmitting periodic and aperiodic data over a critical avionics databus
Process variable gauge interface and methods regarding same
Display screen and method of manufacture therefor
Cursor control console with rotary knob and method of use
The present invention pertains to a system employed for determining the global position of a mobile unit by employment of both an inertial reference system (IRS) and a satellite positioning system (GPS), and more specifically, a system which employs a provision for determining the mobile unit's global position and corresponding integrity during those periods of time in which the GPS satellite constellation is insufficient for establishing GPS integrity limit values by employment of RAIM.
Satellite positioning systems are now well-known in the art. Such systems, for example, NAVSTAR-GPS, are rapidly being employed for a determination of the geocentric position of mobile units, such as water and land vehicles, space and aircraft, and survey equipment, to name a few.
In aircraft, GPS systems are being utilized for navigation, flight control, and airspace control. These GPS systems may operate independently or in combination with inertial reference systems or attitude heading reference systems in order to provide information particularly during a flight mission.
Global positioning systems, hereinafter referred to as "GPS", similar to NAVSTAR, commonly use a GPS receiver, located on a mobile unit, for receiving satellite information signals transmitted from a plurality of satellites. Each GPS satellite transmits a satellite information signal containing data that allows a user to determine the range or distance between selected GPS satellites and the antenna associated with the mobile unit's GPS receiver. These distances are then used to compute the geocentric position coordinates of the receiver unit using known triangulation techniques. The computed geocentric position coordinates may, in turn, be translated to earth latitude and longitude coordinates.
In order to determine the position of the GPS receiver, a minimum of four unique satellite information signals are required, rather than the expected three (three position, unknown coordinates). This is so, since the GPS receiver generally includes a receiver clock which is not as accurate as the atomic clock normally associated with each of the satellites. Therefore, receiving satellite information signals from four different satellites provides a complete solution which permits the correction of any receiver clock error as is well-understood in the art. Herein, the GPS receiver position derived by the triangulation technique using data from multiple satellites is referred to as the "GPS estimated position", identified as POS.sub.-- GPS. The accuracy of this estimated GPS position is dependent upon many factors, including, among others, atmospheric conditions, selective satellite availability, and the relevant position of the satellites with respect to the line of sight view of the satellites.
Associated with a GPS estimated position is a "position error bound" as particularly defined by accepted GPS systems standards which have been developed by the Radio Technical Commission for Aeronautics (RTCA), in association with aeronautical organizations of the United States from both government and industry. The RTCA has defined the phrase "GPS system integrity" as the ability of a GPS system to provide timely warnings to users when the GPS system should not be used for navigation. "System integrity" is particularly identified in a document entitled "Minimum Operational Performance Standards for Airborne Supplemental Navigation Equipment Using Global Positioning System (GPS)", document number RTCA/DO-208, July 1991, prepared by: SC-159, beginning at section 1.5. As described therein, GPS is complicated in that it is a four-dimensional system involving three components of position and one time component. As also described in the aforesaid RTCA publication, the signal-in-space error transforms into a horizontal position error via a relatively complex function of a satellite constellation geometry at any given moment. The GPS integrity system must interpret the information it has about the received GPS signals and error terms in terms of the induced horizontal position error, commonly referred to as the "position error bound", and then make a decision as to whether the position error bound is outside the allowable radial error, specified for a particular phase of the flight mission in progress. The allowable error is referred to as the "alarm limit", herein referred to as the "integrity alarm limit". If the horizontal position error bound is found to exceed the integrity alarm limit, a timely warning must be issued by the GPS receiver or subsystem to notify the pilot that the GPS estimated position should not be relied upon.
Two rather distinct methods of assuring GPS integrity have evolved as civilian use of GPS has progressed. One is the Receiver Autonomous Integrity Monitoring (RAIM) concept, and the other is the ground monitoring approach that goes under the "GPS Integrity Channel" (GIC). The intent of both of these methods is the calculation of the position error bound with regard to the current GPS estimated position so that it may be compared with the alarm limit associated with a particular phase of a flight mission.
The receiver autonomous integrity monitoring system (RAIM) employs a self-consistency check among the measurements, more specifically, GPS pseudo range measurements. Satellite redundancy is required to perform a self-consistency check on an instantaneous basis. Thus, five satellites must be in view, i.e., five satellite information signals received and pseudo range measurements calculated by a GPS receiver. If fewer than five satellites are in view, the value of the predicted position error bound will be infinite. Also, constraints are placed on the satellite constellation geometry that must be met if the self-consistency check is to be effective in the presence of noise, e.g., azimuth angle of the satellite relative to user position. Generally, a satellite constellation with many satellites in view permits a robust integrity monitoring system. Conversely, a satellite constellation having only a few satellites in view, may limit the availability of an integrity monitoring system. Thus, there may be short periods when a good consistency check is not possible (less than five satellites in view). The main feature of RAIM is that it is completely self-contained and relatively easy to implement in software.
Examples of RAIM may be found in the aforementioned RTCA publication, Appendix F, and also in an article entitled "Implementation of a RAIM Monitor and a GPS Receiver and an Integrated GPS/IRS" by Mats Brenner, located at page 397, in the proceedings of ION GPS-90, Third International Technical Meeting of the Satellite Division of the Institute of Navigation, Sep. 19-21, 1990.
GPS systems which incorporate RAIM output a position error bound value which represents the probabilistic radial errors of the navigation solution, namely, the GPS estimated position of the receiver unit. Currently, RAIM may generate several numbers, including, a horizontal position error bound value (sometimes referred to as HIL--Horizontal Integrity Limit), a vertical position error bound value (sometimes referred to as VIL--Vertical Integrity Limit), and spherical position error bound for the current time, i.e., the instance of time that GPS measurements occurred.
Once calculated, the position error bound value(s), HIL and/or VIL, may be compared with selectable integrity alarm limit values to determine if the pilot can rely on the derived GPS estimated position for the current phase of the light mission. It should be recognized that some interpretation may be required dependent upon the GPS receiver's ability to simultaneously receive a plurality of satellite information signals as is well-understood in the art. However, advancements in the art of 12-channel GPS receivers have made it no longer necessary to rely on interpolation of data as before.
The allowable integrity alarm limit values may change depending upon the phase of the flight mission. For instance, if a pilot is flying in the terminal phase, the integrity alarm limit may be less stringent than if the pilot is in the approach phase of the flight mission. If the pilot is to transition from the terminal phase to the approach phase, the pilot needs to know whether the current position error bound is sufficient to allow the pilot to rely upon the GPS solution to make the transition.
As is well understood in the art, inertial reference systems employ a plurality of inertial sensors, for example, gyroscopes and accelerometers, for determining an IRS estimated position of the aircraft, hereinafter referred to as "POS.sub.-- IRS". Generally, the IRS estimated position is in terms of latitude and longitude (altitude being separately determined by other means such as an altimeter of some type). However, inherent in such inertial sensors are particular bias and drift terms which affect the accuracy of the IRS estimated position of the aircraft utilizing solely an inertial reference system. Since high inertial grade sensors, i.e., low bias and drift characteristics, are very costly, it is desirable to minimize the cost of the IRS system by using lower grade inertial sensors.
In the art, a compromise has been reached by using lower grade inertial reference systems in combination with a global positioning system to produce a high quality--lower cost navigation and flight control system. This is sometimes referred to as a Hybrid INS/GPS or IRS/GPS Inertial Reference System. These systems achieve excellent results since low grade inertial reference systems produce very accurate dynamic response characteristics, whereas, GPS provides very accurate static position information, but less accurate dynamic response information. Combining both the IRS estimated position and inertial reference information with GPS estimated position information provides excellent user position information for flight navigation and flight control applications. Accordingly, a flight management system (FMS), combines the excellent features of both the IRS and the GPS systems to provide position and inertial reference information which permits excellent flight management, flight control and navigation.
An example of a hybrid IRS/GPS system is Honeywell Inc.'s "Global Positioning Inertial Reference Unit (GPIRU) identified as an HG 1050 AG01 which is referred to as a "hybrid" system since it provides position and inertial information which are a resultant combination of GPS and inertial reference system information. The GPIRU includes an inertial reference unit with gyros and accelerometers to provide information about aircraft attitude and rate of change of position as well as providing a first source of position information. The GPIRU also receives inputs from a Global Position System Receiver to provide a second and independent source of information about the aircraft position. The two sets of information are mathematically combined in a Flight Management System (FMS) to determine a hybrid position POS.sub.-- HYB. In turn, this position value along with attitude and rate signals from the Inertial Reference Unit may be provided in a flight control for controlling aircraft.
A problem, however, with flight management systems employing GPS and IRS is the questionable integrity of the GPS estimated position information during those times in which RAIM integrity limit values are no longer available, i.e. insufficient satellite information to provide useful integrity position error bound values.
BRIEF DESCRIPTION OF THE INVENTION
The present invention uses the FMS to calculate a poisition error at anytime, t, after the loss of integrity at time, T.sub.L, by utilizing the GPS values for position and velocity at time T.sub.L just before loss of integrity and by utilizing the IRS position modified by the known error in IRS position as it varies with time and the position error as calculated by the GPS velocity extrapolated over the time (t-T.sub.L).
FIG. 1 is a combined inertial reference system and a satellite positioning system known in the prior art.
FIG. 2 is a combined inertial reference system and satellite positioning system in accordance with the present invention.
FIG. 3 is a block diagram illustrating a second order filter.
Illustrated in FIG. 1 is a simplified block diagram of a mobile unit, a hybrid IRS/GPS estimator commonly employed on aircraft. A position estimator 110, for example, as part of a flight management system as described earlier, receives as inputs (i) GPS output information identified as DATA.sub.-- GPS, further identified by numeral 122, from a satellite positioning system receiver 120, and (ii) an inertial reference output information indicated by DATA.sub.-- IRS, further identified by numeral 132 from inertial reference system 130. Position estimator 110 processes DATA.sub.-- IRS and DATA.sub.-- GPS to derive (i) a hybrid position estimate identified as POS.sub.-- HYB, and position error estimates identified as POS.sub.-- X.sub.-- ERR and POS.sub.-- Y.sub.-- ERR. This information, which will be described in detail below, is provided on output signal lines 112, 114, and 116 respectively.
As is well-understood in the art, satellite positioning system receiver 120 includes a satellite signal receiver portion 124 for receiving satellite information signals from a plurality of satellite vehicles, for example, SV1 and SV2, which form, in part, a constellation of satellite vehicles. One example, already indicated, is the NAVSTAR GPS constellation of satellites. In turn, the satellite information signals are operated on by GPS position/solution information processor 126 for providing a GPS solution information identified as DATA.sub.-- GPS on signal line 122. This information is provided as an input to position estimator 110, to a GPS integrity validation means 170 and to a GPS RAIM processor 150 on common signal line 122.
Inertial reference system 130 includes a plurality of inertial sensors indicated by block 131 as inputs to an IRS position/inertial information processor 134 for providing IRS derived position and inertial information on signal line 132, designated DATA.sub.-- IRS. This information is provided as an input to position estimator 110.
Position estimator 110, which forms in part a flight management system known in the art, utilizes the GPS solution information, DATA.sub.-- GPS, as a continuous reference for enhancing the accuracy of the IRS position/inertial information DATA.sub.-- IRS, particularly for minimizing resultant bias terms which are inherent in the inertial sensors 131. Position estimator 110 may also include an input for receiving radio position information indicated by numeral 118, e.g. VOR signal information designated as DATA.sub.-- RADIO.
Position estimator 110 provides as an output on signal line 112 an estimated position identified as POS.sub.-- HYB. The output POS.sub.-- HYB of position estimator 110 is provided as an input to flight control block 160, useful for deriving aircraft flight control signals to achieve a desired aircraft position. For example, flight control 160 may be employed for en-route navigation, terminal approach, and landing of an aircraft.
Before proceeding, it should be noted, as commonly understood in the art, that position estimator 110 employs filtering techniques, such as second order filters or Kalman filters for deriving the aforesaid output information. The position error estimates POS.sub.-- X.sub.-- ERR and POS.sub.-- Y.sub.-- ERR represent the latitude and longitude errors which are related to the differences between the GPS derived position identified as POS.sub.-- GPS and the inertial reference system derived position identified as POS.sub.-- IRS associated with DATA.sub.-- GPS and DATA.sub.-- IRS, respectively.
Further, it should be noted that associated with outputs DATA.sub.-- GPS, DATA.sub.-- IRS, POS.sub.-- HYB, POS.sub.-- X.sub.-- ERR, and POS.sub.-- Y.sub.-- ERR are discrete time values. Accordingly, system timing (not shown) and/or interpolation or extrapolation functions are, of course required, so that position estimator 110 combines the GPS and IRS information for substantially the same time values. In the following exposition, synchronization of time values should be assumed and that each value has a discrete time associated therewith.
As is well-understood in the art, the GPS position solution information must be validated by a GPS system integrity monitor. GPS RAIM processor 150 is intended to operate on the GPS solution information DATA.sub.-- GPS for determining at least horizontal integrity limit values HIL, and may also provide vertical integrity limit values VIL. In turn, these integrity limit values are compared in RAIM Integrity Limit Comparator 155 with selected integrity alarm limit values dependent upon the phase of the flight mission. In turn, if HIL/VIL is acceptable, the pilot will allow control of the aircraft based upon the outputs of position estimator 110. On the other hand, if HIL/VIL exceeds the integrity alarm limit values, the pilot must be alerted so that corrective action may be taken.
A second scenario is, of course, the case where RAIM is unavailable, i.e., insufficient number of tracked satellites. In this scenario, the constellation of satellites as observed by the GPS receiver 120 may be such that it is impossible for GPS RAIM processor 150 to arrive at a solution for obtaining HIL and/or VIL integrity limit values--these being resultant large values for HIL/VIL. Accordingly, GPS integrity validation means 170 is employed to provide an indication as to whether or not there exists RAIM integrity monitoring availability, i.e., sufficient satellite information signals to be able to calculate the integrity limit values, HIL and/or VIL. As illustrated in FIG. 1, GPS integrity validation means 170 receives as its input the GPS receiver output on signal line 122 for making such determination, i.e. RAIM integrity monitoring available or not available, and providing such indication as signal "V" on signal line 172.
As is well understood in the art, GPS integrity validation means 170 represents a simple analysis of the number of satellite information signals tracked by the GPS signal receiver 120 which meet predetermined criteria, e.g., elevation angle. As described earlier, RAIM availability is conditioned upon having at least five satellites tracked for receiving satellite information therefrom. Secondly, GPS RAIM processor 150 is generally operable not to utilize satellite information from those satellites which are less than a selected elevation angle. In this situation, even though a proper number of satellites have been tracked, the information may not be reliable due to the elevation angle of the satellite relative to the user's position. In either case, the function of GPS integrity validation means 170 is to provide an indication of the "non-availability" of RAIM integrity limit values, and is provided as an input to a pilot alert mechanisms indicated by block 180.
It should be noted that blocks 150, 155, and 170 are shown as discrete functional blocks, for explanation purposes. However, it should be understood that they may be incorporated together, and may also be part of the GPS receiver, itself, as should be appreciated by those skilled in the art.
Reliance upon the system as described in FIG. 1 by a pilot is extremely dependent upon RAIM availability. In other words, the user position estimate POS.sub.-- HYB is only useful during those times in which RAIM integrity limit values are available. Loss of RAIM will have adverse consequences, for example, requiring the pilot to abort a terminal approach or landing.
For example, consider the situation in which RAIM is available and an aircraft has already begun the terminal phase of the flight mission prior to landing. Assume now that during this phase of the flight mission that the constellation of satellites changes to a condition in which RAIM integrity monitoring is no longer available. In this scenario, the pilot is alerted via a warning display mechanization 180 or inputs to the flight control system 160 such as to cause the pilot to disengage the flight control system which responds primarily to the aircraft position POS.sub.-- HYB since GPS data may no longer be reliable. In this scenario, depending upon the weather conditions, namely, cloud cover and the like, the pilot must determine whether to manually fly the aircraft, or abort the phase of the flight mission in which RAIM integrity monitoring was lost, i.e., not available. In the latter case, the pilot may take appropriate actions to require some delay time at which the constellation of satellites would be in proper position to provide RAIM integrity monitoring availability.
It should be noted, one technique for avoiding the above scenario, is predictive RAIM. Predictive RAIM attempts to known in advance that RAIM integrity monitoring is available before entering a particular phase of the flight and would be available throughout the entirety of the phase of the flight mission. This is particularly important in the approach and landing phases of the flight mission. If predictive RAIM indicates "non-availability", the pilot may take certain actions, e.g., decrease the aircraft velocity such that landing takes place at a later time when RAIM is once again available.
Illustrated in FIG. 2 is one embodiment of the present invention for providing an alternate GPS integrity limit process during those time periods in which the usual RAIM integrity monitoring is not available. In FIG. 2, similar functioning blocks as those illustrated in FIG. 1 have retained the same numeral designation, and therefore will not be further described. FIG. 2, in addition to those components as shown in FIG. 1, further includes velocity/acceleration error estimator 210, modified IRS position estimator 220, position difference calculator 230, alternate integrity limit comparator 240, and position selector 300.
Before proceeding, it should be understood that GPS position/inertial information processors may provide position/inertial information in a variety of coordinate reference frames. Commonly, GPS information provides position information in an earth-centered, earth-fixed, coordinate reference frame. In turn, this information may be translated into latitude and longitude values. The inertial GPS solution information may include velocity information in terms of north direction and east direction, as is commonly found in the art. These values, of course, are mere translations and/or transformations of the earth-centered, earth-fixed, position information. Accordingly, as depicted in FIG. 2 and the explanation which follows, north and east directions are represented by X and Y, respectively, which also relates to latitude and longitude, respectively. Further, in the following exposition, the term "POS" represents position, and the term "VEL" represents velocity.
Referring again to FIG. 2, velocity/acceleration error estimator 210 receives as inputs (i) GPS derived velocity information in the X and Y direction, and (ii) IRS velocity information in the X and Y direction derived from the inertial sensors, are provided as inputs. These terms may be represented by:
VEL.sub.-- X.sub.-- GPS
GPS derived velocity, X direction
VEL.sub.-- Y.sub.-- GPS
GPS derived velocity, Y direction
VEL.sub.-- X.sub.-- IRS
IRS derived velocity, X direction
IRS derived velocity, Y direction
where the IRS and GPS designate refers to data derived from the inertial reference system 130 and the GPS receiver 120 respectively. As before, these terms have substantially identical corresponding real time values associated therewith.
Velocity/acceleration error estimator 210 provides as an output information designated as "DATA.sub.-- ERROR" which represents discrete acceleration and velocity error, or bias terms in the IRS position/inertial information. Such terms may be represented by VEL.sub.-- X.sub.-- ERR, VEL.sub.-- Y.sub.-- ERR, ACC.sub.-- X.sub.-- ERR, and ACC.sub.-- Y.sub.-- ERR, X and Y velocity and acceleration errors, respectively. Modified IRS position estimator 220 receives as inputs DATA.sub.-- ERROR, the inertial reference system 130 position information represented by POS.sub.-- IRS, the position errors POS.sub.-- X.sub.-- ERR and POS.sub.-- Y.sub.-- ERR, and validation signal on signal lines 332, 134, 114, 116, and 172, respectively.
Modified IRS position estimator 220 is intended to provide an output on signal line 222 representative of a modified IRS position estimate designated as POS.sub.-- IRS.sub.-- LOSS which represents an estimate of the real position of the user during the time period in which GPS RAIM integrity monitoring was not available (i.e., RAIM "LOSS") following a time period when RAIM integrity monitoring was available. Modified IRS position estimator 220 is intended to operate on the aforesaid input information for determining a position estimate which may be mathematically described as follows: ##EQU1##
These terms, of course, having their coordinate components, i.e. X and Y. The above expression is simply a statement that the modified IRS estimated position POS.sub.-- IRS.sub.-- LOSS at time "t" is the measured IRS position POS.sub.-- IRS(t) corrected by the velocity and acceleration error terms provided by Velocity/Acceleration error estimator 300 and the position error estimates provided as an output of position estimator 110--the latter being provided by a filtered error estimator described earlier.
In component terms, then ##EQU2##
Again referring to FIG. 2, the modified IRS position estimate identified as POS.sub.-- IRS.sub.-- LOSS provided on output signal line 222 is presented to position difference calculator 230. Position difference calculator 230 receives as a second input the GPS derived position identified as POS.sub.-- GPS provided on output signal line 129 from GPS receiver 120. Position difference calculator 230 is intended to derive the difference in position D between the GPS derived position and the modified IRS position estimate, as mathematically described by: ##EQU3##
It should be noted that the position difference "D" represents the magnitude of a vector between (a) the position coordinates derived from the GPS solution provided by GPS receiver 120, and (b) the position coordinates derived by the IRS position/inertial information processor 134 as modified by the velocity/acceleration errors DATA.sub.-- ERROR provided as an output of modified IRS position estimator 220, namely POS.sub.-- IRS.sub.-- LOSS. The value "D" represents an "alternate integrity limit" value since it relates to the errors in the IRS system 130 at the time RAIM integrity monitoring was lost. The value D is provided as an output on signal line 232, and presented as an input to alternate integrity limit comparator 240.
Alternate integrity limit comparator 240 receives as inputs the alternate integrity limit value D, and integrity alarm limit reference values identified as reference-I and reference-II, dependent upon the phase of the flight mission. Alternate integrity limit comparator 240 is intended to compare the deviation between the alternate integrity value D and a predetermined flight phase integrity alarm limit value (i.e., the alarm limit reference values). The aforesaid integrity alarm limit value is of course dependent upon the phase of the flight mission (for example, terminal phase, approach phase, or final approach (landing) phase). Alternate integrity limit comparator 240 provides an indication of the alternate integrity comparison designated AIL on signal line 242. In turn, output signal line 242 is presented as an input to position selector 300, and flight control 160.
Position selector 300 receives as inputs, the position estimator 110 derived position POS.sub.-- HYB on signal line 112, and the GPS derived position POS.sub.-- GPS from GPS receiver 120 on output signal line 129. Further, position selector 300 receives as an input, the output V provided by GPS integrity validation means 170, and the output AIL from alternate integrity limit comparator 240 on signal lines 172 and 242. Position selector 300 provides as an output on signal line 332 an estimated position identified as POS.sub.-- SEL dependent upon the output of GPS integrity validation means 170, the alternate integrity limit comparator 240, and the position inputs as aforesaid. This signal is presented to flight control 160.
Operation of the embodiment of the invention depicted in FIG. 2 will now be described.
RAIM Available
Consider the situation in which an aircraft is in the terminal phase of the flight mission, and the constellation of GPS satellites is such the GPS receiver 120 is able to track five or more satellites which have an elevation angles greater than some selected minimum. In these circumstances, GPS RAIM processor 150 receiving the GPS position/solution information, is able to calculate the horizontal integrity limit value HIL. Secondly, GPS integrity validation means 170 outputs V indicating that RAIM is available.
At the same time, position estimator 110 derives an estimated aircraft position POS.sub.-- HYB as a function of the GPS data, identified as DATA.sub.-- GPS and the IRS data, identified as DATA.sub.-- IRS to calculate the estimated position POS.sub.-- HYB by a matter well-known in the art as already described with reference to FIG. 1. Upon receiving a RAIM available signal indication on signal line 172, position selector 300 sets the output 332 such that POS.sub.-- SEL=POS.sub.-- HYB. This estimated position, POS.sub.-- SEL, is provided as an output to flight control 160. In turn, flight control 160 will utilize the estimated aircraft position POS.sub.-- SEL if, and only if, the integrity limit value HIL is below a preselected value. Accordingly, flight control 160 includes pilot alarms, navigation, and flight control processing functions as well-known in the art.
RAIM Changes to Non-Availability
Now consider the situation when the GPS constellation is such that RAIM integrity monitoring is no longer available at time T.sub.L. In these circumstances, modified IRS position estimator 220 (i) acknowledges the fact that RAIM is no longer available, (ii) stores the value of T.sub.L, (iii) stores the velocity/acceleration error estimates presented by DATA.sub.-- ERROR corresponding to time T.sub.L, and (iv) calculates the modified IRS position POS.sub.-- IRS.sub.-- LOSS for time after T.sub.L and until RAIM becomes available again.
In these circumstances, position selector 300 sets POS.sub.-- SEL=POS.sub.-- IRS.sub.-- LOSS. Concurrently, the difference D between the modified IRS position estimate POS.sub.-- IRS.sub.-- LOSS differential and the GPS position solution GPS.sub.-- POS is calculated by position difference calculator 230. Alternate integrity limit comparator 240 compares the output value D with the flight phase alarm limit reference values corresponding to the particular phase of flight. If D is greater than the acceptable limit value reference, the output AIL of alternate integrity limit comparator 240 provides a go/no go indication, AIL, as an input to flight control 160. In these circumstances, the estimated position indicated by POS.sub.-- SEL should not be used for flight control, and that the pilot needs to take corrective action as being appropriate.
RAIM Returns to Available
Upon the GPS satellite constellation changing to a condition at which RAIM is now available, position selector 300 will set its output POS.sub.-- SEL to POS.sub.-- HYB as before.
FIG. 3 illustrates one embodiment of a velocity/acceleration error estimator 210 in the form of a second order filter. The nomenclature shown in FIG. 3 is for the "X" direction, and a similar implementation is required for the "Y" direction. Thereshown is block 310 for forming the difference calculations between the GPS derived velocity value and the IRS derived velocity value for the X direction as identified by: VEL.sub.-- X.sub.-- GPS, and VEL.sub.-- X.sub.-- IRS, respectively.
In turn, block 320 forms the difference between the output of block 310 and the velocity error term VEL.sub.-- X.sub.-- ERR. The filter further includes integrator 330 and integrator 380, value limiters 340 and 385, and gain blocks 360 and 365.
As illustrated, the acceleration error term "ACC.sub.-- X.sub.-- ERR" is equal to the output of limiter block 340 multiplied by gain block 365, integrated by integrator 380, and subsequently being passed through limit block 385. The velocity error term VEL.sub.-- X.sub.-- ERR being substantially equal to the output of limit block 340 passing through gain block 360 and summed with the acceleration error term ACC.sub.-- X.sub.-- ERR before being integrated by block 330, forming the velocity error term.
The foregoing description of the present invention has been described in terms of simplified schematic block diagrams where each one of the blocks generally employs complex systems employing specific software for executing complex mathematical functions for deriving the intended information. It should be recognized that these schematic block diagrams particularly illustrated in the Figures may be configured by employment of many electronic subsystems, computers and software/firmware implementations. The signal lines, shown in singular form, may represent one or more data buses for providing the intended information as should be appreciated by those skilled in the art. Further, as is well-understood in the art, a single electronic/software subsystem may be employed for performing the appropriate calculations for the generation of all of the described data, except for the details of the GPS signal receiver for receiving the GPS satellite information signals, as well as the inertial sensors themselves. All of these variations as just described are intended to be within the true spirit and scope of the present invention.
Although the present invention has particular applicability to flight control for aircraft or spacecraft, and the like, it is intended to be within the true spirit and scope of the present invention for applications beyond that of flight control.
Lastly, although the velocity and acceleration error estimator has been illustrated by employment of a simple second order filter, other filters are within the scope of the present invention, for example a six or nine state Kalman filter to include the funciton of block 130.
By way of the Figures illustrated herein, a technique has been disclosed for estimating the velocity and acceleration errors of an inertial reference system by processing GPS derived velocity information and IRS derived velocity information in a second order filter for a subsequent determination of an IRS derived user position modified by the aforesaid velocity and acceleration errors. The error estimates are frozen at a time when the GPS satellite information signals are sufficient to provide a RAIM integrity. However, when the RAIM integrity information is not available, but the GPS position solution had been deemed to have adequate accuracy prior to loss of RAIM availability, a real time IRS user position is modified with these estimated velocity and acceleration errors to provide a highly reliable user position in the absence of RAIM integrity. In turn, an alternate integrity limit value is established, that value being the magnitude of difference between the current GPS position POS.sub.-- GPS and the modified IRS position estimate, POS.sub.-- IRS.sub.-- LOSS.
The IRS position POS.sub.-- IRS modified by the velocity and acceleration error estimates IRS.sub.-- POS.sub.-- LOSS is based on an assumed inertial reference system error model. This model reflects accurately the fact, that in the short term, the inertial reference system performance is governed by the velocity errors. In the absence of any calibration of these errors, the logical practice is to assume their specification limits. For this reason, the 99.9 percentile value assumed for the position error growth rate can be as high as 12 nautical miles per hour. This value, when used in IRS based alternate integrity computations, reaches an alarm limit of 0.3 nautical miles (typical for approach phase of the mission) in 1.5 minutes. But, in accordance with the present invention, the estimated velocity errors correct the IRS velocities, thereby reducing the value of any residual errors. Further, the accuracy of the alternate user position, POS.sub.-- IRS.sub.-- LOSS made using both velocity and acceleration error estimates, is considerably enhanced. It is believed that the residual errors in the computations are at most of the order of 3 nautical miles per hour on a 99.9 percentile basis. At this rate, alarm limits of 0.3 nautical miles will be reached in six minutes, a four-fold improvement over current implementations.
1. A combined inertial reference system and a satellite positioning system for determining user position comprising:
an inertial reference system employing inertial sensors for providing IRS position and inertial reference information, including IRS velocity information, derived from output information from said inertial sensors;
a satellite positioning system receiver for providing a GPS position solution including a resultant GPS position and resultant GPS velocity information derived form satellite information from signals transmitted from a plurality of satellites;
validation means responsive to at least the number of said plurality of satellites transmitting said satellite information signals for indicating a non-availability time period when said number is below that which is required to provide at least one integrity limit value associated with the accuracy of said GPS solution, as opposed to an integrity time period when said number is sufficient to provide said at least one integrity limit value;
error estimator means for determining velocity and acceleration error estimates associated with said IRS inertial information as a function of said IRS velocity information and said resultant GPS velocity information;
coast position estimator means for determining a first estimated position of the user's position during said non-availability time period as function of said velocity and acceleration error estimates occurring at the beginning of said non-availability time period, the elapsed time accumulated since the beginning of said non-availability time period, and the IRS position.
2. The combined inertial reference system and a satellite positioning system of claim 1 further comprising:
IRS/GPS position solution determining means for determining a second estimated position of the user's position as a function of a t least said IRS position and inertial information and said resultant GPS position and resultant GPS velocity information;
position selector means for providing as an output thereof said second estimated position for time during an integrity time period, and said first estimated position for time during a non-availability time period.
3. The combined inertial reference system and a satellite positioning system of claim 1 wherein said error estimator means provides a second order filter having as it input the difference between corresponding components of said resultant GPS velocity and said IRS velocity.
4. The combined inertial reference system and a satellite positioning system of claim 3 wherein said error estimator means includes (i) a second order filter having as its input the difference between north direction components of said resultant GPS velocity and said IRS velocity, and as outputs corresponding north direction velocity and acceleration bias values, and (ii) a second order filter having as it input the difference between east direction components of said resultant GPS velocity and said IRS velocity, and as outputs the corresponding east direction velocity and acceleration bias values.
5. An apparatus for determining the position of a vehicle, the apparatus comprising:
a global positioning system (GPS) communicating with a plurality of satellites and providing a GPS position signal;
an inertial reference system (IRS) providing an IRS position signal;
a position estimator providing a hybrid position signal based upon th eGPS position signal and the IRS position signal;
an IRS position estimator providing an estimated IRS position signal based upon the IRS position signal, the velocity of the vehicle, and the acceleration of the vehicle; and
a position selector providing a vehicle position signal, wherein the vehicle position signal corresponds to the hybrid position signal when the GPS position signal is reliable, and wherein the vehicle position signal corresponds to the estimated IRS position signal when the GPS position signal is unreliable.
6. The apparatus of claim 5 wherein the GPS position signal is unreliable when receiver autonomous integrity module (RAIM) information is unavailable from the global positioning system.
7. The apparatus of claim 5 wherein the GPS position signal is unreliable when the global positioning system communicates with fewer than five satellites.
8. The apparatus of claim 5 further comprising a RAIM availability module that receives the GPS position signal and provides a RAIM availability signal to the position selector.
9. The apparatus of claim 5 further comprising a RAIM availability module that receives the GPS position signal and provides a RAIM availability signal to the IRS position estimator.
10. The apparatus of claim 5 further comprising a velocity/acceleration error estimator that receives a GPS velocity based upon the velocity of the vehicle from the global positioning system and provides a data error signal to the IRS position estimator.
11. The apparatus of claim 5 further comprising a velocity/acceleration error estimator that receives an IRS velocity based upon the velocity of the vehicle from the inertial reference system and provides a data error signal to the IRS position estimator.
12. The apparatus of claim 10 further comprising a velocity/acceleration error estimator that receives an IRS velocity based upon the velocity of the vehicle from the inertial reference system.
13. The apparatus of claim 11 wherein the velocity/acceleration error estimator comprises a second order filter.
15. A method of determining the position of a vehicle having a velocity and an acceleration, the method comprising the steps of:
providing a GPS position signal from a global positioning system;
providing an IRS position signal from an inertial navigation system;
determining if the GPS position signal is reliable;
providing a hybrid position signal to a flight control when the GPS position signal is reliable, the hybrid position signal being based upon the GPS position signal and the IRS position signal; and
providing an estimated IRS position signal to a flight control when the GPS position signal is unreliable, the estimated IRS position signal being based upon the velocity of the vehicle, the acceleration of the vehicle and the IRS position signal.
16. The method of claim 15 wherein the velocity of the vehicle and the acceleration of the vehicle are monitored by the global positioning system.
17. The method of claim 15 wherein the velocity of the vehicle and the acceleration of the vehicle are monitored by the inertial reference system.
19. The method of claim 15 further comprising the steps of:
determining if the estimated IRS position signal is reliable; and
providing an indication to a pilot of the vehicle if the estimated IRS position signal is not reliable.
4806940 February 21, 1989 Harral et al.
5394333 February 28, 1995 Kao
5461388 October 24, 1995 Applegate et al.
5504482 April 2, 1996 Schreder
5504492 April 2, 1996 Class et al.
5512903 April 30, 1996 Schmidke
5543804 August 6, 1996 Buchler et al.
5583774 December 10, 1996 Diesel
5606506 February 25, 1997 Kyrtsos
5657025 August 12, 1997 Ebner et al.
0 629 877 December 1994 EPX
95 34850 December 1995 WOX
Article entitled Minimum Operational Performance Standards for Airborne Supplemental Navigation Equipment Using Global Positioning System (GPS), document No. RTCA/DO-208, Jul. 1991, prepared by: SC-159, pp. 19-22. Appendix F entitled "Least-Squares Residuals RAIM Method" from document No. RTCA/DO-208, Jul. 1991, prepared by SC-159, pp. 1-4. Article entitled "Implementation of a RAIM Monitor and a GPS Receiver and an Integrated GPS/IRS" by Mats Brenner, in the proceedings of ION GPS-90, Third International Technical Meeting of the Satellite Division of the Institute of Navigation, Sep. 19-21, 1990, located at p. 397. Patent Abstracts of Japan, vol. 013, No. 135 (p-851), Apr. 5, 1989.
Filed: Oct 23, 1996
Date of Patent: Jul 13, 1999
Assignee: Honeywell Inc. (Minneapolis, MN)
Inventor: Sudhakar P. Divakaruni (Scottsdale, AZ)
Primary Examiner: Thomas Tarcza
Assistant Examiner: Dao L. Pham
Attorneys: Charles J. Ungemach, Ronald E. Champion
Current U.S. Class: 342/357; 701/213
International Classification: G01S 502; H04B 7185;


text:
AR Podcasts
Activist's Corner
Interviews & Appearances
Send Us News Stories
More Children in Britain Born to Polish Mothers than Those from Any Other Foreign Country
Jack Doyle, Daily Mail (London), September 19, 2011
More than one in every 40 newborns in the UK are born to Polish mothers, it has emerged.
More children are born in Britain to women from Poland than those from any other foreign country, research shows.
Last year nearly 20,000 babies were born to Polish migrants–that is more than 50 a day and amounts to one in every 37 newborns.
Official figures show that in just six years the number of children born to Polish women has increased nearly six-fold. In 2005–the year after Britain opened its borders to workers from the former Eastern Bloc countries–the number was lower than 3,500.
The figures illustrate the scale and speed of Polish migration since the expansion of the European Union, and the effects of the Labour government's decision not to impose restrictions on worker numbers.
The so-called 'migrant baby boom' means that across the country, one in four of all children is born to a mother who was born overseas.
That figure has doubled in just ten years as migrant numbers have exploded.
Sir Andrew Green, chairman of Migrationwatch, said: 'This is an extraordinary increase. There must be concern that the numbers will grow even more rapidly now that Eastern Europeans have full access to the welfare state in Britain.'
Department of Health figures show the number of children born here to Polish mothers hit a new high last year.
Between 2001 and 2009, mothers from Pakistan gave birth to the highest number of foreign-born babies in England and Wales, but last year it was women from Poland.
The figures show that there were 1,392 births to Polish mothers in 2003, the year before EU expansion, and this rose to 1,830 the following year.
In 2005, it nearly doubled to 3,403 and then rose sharply again to 6,620 in 2006. Last year the figure stood at 19,762. Poland is one of the former Eastern Bloc countries which joined the EU in 2004, and the Government is hamstrung in its ability to restrict immigration.
Before the door was opened, Labour predicted 13,000 migrants would come to this country as a result.
But with other EU counties restricting access to their labour markets, Britain became a target destination for workers.
Since 2004, up to 900,000 Poles have been granted a National Insurance number, which is needed for them to get a job.
At the peak, between 2006 and 2008, some 20,000 Poles every month were coming to the UK for work.
Numbers of Eastern Europeans fell during the recession but have picked up again in recent months–despite no sign of an economic recovery.
British taxpayers fork out for child benefit payments to tens of thousands of migrant workers, because EU rules allow them to live at home while claiming here. Approximately 50,000 children of migrant workers receive the benefit–even though the youngsters still live in their home countries.
Treasury figures show that Poles make up the vast majority of the payments–accounting for 37,941 children last year–at a cost of £24million a year.
Critics say the flood of arrivals has placed huge pressure on housing, education and the health service–especially maternity units.
The Polish influence has also been felt in schools. Five years ago, just 200 students sat a Polish GCSE–last year, the figure was 1,900.
Figures for the numbers of children born to foreign-born mothers in specific regions of the country are not broken down by individual countries.
But figures show Eastern European migrant mothers accounted for more than one in four babies in Boston, Lincolnshire. In total last year, one in every four children born in England and Wales was to a foreign-born mother–a total of 181,827 children.
In May, rules restricting access to welfare benefits for Eastern European workers coming to Britain were scrapped because of EU rules restricting how long they can be held in place–raising fears of mass benefits tourism.
Topics: Eastern Europe, Immigration, Poland
< Africville Heritage Trust Defends Hiring White Woman as Director
Sperm Bank Turns Down Redheads >
Forced Busing in Lansing, Michigan
World Economic Forum Versus the First Amendment
'The Black Race Is a Lost Cause'
Being White on Martin Luther King, Jr. Day
Annual 2023 Reverend Doctor Martin Luther King, Jr. Day History Quiz
Toward A Harmonious Racial Disengagement
Sanity in Minnesota
The Jackpot Keeps Growing
AR Archives
The contents of this website are copyright © 1990-2023 New Century Foundation.

redpajama_set_name: RedPajamaCommonCrawl


text:
Cryogenic Transport of High-Pressure-System Recharge GasA method of relatively safe, compact, efficient recharging of a high-pressure room-temperature gas supply has been proposed. In this method, the gas would be liquefied at the source for transport as a cryogenic fluid at or slightly above atmospheric pressure. Upon reaching the destination, a simple heating/expansion process would be used to (1) convert the transported cryogenic fluid to the room-temperature, high-pressure gaseous form in which it is intended to be utilized and (2) transfer the resulting gas to the storage tank of the system to be recharged. In conventional practice for recharging high-pressure-gas systems, gases are transported at room temperature in high-pressure tanks. For recharging a given system to a specified pressure, a transport tank must contain the recharge gas at a much higher pressure. At the destination, the transport tank is connected to the system storage tank to be recharged, and the pressures in the transport tank and the system storage tank are allowed to equalize. One major disadvantage of the conventional approach is that the high transport pressure poses a hazard. Another disadvantage is the waste of a significant amount of recharge gas. Because the transport tank is disconnected from the system storage tank when it is at the specified system recharge pressure, the transport tank still contains a significant amount of recharge gas (typically on the order of half of the amount transported) that cannot be used. In the proposed method, the cryogenic fluid would be transported in a suitably thermally insulated tank that would be capable of withstanding the recharge pressure of the destination tank. The tank would be equipped with quick-disconnect fluid-transfer fittings and with a low-power electric heater (which would not be used during transport). In preparation for transport, a relief valve would be attached via one of the quick-disconnect fittings (see figure). During transport, the interior of the tank would be kept at a near-ambient pressure far below the recharge pressure. As leakage of heat into the tank caused vaporization of the cryogenic fluid, the resulting gas would be vented through the relief valve, which would be set to maintain the pressure in the tank at the transport value. Inasmuch as the density of a cryogenic fluid at atmospheric pressure greatly exceeds that of the corresponding gas in a practical high-pressure tank at room temperature, a tank for transporting a given mass of gas according to the proposed method could be smaller (and, hence, less massive) than is a tank needed for transporting the same mass of gas according to the conventional method.
Ungar, Eugene K, (NASA Johnson Space Center Houston, TX, United States)
Ruemmele, Warren P. (NASA Johnson Space Center Houston, TX, United States)
Bohannon, Carl (Boeing Co. Houston, TX, United States)


text:
Report on Special Conference of LMCs - 31 Jan 2016
The Humberside Group of LMCs was represented at the Conference by:
Dr Andrea Fraser (Chair, North & North East Lincolnshire LMC)
Dr Anne Jeffreys (Chair, Hull & East Yorkshire LMC)
Dr Zoë Norris
Dr Karena Platts
Dr Russell Walshaw attended as an Observer
There were eight main subject headings and in each heading were one or more motions constructed from the hundreds of motions submitted by the LMCs. This conference was different in that we only debated 16 motions in a day instead of the usual 40 normally debated in one day.
A webcast of the full conference is still available on the BMA website at:
http://www.bma.org.uk/lmcconference
At the beginning John Canning proposed that the agenda as set should be rejected and the conference should determine what it wanted to debate. After much debate the conference voted to proceed as set out in the Agenda papers. Whereas many representatives stated that the composite motions were not appropriate for addressing the crisis it was nevertheless the LMCs that had submitted all the motions. Once the procedural discussions had been resolved the conference opened with a report from the Chairman of the GPC, Dr Chaand Nagpaul which was received with a standing ovation.
The full text of the speech at:
http://www.bma.org.uk/working-for-change/negotiating-for-the-profession/bma-general-practitioners-committee/special-lmc-conference/special-lmc-conference-speech
At a later slot there was also a short speech from Dr Maureen Baker which outlined the RCGP view and this is available at:
http://www.rcgp.org.uk/news/2016/january/maureen-baker-speech-lmcs-conference.aspx
Details of the debates are shown in the chart below. The gist of the steps forward can be summarised essentially as:
1. A minimum of 11% of NHS total budget spent in general practice
2. Removal of premises negative equity trap via a "purchaser of last resort" measure
3. Accelerated, standardised and funded national returner scheme
4. Suspension of the appraisal and inspection regime
5. Politician-led public measures (including contractual changes) to limit demand during our "state of emergency"
The subject areas debated were as follows:
Future of the NHS


Bahrain (officially the Kingdom of Bahrain), is a small island country situated near the western shores of the Persian Gulf. It is an archipelago with Bahrain Island, the largest land mass, at 55 km long by 18 km wide. Saudi Arabia lies to the west and is connected to Bahrain by the King Fahd Causeway while Iran lies 200 km to the north across the Persian Gulf. The peninsula of Qatar is to the southeast across the Gulf of Bahrain. The population in 2010 stood at 1,234,571, including 666,172 non-nationals.


text:
The Stolen Generations
Michael Jacklin, University of WollongongFollow
Jacklin, M, The Stolen Generations, Biblio: A Review of Books, 14(11&12), 2009, p 37.
Since the coming of the Europeans, Australia's ecosystems have been challenged by exotic, introduced species which, once established, quickly spread and threaten both native species and environmental balance. Jim Bloke, the first-person narrator of Bruce Pascoe's new novel, is unaware of the most recent of these biotic challenges – abalone virus ganglioneuritis or AVG – when chance brings him into the small East Gippsland town of Nullakarn. Soon after settling in at the local pub – before he's got the foam off the top of his third beer – he's been offered a place on the local footy team and a job as an oyster harvester. But if this ordinary bloke's luck seems too good to be true, it's because it is. Oyster work leads to diving for sea urchins, leads to abalone harvesting, leads to trips to Singapore to bring boats with unknown cargo back to Australia and this, of course, leads to trouble with the law – trouble that relates, ultimately to the "ganglio" that threatens the abalone industry along the Victorian coast. With Bloke, Pascoe spins a yarn that effectively combines the crimethriller genre with a search-for-identity narrative, along with romance, humour and, as in all of Pascoe's work, Aboriginality.
Link to publisher version (URL)
Arts and Humanities Commons, Social and Behavioral Sciences Commons


In March 1992, an important new venue opened on the Internet--one in which users worldwide could meet in a common electronic window and not only see and talk to one another, but work on a shared "whiteboard." But despite its popularity within the select group that used the new technology--called the Multicast Backbone, or M-Bone--few others knew of its existence.
That began to change two weeks ago. Mick Jagger and the Rolling Stones brought their "Voodoo Lounge" concert to M-Bone, performing for 50,000 people in Dallas' Cotton Bowl as well as a small audience at workstations around the world. The event made international news, and brought M-Bone into prominence.
Van Jacobson of LBL's Information and Computing Science Division is one of the three principal creators of M-Bone. The others are Steve Deering, of Xerox Corp.'s Palo Alto Research Center, and Steve Casner of the University of Southern California. Deering and Casner developed the protocols that make the virtual network possible, and Jacobson created many of the tools that make it valuable.
As Jacobson told Newsweek magazine in a December 5 article, the Stones' concert should inspire new ways to use the medium. But well before Jagger strutted online, more than 10,000 people in 30 countries routinely used the M-Bone for collaborative work.
In multicasting, rather than send information to a single location, the network distributes it from senders to every receiver who has signed up for the session. While simple in concept, the magic underlying M-Bone is its ability to dynamically construct distribution trees using the shortest, most efficient paths. Because M-Bone usually includes live video, which means huge volumes of traffic, efficiency was a prerequisite to prevent congestion and collapse of the Internet.
M-Bone was first used to simulcast the March 1992 Internet Engineering Task Force conference. Since then, it has provided around-the-clock coverage of space shuttle flights, an opportunity for surgeons to observe and question a San Francisco surgeon performing a complex liver operation, and a place for Ph.D. candidates to defend their dissertations to committee members.
"The tools are so easy to use that anybody can announce a session and be their own producer," Jacobson says. "Somebody actually sent out to the universe live pictures of their pet iguana climbing a tree."
The heaviest use of M-Bone has been by network researchers to conference and collaborate with each other. It offers a number of advantages over teleconferencing, which joins a few sites with expensive dedicated transmission lines. M-Bone links anyone to the Internet who has a workstation with audio/video capabilities and a high-speed connection. Jacobson says this flexibility has resulted in moves by both NASA and DOE to replace teleconferencing with M-Bone meetings.
Jacobson's research group at LBL includes Steve McCanne and Sally Floyd. Jacobson and McCanne designed the whiteboard, which Jacobson calls an "infinite piece of paper." It allows participants in an M-Bone session to write, type, and draw on a shared drawing window. It even has a memory, so that those using it can flip pages, scrolling back to earlier versions of the contents, or import other drawings and text.
Jacobson also developed the session directory, a conference coordination tool that provides a menu of what is currently available or upcoming on M-Bone. The Session Directory allows the user to join a session, or to announce and advertise an upcoming session.
The tool pack developed by Jacobson's group also includes VIC (Video Conferencing) and VAT (Visual Audio Tool). These make it possible for all parties to both talk and listen. It also makes possible the transmission of a video stream to an unlimited number of participants.
Currently, Jacobson says, M-Bone is handicapped in that most of the routers that forward packets around the Internet do not support the Internet Protocol multicast addressing system developed by Deering. In the next year, new commercial routers are scheduled to be introduced that support multicasting. As this happens and as efficiency improves, Jacobson predicts that multicasting will become so ubiquitous that M-Bone will essentially disappear as a distinct entity on the Internet.


Unicorn kisses make everything better. Look after any grazes, bumps or blisters with these deluxe multi-coloured plasters featuring unicorns, rainbows and sparkles to make you smile again. Stylish tin holds 24 sticking plasters in a variety of shapes and sizes.


Co-operation in the field of higher education and between higher education institutions is one of the hallmarks of European Integration – both within the European Union and the Council of Europe. This project assists Bosnia and Herzegovina to achieve one of the aspects of its strategic development plan for education 2008-2015: full accession to the European Higher Education Area (EHEA). The goal is to enable BiH higher education, its institutions, graduates, academics and students to benefit fully from European opportunities and to play its full role for development in Bosnia and Herzegovina (BiH).
The project helps strengthen expertise and capacities within the country and builds on a series of previous joint projects of the European Commission and the Council of Europe supporting higher education reforms in Bosnia and Herzegovina since it joined the Bologna Process in 2003.
The two year project was launched in early 2013 at the request of the BiH authorities and is co-financed by the EC's Instrument for Pre-Accession Assistance (IPA 2011) and the Council of Europe.
It is run out of the Council of Europe's Sarajevo office, with support and expertise of the Council of Europe's Directorate of Democracy (DGII) and its international expert network.


text:
import numpy as np
import os
import datashape as ds
import pytest
from toolz import first

from blaze import into
from blaze.utils import tmpfile
from blaze.compatibility import xfail
from blaze import PyTables, discover
import pandas as pd

tb = pytest.importorskip('tables')

try:
    f = pd.HDFStore('foo')
except (RuntimeError, ImportError) as e:
    pytest.skip('skipping test_hdfstore.py %s' % e)
else:
    f.close()
    os.remove('foo')

now = np.datetime64('now').astype('datetime64[us]')

@pytest.fixture
def x():
    y = np.array([(1, 'Alice', 100),
                  (2, 'Bob', -200),
                  (3, 'Charlie', 300),
                  (4, 'Denis', 400),
                  (5, 'Edith', -500)],
                 dtype=[('id', '<i8'), ('name', 'S7'), ('amount', '<i8')])
    return y

@pytest.yield_fixture
def tbfile(x):
    with tmpfile('.h5') as filename:
        f = tb.open_file(filename, mode='w')
        d = f.create_table('/', 'title',  x)
        d.close()
        f.close()
        yield filename

@pytest.fixture
def raw_dt_data():
    raw_dt_data = [[1, 'Alice', 100, now],
                   [2, 'Bob', -200, now],
                   [3, 'Charlie', 300, now],
                   [4, 'Denis', 400, now],
                   [5, 'Edith', -500, now]]

    for i, d in enumerate(raw_dt_data):
        d[-1] += np.timedelta64(i, 'D')
    return list(map(tuple, raw_dt_data))

@pytest.fixture
def dt_data(raw_dt_data):
    return np.array(raw_dt_data, dtype=np.dtype([('id', 'i8'),
                                                 ('name', 'S7'),
                                                 ('amount', 'f8'),
                                                 ('date', 'M8[ms]')]))

@pytest.yield_fixture
def dt_tb(dt_data):
    class Desc(tb.IsDescription):
        id = tb.Int64Col(pos=0)
        name = tb.StringCol(itemsize=7, pos=1)
        amount = tb.Float64Col(pos=2)
        date = tb.Time64Col(pos=3)

    non_date_types = list(zip(['id', 'name', 'amount'], ['i8', 'S7', 'f8']))

    # has to be in microseconds as per pytables spec
    dtype = np.dtype(non_date_types + [('date', 'M8[us]')])
    rec = dt_data.astype(dtype)

    # also has to be a floating point number
    dtype = np.dtype(non_date_types + [('date', 'f8')])
    rec = rec.astype(dtype)
    rec['date'] /= 1e6
    with tmpfile('.h5') as filename:
        f = tb.open_file(filename, mode='w')
        d = f.create_table('/', 'dt', description=Desc)
        d.append(rec)
        d.close()
        f.close()
        yield filename

class TestPyTablesLight(object):
    def test_read(self, tbfile):
        t = PyTables(path=tbfile, datapath='/title')
        shape = t.shape
        t._v_file.close()
        assert shape == (5,)

    def test_write_no_dshape(self, tbfile):
        with pytest.raises(ValueError):
            PyTables(path=tbfile, datapath='/write_this')

    @xfail(raises=NotImplementedError,
           reason='PyTables does not support object columns')
    def test_write_with_bad_dshape(self, tbfile):
        dshape = '{id: int, name: string, amount: float32}'
        PyTables(path=tbfile, datapath='/write_this', dshape=dshape)

    def test_write_with_dshape(self, tbfile):
        f = tb.open_file(tbfile, mode='a')
        try:
            assert '/write_this' not in f
        finally:
            f.close()
            del f

        # create our table
        dshape = '{id: int, name: string[7, "ascii"], amount: float32}'
        t = PyTables(path=tbfile, datapath='/write_this', dshape=dshape)
        shape = t.shape
        filename = t._v_file.filename
        t._v_file.close()

        assert filename == tbfile
        assert shape == (0,)

    @xfail(reason="Don't yet support datetimes")
    def test_table_into_ndarray(self, dt_tb, dt_data):
        t = PyTables(dt_tb, '/dt')
        res = into(np.ndarray, t)
        try:
            for k in res.dtype.fields:
                lhs, rhs = res[k], dt_data[k]
                if (issubclass(np.datetime64, lhs.dtype.type) and
                    issubclass(np.datetime64, rhs.dtype.type)):
                    lhs, rhs = lhs.astype('M8[us]'), rhs.astype('M8[us]')
                assert np.array_equal(lhs, rhs)
        finally:
            t._v_file.close()

    def test_ndarray_into_table(self, dt_tb, dt_data):
        dtype = ds.from_numpy(dt_data.shape, dt_data.dtype)
        t = PyTables(dt_tb, '/out', dtype)
        try:
            res = into(np.ndarray, into(t, dt_data, filename=dt_tb, datapath='/out'))
            for k in res.dtype.fields:
                lhs, rhs = res[k], dt_data[k]
                if (issubclass(np.datetime64, lhs.dtype.type) and
                    issubclass(np.datetime64, rhs.dtype.type)):
                    lhs, rhs = lhs.astype('M8[us]'), rhs.astype('M8[us]')
                assert np.array_equal(lhs, rhs)
        finally:
            t._v_file.close()

    def test_datetime_discovery(self, dt_tb, dt_data):
        t = PyTables(dt_tb, '/dt')
        lhs, rhs = map(discover, (t, dt_data))
        t._v_file.close()
        assert lhs == rhs

    def test_no_extra_files_around(self, dt_tb):
        """ check the context manager auto-closes the resources """
        assert not len(tb.file._open_files)

redpajama_set_name: RedPajamaGithub


Partridge Pea Plantation is cradled by the Ichawaynochaway creek in Southwest Georgia. We provide full and half day quail hunts that include guides, dogs, jeeps, and more. Lodging for 8 and additional meals can be arranged. We look forward to providing you lasting memories that brings folks back to the quiet pine woods of Partridge Pea Plantation.


text:
Q: How to make my own package install external packages by default I have a question about installing external packages within my own package. Let's say my package requires two packages : ggplot2 and TTR. I create a new .R file which was saved in package R folder with code following :
#' mypackage
#'
#' @docType package
#' @name mypackage
#' @import ggplot2
#' @import TTR
NULL

Now @import command by default does not install lacking packages. During my package installation I get information that there is no package TTR. This problem does not occur when I manually install TTR package. Then @import command works properly and recognize TTR package. My question is : how can I tell @import command to also install lacking packages ? I tried load_all but it's not working.

A: The problem you are probably encountering is that your package needs to be on CRAN so that install.packages also installs the external packages according to the value of the dependencies argument.
The reason for this is that install.packages assumes that the dependencies are located at the same place as your package.
If your package is a local .tar.gz or .zip file, you can use :
devtools::install_local('mypackage.tar.gz')

This will automatically get the CRAN dependencies defined in @import

A: When you want to add external packages to your package, have have to do the following:

*

*add package in DESCRIPTION file

*@import in .R file for roxygen2
In the description file you have to add a line:
Imports:
    stats,
    grDevices,
    ggplot2

In your .R file, when using roxygen2 you have to add a line:
#' @import ggplot2

roxygen2 then automatically adds ggplot2 to the NAMESPACE file for you (where it needs to be).
When somebody installs your package, ggplot2 will now be automatically be installed.
Just speculation, but maybe the problem was, that you or the user did not actually install the package, but instead has opened the .Rproj file and tried to build the package. Then I think you have to have the installed the package before manually.
Try to build your package. You get a tar.gz / .tgz and install the package in R Studio under Tools -> Install packages or with the install.packages command.

redpajama_set_name: RedPajamaStackExchange


Best price unicorn princess hairband silver, this product is a preferred item this season. the product is really a new item sold by Rainbow Unicorn store and shipped from Singapore. Unicorn princess hairband (Silver) can be purchased at lazada.sg which has a very cheap cost of SGD15.90 (This price was taken on 15 June 2018, please check the latest price here). what are features and specifications this Unicorn princess hairband (Silver), let's wait and watch information below.
Soft and gentle to your skin.
Great for both kids and adults.
For detailed product information, features, specifications, reviews, and guarantees or another question which is more comprehensive than this Unicorn princess hairband (Silver) products, please go straight away to owner store that is due Rainbow Unicorn @lazada.sg.
Rainbow Unicorn is a trusted shop that already has experience in selling Hair Accessories products, both offline (in conventional stores) and online. lots of the clientele are incredibly satisfied to get products in the Rainbow Unicorn store, that could seen with the many elegant reviews written by their clients who have obtained products inside the store. So there is no need to afraid and feel worried about your products not up to the destination or not relative to what is described if shopping from the store, because has several other clients who have proven it.
Furthermore Rainbow Unicorn provide discounts and product warranty returns when the product you get does not match that which you ordered, of course together with the note they supply. Such as the product that we're reviewing this, namely "Unicorn princess hairband (Silver)", they dare to provide discounts and product warranty returns if the products you can purchase do not match what is described.
So, if you want to buy or try to find Unicorn princess hairband (Silver) then i highly recommend you acquire it at Rainbow Unicorn store through marketplace lazada.sg.
Why should you buy Unicorn princess hairband (Silver) at Rainbow Unicorn shop via lazada.sg?
Of course there are numerous benefits and advantages available while you shop at lazada.sg, because lazada.sg is really a trusted marketplace and also have a good reputation that can present you with security coming from all forms of online fraud. Excess lazada.sg in comparison with other marketplace is lazada.sg often provide attractive promotions such as rebates, shopping vouchers, free freight, and often hold flash sale and support that's fast and that's certainly safe. and what I liked happens because lazada.sg can pay on the spot, that has been not there in any other marketplace.


Whether designing for a printed newspaper ad, annual report, fundraising mailing or brochure, each project must be carefully planned and executed. While the worldwide web presents many opportunities, print is still a critical component in the marketing mix.
Below are some printed design samples. To see additional work or to discuss how to best reach your audience within your budget, call (402) 556-5302 or contact Visual Statements electronically.


text:
All Pretoria News
pretoria news
Former top judge named as interim premier
Pretoria News / 29 May 2018, 10:45am / Reuters
Former chief justice of Pakistan Nasirul Ul Mulk has been named the country's caretaker prime minister to oversee the general elections scheduled for July 25. Picture: www.financialexpress.com
ISLAMABAD: Pakistan yesterday appointed former chief justice Nasir-Ul-Mulk as interim prime minister until general elections on July 25, which are expected to usher in the second ever democratic transition of power in the nuclear-armed nation of 208 million people.
The interim administration does not usually make any major decisions until the new government is elected, although it may be forced to act to shore up the economy amid a worsening macro-economic outlook.
Yesterday's appointment, which was announced by Prime Minister Shahid Khaqan Abbasi, comes amid growing political and economic instability, and ends weeks of wrangling between Abbasi's ruling Pakistan Muslim League-Nawaz (PML-N) party and the opposition.
"No Pakistani can lift a finger against such a name," Abbasi told reporters while seated next to Syed Khurshid Ahmed Shah, the leader of the opposition Pakistan People's Party (PPP).
Unlike the run-ups to the previous two elections, which were marred by frequent attacks by Islamist militants, Pakistan has seen a sharp decline in militancy over the past few years.
But allegations of interference by the powerful military have returned in a serious way ahead of the July election, with PML-N accusing the military of trying to weaken it.
The military, which has ruled Pakistan for about half its history since independence in 1947, denies meddling in politics.
Mulk, who also served as the interim chief of the Election Commission of Pakistan (ECP), will head a technocratic government after the current government and parliament are dissolved on Thursday.
Tasks awaiting the next government's attention range from tackling Pakistan's growing international isolation and souring ties with the US to fixing the economy and a growing reliance on Chinese loans to stay afloat.
Aamer Ahmed Khan, a Pakistani journalist and political analyst, said PML-N's efforts to drag out the talks was an attempt to signal to voters its concerns about interference in the elections.
"If anything, the apparent agreement has only reinforced the cynicism of the incumbent party towards the health and transparency of the upcoming elections," Khan said.
The main electoral challenge to PML-N, which has been weakened since its founder Nawaz Sharif was ousted as premier by the Supreme Court, is expected to come from the Pakistan Tehrik-e-Insaf, or Justice Party, which is headed by cricketer-turned-politician Imran Khan.
Mulk was a surprise choice for the role of prime minister, with PPP's Shah saying he was not the front-runner when the ruling party and the opposition began discussing the six likely candidates.
Mulk "enjoys a good reputation", said Raza Ahmad Rumi, the editor of the Daily Times.
"He's seen as a neutral judge in the past without any political affiliation," Rumi said. He warned that the ECP may have an even bigger role to play in the run-up to the election, and had not been properly reformed. - Reuters


text:
Cyber Defense
IARPA wants an early warning system for cyber attacks
By Kevin McCaney
The hacks this year of the Office of Personnel Management databases, which went on for months before being discovered, underscored the importance of being able to detect network intrusions early on. But what if you could detect them before they happen?
The Intelligence Advanced Research Projects Agency wants to find out, by using a combination of internal security controls with external indicators to generate automated warnings of potential attacks, according to a Broad Agency Announcement. The Cyberattack Automated Unconventional Sensor Environment (CAUSE) essentially is looking to combine the kinds of monitoring (social media, search terms) used to track political trends or disease outbreaks with other "unconventional" sensors and advanced network monitoring.
IARPA points out that serious cyber attacks don't just happen "but evolve in a phased approach" that includes early stages of reconnaissance and planning, not unlike burglars "casing" a bank before carrying out a job. CAUSE will seek to identify activity in those early stages as much as possible.
The BAA doesn't get into a lot of specifics about what those unconventional sensors will be, since researchers are likely hoping vendors will bring something fresh to the table, but it does say that it will involve publicly available, lawfully obtained information. IARPA also points out that it will include "data not typically used in practice today for cybersecurity (at least not in the way the data was originally intended) and may come from non-typical disciplines that can be applied to the cybersecurity domain."
A key to the project, as with other attempts to sift through public information, is data fusion, in this case combining data from multiple platforms, both inside and outside the enterprise. Among the things IARPA is not looking for are systems that identify specific individuals or forecasts about insider threats; those and some other features are considered outside the scope of CAUSE.
IARPA said CAUSE will be a three-and-a-half-year program in three phases, the first lasting 18 months, followed by two 12-month phases. Phase 1 will focus on identifying predictive threat signals, creating new sensors and generating cyber attack warnings. Phase 3 will work on enhancements to and integration of the various internal and external sensors. And in Phase 3, IARPA will look for the ability to integrate the systems within the organization, along with further improvements in sensors and data fusion. Work is expected to start in February 2016.
Kevin McCaney is a former editor of Defense Systems and GCN.


The Overseas Development Institute, a UK think-tank devoted to development and humanitarian issues, has developed a tool to help agribusiness investors gauge the degree of tenure-rights risk within Africa's developing markets.
Using a 0-100 classification of environmental, social and governance conditions within specific locations derived from geospatial data and provided by Landscope, a non-profit organization, the Tenure Risk Tool (TRT) allows users to input estimates of a project's expected capital and operating expenditures, as well as revenue, along with a discount rate at which the investor plans to calculate net present value.
The TRT then calculates the likely impact of delays on the timing of revenues and value of a project, providing separate projections of minimum, median and maximum potential losses due to tenure-risk related delays in specific locations. It also provides estimates of costs due to potential delays during the inception and operation of a project, with distinct readings for greenfield and brownfield approaches.
In a report about the tool, which was developed in partnership with TMP Systems, ODI described the risk of dispute between investors and locals over land or natural resource claims as "endemic" in emerging markets. Such risks, according to the report, are becoming more pronounced due to growing pressure on land and easier access to communication tools, among other factors.
Strategies to avoid such risks – including conducting land entitlement processes or establishing grievance mechanisms – are cost effective when compared with the potential tenure disputes, the report said, but often hard to justify internally.
"Investors do not have a way of putting a figure on the financial impact that tenure disputes can have on their operations, making it difficult to make the business case for implementing mitigation strategies into their investment process," the report's authors wrote.
In addition to helping decide where to invest, information provided by the TRT can also help investors shape their approach to agribusiness investment within a specific region, country or crop.
"It may well be possible to pilot a land investment with a less capital-intensive crop with a shorter production cycle before moving into a crop that would be much harder hit by tenure-related delays," according to the report, which was based on interviews with nearly 80 companies and a database of more than 600 tenure-related disputes across industries.
Anna Locke, head of ODI's program on agricultural development and policy, told Agri Investor that although land tenure has not been as prominent an issue on the ESG agenda as environmental damage or climate change risk, she expects it will become a more pressing concern of LPs in the future.
To illustrate, Locke highlighted a 2018 USAID survey in which 58 percent of respondents reported that land tenure risks have increased "significantly" or "very significantly" over the past five years.
She said work as an agricultural advisor to the government of Mozambique in the years immediately following the economic crisis exposed Locke to a flood of investor interest in African agriculture that included hedge funds, pension funds and venture capital firms.
Tenure risk is often not a focus for such groups, Locke said, adding that investors tend to take government guarantees that a specific property is available for sale at face value.
ODI's development policy work focuses on programs and business models benefiting investors and the developing world communities where they invest. Its supporters include the UK's Department for International Development, philanthropies like the Gates Foundation and Omidyar Network and government-linked DFIs from Germany and Sweden, among others, according to Locke.


One of the most spectacular failings of this Brexiter government has been its inability and unwillingness to understand – even in the slightest – how our European partners (NB: not 'opponents' or 'enemies') see us. Which partly explains why the negotiations – or rather, capitulation – is going as swimmingly as it is.
Having read a good amount of European press on Brexit, I think I can make a fair assessment of what Europeans think of us Brits at the moment: clueless, arrogant, xenophobic, selfish and whiny.
There is a well-known sketch from a German political satire show which portrays the Brits as always requiring an Extrawurst. This literally translates to 'extra sausage' – a concept used in German to convey when someone constantly demands special treatment. We were already known for always wanting an Extrawurst when we were in the EU: no Schengen, no Euro, opt-outs for this, opt-outs for that.
But now we still want Extrawurst as we are leaving the EU: we don't want your citizens here, we want out of the Single Market and Customs Union, we don't want your court having jurisdiction here, you cannot tell us what to do ever again about anything, but we'd please like to stay in relevant bodies governing aviation and medicines and also please access to your single market for industries we want, like finance and automotives. But only the stuff we choose, thankyouverymuch, opt-ins for this and opt-ins for that. And ideally we will stop the EU from passing any laws we don't like, even when we're not in it anymore.
This behaviour has led to the coining of the phrase "ewige Extrawurst" – endless extra sausage. Basically, the Europeans are fed up with us thinking we deserve this special treatment because we are somehow better than them. They are fed up with us freeloading off the back of the EU and not pulling our weight, of wanting endless opt-outs or opt-ins and never being satisfied.
Brexit provides them with an opportunity to finally be rid of our constant demands for Extrawurst, and they will use it. They will compromise to the extent that it serves Europe's interests – they want to continue trading with us too and will therefore draw up a good free trade agreement – but that's it. There will be no cherry-picking, no more englische Kirschen.
I find that these perceptions are most openly and honestly expressed in the political cartoons published in European newspapers. There is the pre-referendum drawing of European leaders in a rowing boat, with Merkel, Hollande and Junker sweating furiously to keep Europe afloat, while Cameron sits at the helm of the boat in a sunlounger, telling them they need to put in more effort for him to stay.
The traditionally Anglophile Dutch have been particularly scathing in their cartoons, one shows May and Corbyn sitting in a little boat labelled 'Brexit' on a rough sea, both vomiting profusely, captioned 'Britannia Rules the Waves.' A recent one showed May being hit in the face with a tub of Unilever butter, the pack reading 'Greetings from Holland'.
Other common Brexit cartoon themes in Europe revolve around the fact that the government does not know what it wants and is bitterly divided, and others show Britain engaging in an unbelievable act of self-harm: jumping out of a plane without the parachute the EU is offering, or cutting off various limbs in a show of misguided defiance.
That is how we are viewed now. As closed and xenophobic. As a poor team player. As arrogant and selfish. As haughty. As unreasonable. As uncooperative. As always demanding an Extrawurst. How incredibly sad.


text:
Q: How to create a mp3 player?
Possible Duplicate:
Building a simple mp3 music player

I want to create simplest mp3 player in C or C++.
What function or API do I have to use ?

A: If you just want to write a C or C++ program which plays an mp3 file, you might want to look here: How to play MP3 files in C?.
If you are looking to write something more complex (say a full GUI application to select and play mp3s, including elements to play/pause, jump to a part of the song (and see what part is playing), and view song metadata, etc) than the best advice I can give you is to jump right into your program and start coding. The number of things that would need to be covered to give you an adequate response to a general question are very vast, and we don't know anything about what you are trying to do, what your experience is, or what you might have problems with.
If you jump into it and then ask questions if you get stuck on a part of it, it will overall be a lot more helpful for everyone.

A: Let me introduce you FMod. It is free for non-commercial use and supports tons of music and sound formats, not only mp3. You should take a look after it for sure! It is so great as simple for use i think.