text: * ACE observations. The [http://www.ace.uwaterloo.ca/ Atmospheric Chemistry Experiment] (ACE) satellite, also known as SCISAT-1, is a Canadian satellite that makes measurements of the Earth's atmosphere and follows in heritage of ATMOS.
  * Aura observations. [http://aura.gsfc.nasa.gov/ Aura] flies in formation with the NASA EOS "A Train," a collection of several other satellites (Aqua, CALIPSO, CloudSat and the French PARASOL). Aura carries four instruments for studies of atmospheric chemistry: MLS, HIRDLS, TES and OMI.
  * ILAS observations. [https://web.archive.org/web/20070205195349/http://www-ilas.nies.go.jp/index.html ILAS] (Improved Limb Atmospheric Spectrometer) developed by MOE (the Ministry of the Environment) (formerly EA - Environment Agency of Japan) is boarded on ADEOS (Advanced Earth Observing Satellite). On August 17, 1996, ADEOS was launched by the H-II rocket from the Tanegashima Space Center of Japan (ADEOS was renamed as "MIDORI") and stopped its operation on June 30, 1997. Data obtained by ILAS are processed, archived, and distributed by NIES (National Institute for Environmental Studies).
  * POAM observations. The [https://web.archive.org/web/20070301180400/http://wvms.nrl.navy.mil/POAM/poam.html Polar Ozone and Aerosol Measurement] II (POAM II) instrument was developed by the Naval Research Laboratory (NRL) to measure the vertical distribution of atmospheric ozone, water vapor, nitrogen dioxide, aerosol extinction, and temperature. POAM II measures solar extinction in nine narrow band channels, covering the spectral range from approximately 350 to 1060 nm.
  * Sulfate aerosol observations from SAGE and HALOE. The SAGE II (Stratospheric Aerosol and Gas Experiment II) sensor was launched into a 57 degree inclination orbit aboard the Earth Radiation Budget Satellite (ERBS) in October 1984. During each sunrise and sunset encountered by the orbiting spacecraft, the instrument uses the solar occultation technique to measure attenuated solar radiation through the Earth's limb in seven channels centered at wavelengths ranging from 0.385 to 1.02 micrometers. The retrieval of stratospheric aerosol size distributions based on HALOE multi-wavelength particle extinction measurements was described by Hervig et al. [1998].  That approach yields unimodal lognormal size distributions,  which describe the aerosol concentration versus radius using three parameters:  total aerosol concentration,  median radius,  and distribution width. This [https://web.archive.org/web/20061208105210/http://haloedata.larc.nasa.gov/home/index.php?p=noframe_home.html site] offers results based on the Hervig et al. [1998] technique,  with one exception.  The retrieval results reported here are based on sulfate refractive indices for 215 K,  where Hervig et al.  [1998] used room temperature indices adjusted to stratospheric temperatures using the Lorentz-Lorenz rule.  Size distributions were only retrieved at altitudes above tropospheric cloud tops. Clouds were identified using techniques described by Hervig and McHugh [1999].  The HALOE size distributions are offered in NetCDF files containing data for a single year.  The results are reported on a uniform altitude grid ranging from 6 to 33 km at 0.3 km spacing.  The native HALOE altitude spacing is 0.3 km,  so this interpolation has little or no effect on the data.  The files report profile data including: altitude, pressure, temperature, aerosol concentration, median radius, distribution width, aerosol composition. Aerosol surface area and volume densities can be easily calculated from the size distribution parameters using the relationships given [http://gwest.gats-inc.com/haloe_aerosols/HALOE_size_distribution_data.html here].
  * Upper Atmosphere Research Satellite (UARS) observations. Data from the UARS is available from the [https://web.archive.org/web/20030210093521/http://daac.gsfc.nasa.gov/data/ GES Distributed Active Archive Center] (DAAC). The UARS satellite was launched in 1991 by the Space Shuttle Discovery. It is  long,  in diameter, weighs 13,000 pounds, and carries 10 instruments. UARS orbits at an altitude of  with an orbital inclination of 57 degrees. UARS measured ozone and chemical compounds found in the ozone layer which affect ozone chemistry and processes. UARS also measured winds and temperatures in the stratosphere as well as the energy input from the Sun. Together, these helped define the role of the upper atmosphere in climate and climate variability.