The use of airborne camera systems is known in the art. Such systems are used for aerial mapping, monitoring of natural resources, reconnaissance, and other activities. Although some of these systems are used in orbiting satellites, they are also used in airplanes that are especially equipped with stable rack arrangements to hold the cameras to obtain images that are as clear and detailed as possible.
One problem that exists with such camera systems is system downtime. It is costly and time consuming to be prevented from operating an airborne system because one component malfunctions. This is especially true if a malfunction occurs while the system is in the air. Not only is the planned activity curtailed, but the operating and personnel costs are increased due to the necessity to repeat the curtailed operation(s). Moreover, equipment repair often necessitates disassembly, shipment to the OEM (original equipment manufacturer) for repair, and recalibration once a new or repaired component is finally made available to the system operator.
One especially vulnerable component is the camera shutter used in aerial photography systems. While some camera components, such as lenses and the image data receiver are usually inactive, the camera shutter opens and closes repeatedly to expose the image receiver to incoming light. In some contemporary systems, fifty or one hundred thousand exposures can be made over the course of a twelve month period, often in extremely rapid succession. Shutters comprise several mechanical elements such as the motors and bearings that move the shutter over the aperture. Because these elements are subjected to rapid and repeated movement, they tend to wear down over time leading to shutter failure. Such failure often occurs in mid-operation as there is ordinarily no method of determining beforehand when shutter components are about to fail. This leads not only to a waste of time and resources caused by prematurely discontinuing an operation, but also extends downtime originating from removing the camera, shipping it to the OEM or a repair center, shipping the repaired camera back, and calibrating the camera to the whole system.
What is needed then is a shutter apparatus constructed so as to be easily replaceable during operation without the necessity of prematurely discontinuing the current operation and extended downtime while a shutter or camera is shipped offsite for repair and recalibrated to coordinate with an entire system.