Universal Stabilized Platform for Hyperspectral Sensors

Airborne hyperspectral sensors of the pushbroom and whiskbroom type build up spatial imagery one strip (pushbroom) or one pixel (whiskbroom) at the time. As the platform undergoes attitude changes in flight (yaw, pitch, roll), the line of sight moves around and the collected imagery suffers from geometrical distortions. This affects every instrument built and operated that is subject to atmospheric disturbances. The distorted images can not be well geo-registered for incorporation into a GIS data base. Available solutions are (i) software correction to the images based on flight attitude data collected using a strap down gyro system, or (ii) mounting the sensor on a stabilized platform. The former is a difficult and unreliable process, while the latter is a very expensive solution, impractical with many small air crafts. Examples for the former include the AVIRIS low altitude flights that require a significant effort after which the data are still not completely registered. OKSI proposes a much less expensive solution in which the sensor is strapped to the aircraft but to compensate for the aircraft motion the sensor line of sight is continuously stirred, using a closed loop control system. Since the mass to be controlled is very low, the actuation and control system will be simple and relatively inexpensive. Such line of sight stabilizer can be adapted to other hyperspectral sensors with a relative small effort.