Retro-Geo Spinning Satellite Utilizing Time Delay Integration (TDI) for Geosynchronous Surveillance

Geosynchronous surveillance is conducted by injecting one or more observer satellites into a retro sub or super geosynchronous orbit at approximately zero inclination. The observer satellite spins about an approximately North-South axis in an Earth frame of reference to sweep a sensor's FOV around the geobelt. Sensor time delay integration (TDI) is synchronized to the observer satellite's spin-rate and possibly the sum of the spin-rate and the target inertial LOS rate to realize longer integration times. This approach facilitates faster scans of the entire geobelt, more timely updates of the catalog of tracked objects and resolution of small and closely spaced objects. An inexpensive small-aperture body-fixed visible sensor may be used.