Abstract: GEO satellites and other space objects are studied in daylight, twilight and at night using IR cameras in clusters of no more than three with programs for pointing the instruments at known locations of the GEO objects and satellites and receiving weak near IR signals. Detection instruments have minimal optical surfaces and simple optical paths directing IR through Kshort and combined Kshort and H near IR band filters in cryogenic assemblies. Large focal ratios and large apertures reduce the effect of sky brightness, lower noise and improve the target signal, increasing the noise to signal ratio. Sky background noise is reduced by co-adding hundreds of pixels, allowing for the faint IR signal integration of one second or more. Results are read after integration.

Abstract: A single focal plane integrated circuit hybrid replaces multiple focal plane circuits and associated off-focal plane signal processing electronics. A dual function, dual color focal plane PSD sensor chip assembly includes a PSD array, a traditional pixelized camera array, a signal processing chip, and flip-chip interconnects and wirebond pads to support electronics on the signal processing chip. The camera array is made of a material sensitive to wavelengths longer than the PSD array material is sensitive to. The PSD array is disposed in the same substrate as the camera array. The PSD array tracks object locations and directs the camera array to window and zoom while capturing images. Inherent registration of PSD cells to the pixelized camera array makes responsivity map testing and spatial calibration unnecessary. Reduction in power dissipation is achieved by powering on the camera array only when the PSD detects a change in scene.