Abstract: A sensor test system is disclosed for testing the operation of infrared detector modules designed to be placed in earth orbit. The system includes an optical scene test generator (OSTG) for generating a scene representative of the earth's surface as seen from a satellite, and an object moving in relation to the earth's surface. Sensor chamber is disposed adjacent the OSTG for storing a detector module to be tested. Detector module is efficient within the sensor chamber to expose detector elements to the optical scene generated by the OSTG.

Abstract: A data processing station and a method of operating a data processing station for processing and transmitting data between first and second devices. The data processing station comprises first and second interface units. The first interface unit has a multitude of states including a remote terminal state to receive data from and to transmit data to the first device, and a bus controller state to transmit data to the second device. The first interface unit also includes a first processor to generate an interrupt signal and to transmit the interrupt signal to the second interface unit-in response to predetermined events. The second interface unit is provided to receive data from and to transmit data to the second device, and this interface unit includes a second processor adapted to generate control signals and to transmit the control signals to the first interface unit to change the state thereof at predetermined times.

Abstract: A programmable frequency identifier circuit for identifying the frequency of a contaminated signal including a digital finite impulse response filter, a zero crossing detector, a zero crossing counter, and a frequency range decoder. The filter is a programmable filter for filtering signals of the form: S(n)=S.sub.1 (n)+S.sub.2 (n)=A cos 2.pi.F.sub.1 (n)+B cos 2.pi.F.sub.2 (n) where S.sub.1 (n)=desired signal, S.sub.2 (n)=contamination, F.sub.1 =passband frequency, F.sub.2 =stopband frequency, and A,B=constants. The zero-crossing counter counts the sign changes occuring during a programmably determined frame time. The number of zero crossings occuring during the frame time is a number representing the desired frequency. The frequency range decoder is programmed with a plurality of frequency range boundaries similarly represented by a count that is based upon the programmable frame time.