Abstract: A communication system (20) utilizing a constellation (22) of satellites (24) is presented. A source ground station (52) transmits an uplink signal (34) containing source payload data (32) to a primary satellite (26) located in an orbit (70) about the Earth (56). The primary satellite (26) conveys the source payload data (32) to a secondary satellite (28) located proximate the primary satellite (26) in the orbit (70), where the source payload data (32) is baseband processed to produce destination payload data (42), which is then conveyed back to the primary satellite (26). The primary satellite (26) transmits a downlink signal (50) containing the destination payload data (42) to a destination ground station (54). The primary satellite (26) and secondary satellites are configured to expend majorities of their energy budgets in downlink transmissions and payload data processing, respectively.

Abstract: A communication system (20) utilizing a constellation (22) of satellites (24) is presented. A source ground station (52) transmits an uplink signal (34) containing source payload data (32) to a primary satellite (26) located in an orbit (70) about the Earth (56). The primary satellite (26) conveys the source payload data (32) to a secondary satellite (28) located proximate the primary satellite (26) in the orbit (70), where the source payload data (32) is baseband processed to produce destination payload data (42), which is then conveyed back to the primary satellite (26). The primary satellite (26) transmits a downlink signal (50) containing the destination payload data (42) to a destination ground station (54). The primary satellite (26) and secondary satellites are configured to expend majorities of their energy budgets in downlink transmissions and payload data processing, respectively.

Abstract: A Digital Pulse Processor (DPP) designed to accept pulsed inputs and produce digital pulse descriptor word (PDW) outputs accepts pulsed signals from three adjacent channelized inputs. The DPP then derives a measurement of pulse amplitude from the peak value in the center frequency channel. The relative peak amplitudes between channels are used to establish aa fine frequency offset. The fine frequency offset is used in conjunction with coarse frequency inputs to compute a pulse frequency estimate. An internal counter generates a time reference for time of arrival (TOA) and pulse width measurements. The TOA and pulse width measurements are based on calculations to establish three dB points on the leading and trailing edges of the pulse. This pulse characterization information is produced in real time at the optimum signal-to-noise ratio, and is independent of incoming amplitude, rise/fall time, and pulse width.