Com Dev International, Inc.

Exactearth Ltd.

Weiguo Chen

Robert C Peach

Arunas Gabriel Macikunas

A satellite system for detecting radio frequency signals from space including at least two sensors, a processing unit and at least one receiver. Each sensor receives a plurality of radio frequency signals containing messages and outputs a sensor signal that is representative of the plurality of radio frequency signals. The processing unit selects a predetermined number of mathematical combinations of the sensor signals and combines the sensor signals into the predetermined number of mathematical combinations to produce a plurality of zone signals. The characteristics of each zone signal are undefined at the time the predetermined number of mathematical combinations is selected. The receiver extracts the messages contained in the zone signals.

Systems and methods for segmenting a satellite field of view for detecting radio frequency signals

A method of extracting automatic identification system (AIS) message segments from AIS signals received by a satellite. The method includes: (a) receiving AIS signals from satellite antennas; (b) generating multiple versions of the AIS signals; (c) extracting message segments contained within each of the AIS signals using one or more AIS receivers; (d) sorting the message segments by time; and (e) deleting any duplicate message segments. Multiple versions of the AIS signals may be generated by one or more of the following methods: (i) processing the AIS signals multiple times, each time with different AIS receiver parameter settings; (ii) splitting each signal into multiple signals and filtering each of the multiple signals separately; (iii) receiving multiple AIS signals and combining them with different phases and amplitudes to produce a plurality of combined AIS signals; and (iv) removing extracted message segments from the received AIS signals and reprocessing the modified AIS signals.

Systems and methods for decoding automatic identification system signals

Embodiments disclosed herein relate generally to digital transponders. In one broad aspect, there is provided a digital transponder comprising: (a) an analog to digital converter configured to receive a real analog wideband multi-carrier signal and generate a real digital wideband multi-carrier signal from the real analog wideband multi-carrier signal, the real analog wideband multi-carrier signal spans M element channels, M being an integer greater than or equal to one; (b) a channelizer configured to channelize the real digital wideband multi-carrier signal intoM channelized digital signals, theM channelized digital signals comprising M pairs of channelized digital signals, each pair of channelized digital signals comprising a primary channelized digital signal and a secondary channelized digital signal, the secondary channelized digital signal being an image of the primary channelized digital signal; (c) a switch matrix and signal construction module configured to generate a plurality of intermediate signals from only the primary channelized digital signals, the plurality of intermediate signals comprising pairs of intermediate signals, each pair comprising a primary intermediate signal and a secondary intermediate signal, the secondary intermediate signal being an image of the primary intermediate signal; (d) at least one synthesizer, the at least one synthesizer configured to combine at least one pair of intermediate signals to generate a real digital output signal; and (e) at least one digital to analog converter, the at least one digital to analog converter configured to convert the real digital output signal to an analog output signal.

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Cambridge, Canada

Weiguo Chen