| 摘要 |
A surveillance system for simultaneously identifying the directions and frequencies of a plurality of electromagnetic-radiation sources includes an irregular array (10) of antenna elements and employs a two-dimensional compressive receiver (14) that receives at its input ports (18) the individual element signals. Each output of the two-dimensional compressive receiver (14) is modulated in an associated modulator (20) by one signal of a composite ensemble of signals. The composite ensemble is the sum of a plurality of individual ensembles, each of which is an ensemble of signals of a frequency uniquely associated with that individual ensemble and individually modulated to favor a direction associated with that individual ensemble. The results are added together in summation circuit 22 and applied to a Bragg cell (24), which segregates the results of modulation by the individual ensembles. When a pulse occurs at one of the output ports (28) of the Bragg cell (24), the time of occurrence of that pulse within the output sweep of the two-dimensional compressive receiver (14) indicates the temporal frequency of the antenna signal that gave rise to it, while the output port on which the pulse occurs is an indication of the direction of the source.
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