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Target Discrimination/Cl1assification Radar.

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Final rept. 1 Aug 92-31 Jul 95,

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The purpose of this study was to develop a signal processing scheme that would combine the separate research efforts of low probability of intercept signaling, low altitude low observable target tracking, and non-cooperative target recognition into a single research effort. The end result of this fusion is a new radar design concept designated adaptive FSKPSK signaling. An adaptive FSKPSK radar system makes use of matched FSKPSK signals in conjunction with a gradient descent adaptive signal design algorithm. Matched FSKPSK signals are ultra wideband pseudorandom multiple frequency bi-phase modulated signal sequences that have spectral content specifically matched to the target under track. This use of target-specific information in the design of radar signals is the salient point of this research effort. It allows for more efficient use of signal power and results in a performance improvement over existing radar technologies that are matched to the transmit signal only. Since the spectral content of the target is not known a priori, the target range profile must be learned by the radar. This matching of the signal to the target is accomplished through the use of an iterative adaptive algorithm that is based on gradient descent. Once the radar has adapted to the target learned the target, the range profile of the target is known and target identification can take place based on the learned range profile. Therefore, an adaptive FSKPSK radar system can be thought of as a learning system as opposed to a measurement system. In other words, the radar measurement is improved as a result of the learning process. The pseudorandom sequence structure of the matched FSKPSK signal, along with its high time-band-width product, makes the radar inherently difficult to detect.

Subject Categories:

  • Radar Countermeasures
  • Active and Passive Radar Detection and Equipment

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