Radar signals are generally characterised
by repetitive patterns in time. An ESM receiver
must intercept and identify several interleaved
radar signals. Time-of-arrival (TOA) deinterleaving
is employed in ESM processing to identify
and extract the pulses of each radar signal. This
task is extremely processor intensive and new
techniques are required to operate on complex
signals in high pulse densities. A new algorithm
employing novel techniques is presented for fast,
accurate deinterleaving of several repetitive
signals. A cumulative TOA difference histogram
gives an indication of probable pulse repetition
intervals (PRIs) with a minimum number of computations.
Validation and identification is given
by searching for a sequence of these pulse intervals.
The technique presented is less sensitive to
interfering pulses and more robust to missed
pulses than conventional published techniques.
Weighting is used to enhance detection of
sequences and a three-pulse priming sequence dramatically
reduces unsuccessful searches. By
employing a learning process, the efficiency is
increased still further. The application of this algorithm
to agile PRI signals is shown.
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