Systems and methods for detecting targets using pulse-compressed radar
signals are disclosed. In one application, relatively small targets that
are masked by the time-sidelobes of a larger target's return signal can
be detected. The methods include a signal expansion type algorithm that
is used to process the pulse-compressed return signal. Specifically, a
generalized Fourier expansion expression having a summation of PSF terms
is used to expand the pulse-compressed signal. Each term represents a
respective target and includes a point spread function and a complex
coefficient. The signal expansion procedure can be used to determine a
set of optimum complex coefficients, with one coefficient for each range
bin. Doppler frequency can be used together with range to optimize the
complex coefficients. Next, targets are detected by analyzing each range
bin to determine whether the corresponding complex coefficient has an
absolute magnitude greater than a pre-determined threshold.