Adaptive Doppler Estimation for Random PRI Staggering With Clutter Cancellation

The combination of clutter cancellation and adaptive Doppler estimation are examined in the context of random pulse repetition interval (PRI) staggering, which permits a greatly expanded unambiguous Doppler span, albeit at the cost of higher sidelobes. It is shown that estimation of movers otherwise masked by clutter or the sidelobes of other larger movers can be uncovered by this combination, with adaptive estimation being particularly useful at suppressing the attendant increase in sidelobes. Using the re-iterative super-resolution (RISR) method as a representative method for adaptive estimation (a variety exists), the efficacy of this combination is demonstrated using both simulated data and open-air measurements. A clairvoyant form of signal-to-interference-plus-noise ratio (SINR) is also used to assess analytically the behavior observed in simulation, particularly the loss trade-space between straddling and super-resolution.