Higher-order motion compensation for passive radar processing

Evaluate and implement Doppler-rate compensation and the Keystone transform to mitigate higher-order Doppler and range migration caused by residual mismatch between TLE-based motion compensation and true target dynamics, thereby improving coherent-integration sensitivity in InteRFeX passive-radar observations.

Background

The InteRFeX processing framework uses TLE-derived motion compensation and estimates residual bistatic range and range-rate errors through the cross-ambiguity function. In the reported 1-second coherent processing intervals, the range-rate deviations exhibit step-like changes because the estimated Doppler crosses discrete resolution-bin boundaries.

The paper attributes these residual offsets partly to incomplete compensation of higher-order delay and Doppler migration over each coherent processing interval. It notes that prior MWA studies used Doppler-rate compensation and the Keystone transform to mitigate Doppler and range walk, respectively, but the implementation and experimental evaluation of these techniques remain unresolved in the InteRFeX system.

References

The implementation and evaluation of these higher-order motion-compensation techniques are left for future work.

— First Experimental Results of Space Object Detection Using the InteRFeX Array  (2610.13537 - Ahuja et al., 9 Oct 2026) in Section 3, Experimental Results and Discussion, subsection “Cross-Ambiguity Function Analysis,” discussion of Fig. 7