A radar twin with no Doppler folding certifies an ego-velocity estimator at every speed: what does the folding sensor do to it, and when can it be unfolded?

What it found

Real radar radial speeds wrap modulo 2v_u (v_u=10 m/s); the twin’s do not. The twin-tuned least-squares ego-speed estimator has RMSE 0.022 m/s in the twin and on the real sensor up to 9.5 m/s, then 0.18 (9.8), 1.9 (10) and 14.9 m/s (12). Its large-n bias is exact in closed form (−14.94 at 12 m/s, simulated −14.92) and saturates at −D, D=2v_uΣc/Σc², once every target is one fold off. A wrapped-cost grid search restores the twin’s accuracy to 60 m/s with no mode errors, provided the azimuths are diverse: the nearest wrong speed has residual energy 4v_u²(n−(Σc)²/Σc²), independent of speed, and Φ(−√E/2σ) matches Monte Carlo (0.061 vs 0.054 at ±8°); at ±5° the search picks the wrong fold in 120 of 300 scenes. Stylised: stationary scene, known azimuths and v_u, Gaussian noise, no multi-PRF.

A figure from its own output

Paper, code and results

• README and method
• White paper
• Experiments and results
• Code
• Tests

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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.