radar-signal-processing

name: radar-signal-processing description: Parse raw radar I/Q captures (CW or FMCW mmWave) and produce a cleaned 1-D slow-time signal ready for motion or vital-signs analysis. Use when Claude needs to read interleaved I/Q binary, do a Range FFT on FMCW chirps, remove static clutter, pick a subject range bin, extract phase with unwrapping, or debug why a radar pipeline is returning garbage. Not for pulse/UWB range gating, MIMO beamforming, or Doppler-only gesture radar.

Radar Signal Processing

Get from a raw binary I/Q capture to a clean 1-D phase trace that downstream vital-signs / motion analysis can consume.

Pipeline (do every step in order)

1. Parse binary I/Q to complex samples. Use the JSON/YAML sidecar to determine format — never assume. See references/iq-formats.md.
2. (FMCW only) Range FFT across fast time → 2-D range matrix. CW skips this step.
3. Remove static clutter. Subtract the temporal mean:
   • CW: iq -= iq.mean()
   • FMCW: R -= R.mean(axis=0, keepdims=True) on the range matrix
4. (FMCW only) Pick the subject range bin. See references/range-bin.md.
5. Extract phase with unwrap:

   phase = np.unwrap(np.angle(iq_or_bin))
   phase -= phase.mean()
   

6. If fs >= 500 Hz and downstream needs sub-Hz filtering, decimate first:

   from scipy.signal import decimate
   phase_ds = decimate(phase, q=int(fs/50), ftype='iir', zero_phase=True)
   fs_new = fs / int(fs/50)   # ~50 Hz target
   

Critical rules

When things go wrong

If the output is garbage, walk through references/debugging.md in order — it's fast and catches most ingestion/SNR bugs.

Not in scope

Pulse/UWB time-of-flight, MIMO angle-of-arrival, Doppler-only gesture radar.