Signal Reflection (KrakenSDR Multi-Beam)
Concept
Bistatic illumination-reflection analysis on a KrakenSDR. A small acquisition node does nothing but capture coherent IQ across four channels and stream it to a workstation; all DSP — cross-ambiguity, beamforming, track formation, visualisation — runs on the more capable host. The split keeps the acquisition node electrically quiet and lets the processing side scale independently.
Four surveillance beams run in parallel with independent Range-Doppler displays, per-beam configuration of the illuminator of opportunity (FM broadcast, DAB+, DVB-T), and a confirmed-track lifecycle that requires M-of-N detections before a track is promoted from tentative to confirmed.
Architecture
4-channel coherent IQ"] ACQ["Acquisition Node
capture and stream only"] NET["UDP Stream
IQ to workstation"] CAF["Cross-Ambiguity (CAF)
per beam · 100 ms coherent integration"] BF["Beamforming
4 surveillance beams in parallel"] TRK["Track Lifecycle
tentative → confirmed (M-of-N)"] DISP["Range-Doppler Display
per beam, per illuminator"] SDR --> ACQ ACQ --> NET NET --> CAF CAF --> BF BF --> TRK TRK --> DISP
The 100 ms coherent integration time is the dominant cost in the latency budget — the FFT inside the cross-ambiguity computation accounts for most of the per-beam wall time. Beam parallelism is across CPU cores, not across SDRs; the four beams share one coherent capture, not four independent radios.