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Automatic Burst Localization

The Auto Localize button (and the auto_localize session action) finds where the burst lives in the current crop and sets the event window, the spectral window, and the off-pulse windows in one step. It replaces the first, most error-prone part of the manual workflow; every selection it makes can still be refined by hand afterwards.

What it does

  1. Per-channel robust normalization (median/MAD computed off-event).
  2. Matched filtering of the band-integrated S/N profile over a ladder of boxcar widths to find the burst and its characteristic width.
  3. The event window is the contiguous above-noise region around the matched peak, unioned with any nearby independently detected components, with the boundaries refined at a finer smoothing scale so they land at the true signal edge rather than the matched-filter shoulder.
  4. The spectral window comes from the on-burst channel S/N over the tight event window: the contiguous significant band around the strongest channel, merged with nearby significant sub-bands (so patchy scintillation stays inside one window). If the result covers ≳95% of the usable band the burst is treated as broadband and the full band is kept.
  5. The time and frequency searches iterate — a band-limited burst is re-detected against the noise of its own sub-band, which typically raises the integrated S/N substantially — until the selections are stable.
  6. Off-pulse windows are placed on both sides of the event with a guard margin.

Reading the result

The toast (and the localization field in the action response) reports:

  • status — ok, low_sn (detected, but integrated S/N below the threshold), or no_detection (nothing crossed the detection threshold; the session selections are left unchanged).
  • detection_snr / integrated_snr — matched-filter and event-integrated S/N over the selected band.
  • band_limited — whether a sub-band was selected.
  • warning_flags — event_near_edge, wide_event, band_touches_edge, low_integrated_snr, no_offpulse_window. Treat flagged selections as candidates for manual review.

Notes

  • Localization runs at the native time resolution of the crop, regardless of the current display reduction.
  • Measurements are still computed at the session's time/frequency factors; for sub-millisecond structure work set the time factor to 1 before Compute.
  • The detection threshold defaults to S/N 6 and can be passed in the action payload (detection_snr_threshold).