prop/test
Graham McIntire 82bf248ab7 Phase 4: Ray-traced duct geometry
Duct module (Propagation.Duct):
- refractivity_profile/1: ITU-R P.453 N at each native level
- m_profile/1: modified refractivity M = N + 157*h(km)
- detect_ducts/1: find contiguous regions where dM/dh < 0, returning
  base/top height, thickness, and M-deficit per duct
- min_trapped_frequency_ghz/1: waveguide approximation (Bean & Dutton)
  for the minimum frequency a duct of given geometry can trap
- analyze/1: full pipeline from native profile to duct list + best
  trapped frequency across all ducts

Derive task updated to also compute ducts JSONB and best_duct_band_ghz
alongside the Phase 2 turbulence fields.

Backtest features: duct_thickness, best_duct_freq, duct_usable_10ghz,
duct_usable_24ghz, duct_usable_47ghz.

Real-data validation: 2022-08-20 12Z TX profile shows 0 ducts (M
increases monotonically) — correct for a well-mixed boundary layer
on a turbulent August afternoon (Ri=0.16).
2026-04-10 08:31:16 -05:00
..
microwaveprop Phase 4: Ray-traced duct geometry 2026-04-10 08:31:16 -05:00
microwaveprop_web Show submitter callsign on the contacts index 2026-04-09 14:02:30 -05:00
mix/tasks fix enrichment 2026-04-02 15:30:41 -05:00
support Beacon height in feet, auto-fill lat/lon from grid 2026-04-08 12:55:10 -05:00
test_helper.exs Exclude slow GRIB2 fixture tests by default (81s -> 16s) 2026-03-31 10:00:13 -05:00