Mix tasks that call app.start were also booting Oban's cron scheduler,
causing PropagationGridWorker and other cron jobs to fire during
backfills. Add Oban.pause_all_queues(Oban) immediately after app.start
in every mix task that only needs Repo access.
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).
Inversion detection module (Propagation.Inversion):
- find_inversion_top/1 walks the native profile to locate the first
temperature inversion (surface-based or elevated)
- bulk_richardson/3 computes the Richardson number across the
inversion layer (Ri < 0.25 = turbulent, > 1 = laminar/good)
- shear_magnitude/3 computes the wind shear vector magnitude
- potential_temperature/2 for θ = T*(P0/P)^0.286
Theta-e module (Weather.ThetaE):
- Bolton (1980) equivalent potential temperature
- dewpoint_from_spfh/2 via Magnus-Tetens inversion
- theta_e_jump/3 for the thermodynamic decoupling metric
mix hrrr_native_derive_fields populates inversion_top_m,
bulk_richardson, theta_e_jump_k, and shear_at_top_ms on existing
hrrr_native_profiles rows.
First real data: 2022-08-20 12Z TX profile shows inversion at
186 m, Ri = 0.16 (turbulent), θ_e jump = 0.33 K — consistent with
marginal propagation conditions at that hour.
