Both bands share the physics of low microwave: humidity and refractivity
gradient build ducts the same way, and rain + gas absorption are
effectively zero at VHF/UHF. humidity_effect is :beneficial, rain_k /
rain_alpha are (0, 1), and o2_db_km / h2o_coeff are 0.
Range estimates reflect tropo reality: 2m ducts can reach 2500+ km
under exceptional conditions (e.g. documented Hawaii ↔ California
openings), 70cm a bit less. The seasonal base matches the low-microwave
summer-peak curve.
These configs do NOT capture sporadic-E, meteor scatter, or aurora —
those need ionospheric data (GIRO ionosondes, NOAA SWPC) we don't yet
ingest. The scoring on these bands is therefore "tropo-only" and will
underestimate openings driven by ionospheric modes.
Direct queries against prod (75M HRRR profiles, 16,864 soundings, 392k
surface obs, new hrrr_native_profiles table) drive these changes:
* Reinstate shallow-BL bonus as an HPBL multiplier on the refractivity
score (1.10× <200m → 0.78× ≥2000m). The Apr 11 "shallow BL bonus
removed" conclusion was an artifact of the prior matching strategy;
with the cleaner contact↔HRRR join (n=680) the binned data goes 230 km
avg at HPBL <200m vs 100 km at ≥2000m, monotonic across all bins.
* Add 6 missing bands (142, 145, 288, 322, 403, 411 GHz) so contacts in
those bands stop being silently dropped. Coefficients extrapolate
ITU-R P.676/P.838 trends from the existing 134/241 GHz entries.
* Bump ERA5 poll timeout 10 min → 1 hour and Era5MonthBatchWorker
max_attempts 3 → 5 so CDS slowness stops discarding tiles. Also dump
the full failure body when CDS omits the message field — the prior
"ERA5 job failed: nil" was masking real error reasons in oban_jobs.
* Add scripts/recalibrate_algo.py so this analysis can be re-run any
time new data lands without manual SQL. Reads PROP_PROD_DB_URL from
.envrc, drops a Markdown report into docs/algo-reports/.
* Append a dated Part 2c to algo.md documenting the corpus expansion,
the honest accounting of historical HRRR coverage (only ~1,020 of 58k
contacts are precision-matchable), and the empty era5/rtma/climatology
tables. Update the gaseous-absorption and rain-attenuation tables to
include the new bands.
Test suite: 1,335 tests, 0 failures.
New BandConfig entries for 902, 1296, 2304, 3456, 5760 MHz:
- All beneficial humidity effect (like 10 GHz)
- Near-zero gaseous absorption and rain attenuation
- Ranges: 902 MHz typical 400 km, 5760 MHz typical 220 km
- Same seasonal curves as 10 GHz (ducting-driven)
BandConfig.band_options/0 generates dropdown options from configs.
All pages (path, rover, submit) use centralized band_options instead
of hardcoded lists. Map page already used BandConfig.all_bands().
10 GHz remains the default on all pages.
Score time-of-day per grid point using longitude/15 solar offset instead of
hardcoded CST/CDT. Add PWAT as 10th scoring factor. Refine pressure thresholds.
Update ML model and training pipeline to use local solar time.
Previous thresholds (-500 to -60) were calibrated for radiosonde data.
HRRR profiles have coarser vertical resolution, with gradients clustering
between -40 and -130 N/km (median -70). Nearly all grid points were
falling through to the default score of 42, wasting the refractivity
factor. New thresholds (-200 to -40) spread across HRRR percentiles.
Single source of truth for all scoring parameters: weights, thresholds,
seasonal tables, and per-band coefficients for 8 microwave bands
(10G through 241G). Includes ITU-R P.838-3 rain attenuation
coefficients, humidity effects, refractivity scoring thresholds,
and sunrise/tier definitions.
