From a18cf4849386123f61d5da2ded7a53f027734ff7 Mon Sep 17 00:00:00 2001 From: Graham McIntire Date: Tue, 31 Mar 2026 10:47:39 -0500 Subject: [PATCH] Add regional analysis to algo.md, update site title to NTMS - Document Finding 11: regional QSO performance by Maidenhead field - Explain why regional weight adjustments are not justified - Fix algo.md table formatting (blank lines before tables for Earmark) - Change page title from Phoenix Framework to North Texas Microwave Society --- algo.md | 43 +++++++++++++++++++ .../components/layouts/root.html.heex | 2 +- 2 files changed, 44 insertions(+), 1 deletion(-) diff --git a/algo.md b/algo.md index a346ca26..67ff07fd 100644 --- a/algo.md +++ b/algo.md @@ -275,6 +275,49 @@ Monthly ducting probability from 3,901 soundings: The CW advantage (~7 dB bandwidth: 10*log10(2700/500)) translates to 24% longer average distances. Scoring tier range estimates should be qualified by mode. One confirmed 710 km rainscatter contact at 24 GHz (CW mode). +### Finding 11: Regional Performance Varies but Is Not Algorithm-Correctable + +10 GHz QSO distances by Maidenhead field (N≥20): + +| Field | Region | QSOs | Avg km | P90 km | Max km | +|-------|--------|------|--------|--------|--------| +| FM | Mid-Atlantic (DC/VA/MD) | 664 | 321 | 606 | 1041 | +| EL | Florida/Gulf Coast | 32 | 231 | 460 | 1609 | +| CM | N. California | 3,935 | 224 | 411 | 1460 | +| EN | Upper Midwest (WI/MN/IL) | 18,745 | 217 | 343 | 1223 | +| FN | Northeast (NY/NE) | 20,957 | 215 | 418 | 1212 | +| DM | SoCal/Southwest | 6,314 | 203 | 365 | 1448 | +| EM | South-Central (TX/OK) | 2,204 | 146 | 272 | 1609 | +| CN | Pacific Northwest | 119 | 84 | 192 | 468 | + +At 24 GHz, the ranking shifts — dry regions outperform because absorption dominates: + +| Field | Region | QSOs | Avg km | P90 km | +|-------|--------|------|--------|--------| +| DM | SoCal/Southwest | 279 | 157 | 227 | +| CM | N. California | 318 | 129 | 221 | +| EN | Upper Midwest | 1,135 | 98 | 178 | +| FN | Northeast | 1,644 | 90 | 144 | +| EM | South-Central | 251 | 43 | 83 | + +Sounding data by region shows ducting frequency is broadly similar (52-62%), suggesting the atmosphere is not the primary driver of the 4x regional spread in QSO distances: + +| Region | Stations | Soundings | Ducting % | Avg BL Depth | +|--------|----------|-----------|-----------|-------------| +| West Coast | 17 | 634 | 61.7% | 1043m | +| Southeast/Gulf | 29 | 1,357 | 55.6% | 741m | +| Central | 37 | 1,235 | 53.6% | 990m | +| Northeast/Mid-Atl | 16 | 930 | 52.3% | 558m | + +**Why regional adjustments are NOT in the scoring model:** + +1. **Station density and operator skill dominate.** The Mid-Atlantic's top ranking correlates with a dense cluster of experienced mountaintop operators, not unique atmospheric physics. Contest results reflect who showed up and where, not just propagation. +2. **Terrain is the confound.** PNW (CN) underperforms due to Cascades blocking paths, not worse atmosphere. Terrain profiles handle this separately. +3. **The weather inputs already capture the physics.** Coastal inversions (high humidity + refractivity), dry air (low absorption at 24G), and boundary layer depth are all in the scoring factors. If the Mid-Atlantic has better ducting conditions on a given day, it scores higher naturally. +4. **Overfitting risk.** The QSO dataset is 97% Aug-Sep contests. Regional weights calibrated to contest patterns would break for non-contest conditions (winter, spring, nighttime). + +The correct approach is to let the physics-based factors (humidity, refractivity gradient, BL depth, time of day) produce regional variation organically rather than applying static multipliers. + --- ## Part 3: Band Configuration diff --git a/lib/microwaveprop_web/components/layouts/root.html.heex b/lib/microwaveprop_web/components/layouts/root.html.heex index 80e4876d..9e582bdb 100644 --- a/lib/microwaveprop_web/components/layouts/root.html.heex +++ b/lib/microwaveprop_web/components/layouts/root.html.heex @@ -4,7 +4,7 @@ - <.live_title default="Microwaveprop" suffix=" · Phoenix Framework"> + <.live_title default="North Texas Microwave Society" suffix=" · NTMS"> {assigns[:page_title]}