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Propagation Maps

github-actions[bot] edited this page Nov 18, 2025 · 2 revisions

Propagation Maps Guide

VOACAP-Style Coverage Maps with Maidenhead Grid Overlay

Overview

The Propagation Maps feature provides VOACAP-compatible signal strength and reliability predictions visualized on an interactive map with Maidenhead grid square alignment.

What You Get:

  • Reliability (REL) Maps - Circuit reliability percentage (0-100%)
  • Signal Strength (SDBW) Maps - Signal-to-noise ratio in dB
  • Maidenhead Grid Alignment - Perfect for amateur radio operators
  • Interactive Display - Click grid squares for detailed predictions
  • Mode-Specific Predictions - WSPR, FT8, CW, SSB presets
  • Space-Efficient Design - Fullscreen map interface

Features

Two Map Types

1. Reliability (REL) Maps Shows circuit reliability percentage based on signal fading statistics and required SNR threshold.

Color Scale:

  • 🔴 Red (90-100%): Excellent propagation
  • 🟠 Orange (70-90%): Good propagation
  • 🟡 Yellow (50-70%): Fair propagation
  • 🟢 Green (30-50%): Marginal propagation
  • 🔵 Blue (10-30%): Poor propagation
  • ⚪ Gray (0-10%): Unlikely propagation

2. Signal Strength (SDBW) Maps Shows signal-to-noise ratio in decibels.

Color Scale:

  • 🔴 Red (>40 dB): S9+ signals
  • 🟠 Orange (30-40 dB): S9 signals
  • 🟡 Yellow (20-30 dB): S7 signals
  • 🟢 Green (10-20 dB): S5 signals
  • 🔵 Blue (0-10 dB): S3 signals
  • ⚪ Gray (<0 dB): Weak signals

Mode Presets

Automatic configuration for common amateur radio modes:

Mode Bandwidth Required SNR VOACAP Match
WSPR 6 Hz -28 dB 3 dB/Hz ✓
FT8 50 Hz -21 dB 19 dB/Hz ✓
CW 500 Hz +6 dB 13 dB/Hz ✓
SSB 2700 Hz +10 dB 38 dB/Hz ✓

These match VOACAP's bandwidth specifications exactly for accurate predictions.

Quick Start

1. Generate Map Data

cd Dashboard
python generate_propagation_maps.py

This creates map files in Dashboard/propagation_maps/:

map_20m_SSB_1800Z.json
map_20m_FT8_1800Z.json
map_40m_FT8_0000Z.json
map_15m_FT8_1800Z.json

First Generation Time: ~5-10 minutes per map (25,000+ grid points)

2. View Maps

Option A: Via Dashboard Server

cd Dashboard
python server.py

Then open: http://localhost:8000/propagation_maps.html

Option B: Direct File Access Open Dashboard/propagation_maps.html directly in your browser.

3. Interact with Maps

Controls:

  • Band Selection: 40m, 20m, 17m, 15m, 10m
  • Mode Selection: WSPR, FT8, CW, SSB
  • Display Toggle: Reliability ↔ Signal Strength
  • Time Selection: Hourly UTC (0-23)
  • Refresh: Generate new predictions

Click any grid square for detailed popup:

Grid: FN74
Distance: 4,689 km
SNR: 26.2 dB
Reliability: 82.9%
Mode: 2F2 (2 hops)

Using Programmatically

Generate Custom Maps

from Dashboard.generate_propagation_maps import generate_propagation_map
# Your station
TX_LAT = 44.374
TX_LON = -64.300
# Generate map
map_data = generate_propagation_map(
 tx_lat=TX_LAT,
 tx_lon=TX_LON,
 frequency=14.074, # 20m FT8
 mode='FT8',
 utc_hour=18,
 month=11,
 ssn=77,
 tx_power=80.0,
 map_range_deg=60.0, # ±60° coverage
 resolution='medium' # 2° x 1° grid squares
)
# Access predictions
for pred in map_data['predictions']:
 print(f"{pred['grid']}: SNR={pred['snr_db']:.1f} dB, "
 f"REL={pred['reliability']:.1f}%")

Apply Mode Presets

from src.dvoacap.prediction_engine import PredictionEngine
from Dashboard.mode_presets import apply_mode_preset
engine = PredictionEngine()
# Automatically configure for FT8
apply_mode_preset(engine, 'FT8')
# Now engine.params.bandwidth_hz = 50
# And engine.params.required_snr = -21
# Or manually set
engine.params.bandwidth_hz = 2700 # SSB
engine.params.required_snr = 10 # 10 dB SNR

Map Data Format

{
 "metadata": {
 "generated": "2025年11月17日T23:30:00Z",
 "tx_location": {"lat": 44.374, "lon": -64.300},
 "frequency_mhz": 14.074,
 "mode": "FT8",
 "ssn": 77,
 "bandwidth_hz": 50,
 "required_snr": -21,
 "grid_count": 25652,
 "successful_predictions": 24891
 },
 "statistics": {
 "snr": {
 "min": -5.2,
 "max": 45.3,
 "mean": 28.7,
 "median": 30.1
 },
 "reliability": {
 "min": 12.3,
 "max": 98.7,
 "mean": 76.2,
 "median": 81.5
 }
 },
 "predictions": [
 {
 "grid": "FN74",
 "lat": 44.5,
 "lon": -64.0,
 "distance_km": 45.2,
 "snr_db": 42.1,
 "reliability": 95.3,
 "signal_dbw": -68.2,
 "loss_db": 142.5,
 "mode": "1F2",
 "hops": 1
 }
 ]
}

Performance

Map Generation

Resolution Grid Points Generation Time File Size
Coarse (field) ~1,000 1-2 min 50-100 KB
Medium (square) ~25,000 5-10 min 200-500 KB
Fine (subsquare) ~250,000 50-100 min 2-5 MB

Recommendation: Use medium resolution for most applications.

Map Display

  • Loading Time: <1 second
  • Rendering: Instant with Leaflet
  • Memory Usage: ~10 MB per map
  • Browser Support: All modern browsers

Advanced Configuration

Custom Grid Resolution

# Coarse: 10° x 5° field-level squares
map_data = generate_propagation_map(..., resolution='coarse')
# Medium: 2° x 1° square-level (default)
map_data = generate_propagation_map(..., resolution='medium')
# Fine: 5' x 2.5' subsquare-level
map_data = generate_propagation_map(..., resolution='fine')

Custom Map Range

# Local coverage (±30°)
map_data = generate_propagation_map(..., map_range_deg=30.0)
# Continental coverage (±60°)
map_data = generate_propagation_map(..., map_range_deg=60.0)
# Global coverage (±90°)
map_data = generate_propagation_map(..., map_range_deg=90.0)

Batch Generation

Generate maps for multiple scenarios:

bands = [(7.074, '40m'), (14.074, '20m'), (21.074, '15m')]
modes = ['WSPR', 'FT8', 'CW', 'SSB']
hours = [0, 6, 12, 18]
for (freq, band), mode, hour in itertools.product(bands, modes, hours):
 map_data = generate_propagation_map(
 tx_lat=TX_LAT, tx_lon=TX_LON,
 frequency=freq, mode=mode, utc_hour=hour,
 month=MONTH, ssn=SSN
 )
 # Save or process map_data

Comparison to VOACAP

Feature VOACAP DVOACAP-Python Status
REL Maps ✅ Static PNG ✅ Interactive Enhanced
SDBW Maps ✅ Static PNG ✅ Interactive Enhanced
Maidenhead Grid ❌ Not aligned ✅ Perfect alignment New
Mode Presets ❌ Manual entry ✅ Auto-config New
Bandwidth Parameter ✅ Yes ✅ Yes Fixed
Click for Details ❌ No ✅ Yes New
Export Format PDF/PNG JSON + HTML Enhanced

Integration with Dashboard

Add to Main Dashboard

Option 1: Navigation Link

<a href="propagation_maps.html" class="nav-link">
 📊 Propagation Maps
</a>

Option 2: Embedded Tab

<div class="tab-content" id="maps-tab">
 <iframe src="propagation_maps.html"
 style="width:100%;height:100%;border:none;">
 </iframe>
</div>

Option 3: Flask Route

@app.route('/maps')
def maps_page():
 return send_from_directory('Dashboard', 'propagation_maps.html')

Troubleshooting

Map Data Not Found

Error: Map data not found: map_20m_SSB_1800Z.json

Solution: Generate maps first:

cd Dashboard
python generate_propagation_maps.py

Slow Map Generation

Problem: Takes >10 minutes to generate

Solutions:

  1. Use coarse resolution for wide areas
  2. Reduce map_range_deg (e.g., 30° instead of 60°)
  3. Run overnight for large batches
  4. Cache generated maps (reuse for same conditions)

High Memory Usage

Problem: Browser uses >500 MB RAM

Solutions:

  1. Close unused tabs
  2. Reduce map_range_deg
  3. Use coarse/medium resolution
  4. Restart browser periodically

Future Enhancements

Planned features:

  1. Real-time Generation - API endpoint for on-demand maps
  2. Animation - 24-hour time-lapse playback
  3. Path Overlay - Show specific DX paths on map
  4. Contour Lines - Add MUF/FOT/LUF contours
  5. 3D Visualization - Height-coded reliability surface
  6. Export - Save maps as PNG/PDF
  7. Compare Mode - Side-by-side WSPR vs SSB

References

  • VOACAP Online: voacap.com
  • Maidenhead System: Wikipedia
  • DVOACAP Validation: See VOACAP_VALIDATION_FINDINGS.md
  • Implementation Details: See Dashboard/PROPAGATION_MAPS_README.md

Credits

  • VOACAP: Original propagation model by NTIA/ITS
  • DVOACAP: Pascal implementation by Alex Shovkoplyas (VE3NEA)
  • DVOACAP-Python: Python port with map enhancements
  • Leaflet: Interactive mapping library

Last Updated: 2025年11月18日 Status: Production Ready Tested With: 20m/40m/15m on SSB/FT8/CW/WSPR modes

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