Compare prop and rel charts with DVOACAP results

[skyelaird]

CRITICAL FINDING:
DVOACAP predicts 0-1.2% reliability when VOACAP shows 20-100% reliability, despite both showing similar strong SNR (28-45 dB). This is a 50-100x error.

Analysis Details:

• Compared DVOACAP predictions to VOACAP reference charts (REL and SDBW)
• Test scenario: FN74ui 14.100 MHz, 1800 UTC, SSN 81
• SNR predictions: GOOD (within ±5 dB)
• Path loss: GOOD (137-156 dB vs expected 135-160 dB)
• Reliability: BROKEN (0-1% vs expected 20-100%)

The system predicts "unlikely propagation" when it should predict "excellent propagation" - making DVOACAP unusable for operational planning.

Files added:

• VOACAP_COMPARISON_ANALYSIS.md - Full technical analysis
• compare_voacap_charts.py - Comparison test script
• debug_14mhz_issue.py - Debug script for 14 MHz

Related to known issues in VALIDATION_IMPROVEMENT_ANALYSIS.md

Description

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Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Performance improvement
• Code refactoring
• Test coverage improvement

Related Issues

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• Change 2
• Change 3

Testing

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Test Results

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python -m pytest tests/

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python test_voacap_reference.py

• All existing tests pass
• New tests added for new functionality
• Validation pass rate maintained or improved
• No performance regression

Validation Checklist

• Code follows PEP 8 style guidelines
• Docstrings added/updated for public functions
• Type hints added where appropriate
• Comments added for complex logic
• Documentation updated (README, USAGE, etc.)
• CHANGELOG.md updated
• No new warnings or errors introduced

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• Code quality is acceptable
• Tests are comprehensive
• Documentation is clear
• Validation results are acceptable
• No security issues introduced
• Backward compatibility maintained (or breaking changes justified)