Implement ITU-R P.676-13 gaseous attenuation recommendation#102
Merged
inigodelportillo merged 3 commits intomasterfrom Mar 4, 2026
Merged
Implement ITU-R P.676-13 gaseous attenuation recommendation#102inigodelportillo merged 3 commits intomasterfrom
inigodelportillo merged 3 commits intomasterfrom
Conversation
Adds full support for P.676-13, the current revision of the gaseous attenuation recommendation, superseding P.676-12. Closes #69. Key changes from P.676-12: - Annex 1: Eq. 18a (arccos) replaced by Eq. 18b (arcsin) for the ray-bending angle in the layer-by-layer slant-path integration. - Annex 2: completely restructured. Oxygen equivalent height h0 is now computed from a Part 1 coefficient table (Eq. 31: h0 = a0 + b0*T + c0*Ps + d0*rho), and water-vapour equivalent height hw uses a new analytical formula (Eq. 37, Table 4 coefficients). Implementation details: - itur/data/676/v13_lines_oxygen.txt, v13_lines_water_vapour.txt: spectroscopic line data (Tables 1 & 2, identical to P.676-12). - itur/data/676/v13_h0_coefficients.txt: Part 1 oxygen equivalent-height coefficient file (700 frequencies, 1–350 GHz), downloaded from the ITU document server. - itur/models/itu676.py: new _ITU676_13_ class; default version bumped to 13. Validation (all against CG-3M3J-13-ValEx-Rev8.3.0.xlsx): - test/test_itu676_13.py: 21 dedicated unit tests. - test/ITU_validation_test.py: ITUR676_13TestCase added (16 assertions covering SpAtt, exact slant path Annex 1, and Annex 2 approx). - test/ITU_validation_report_test.py: ITUR676_13TestCase added with CSV- driven tests for gamma0, gammaw, gamma, and gaseous_attenuation_slant_path. - test/test_data/676/ITURP676-13_gamma.csv, test/test_data/676/ITURP676-13_A_gas.csv: new validation data files. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
inigodelportillo
force-pushed
the
claude/crazy-ramanujan
branch
from
3f5c19d to
b574803
Compare
Tests are covered by ITU_validation_test.py (ITUR676_13TestCase) and ITU_validation_report_test.py (ITUR676_13TestCase). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Generate HTML validation tables for ITU-R P.676-13 equivalent to the
existing P.676-12 tables, without modifying any pre-existing HTML files.
Changes:
- test/test_data/676/ITURP676-13_gamma.csv: expanded from 5 to 350 rows,
covering f = 1–350 GHz at standard conditions (P=1013.25 hPa,
T=288.15 K, rho=7.5 g/m³), values taken directly from the
'P.676-13 SpAtt' sheet of CG-3M3J-13-ValEx-Rev8.3.0.xlsx.
- test/ITU_validation_report_test.py: ITUR676_13TestCase now passes
prefixed test_name strings ('itur676_13_*') to __run__() so the
generated HTML files are uniquely named and do not overwrite the
P.676-12 tables.
- docs/validation/itur676_13.rst: regenerated to reference the new
prefixed HTML files.
- docs/validation/itur676_13_gamma0_table.html (new, 350 rows)
- docs/validation/itur676_13_gammaw_table.html (new, 350 rows)
- docs/validation/itur676_13_gamma_table.html (new, 350 rows)
- docs/validation/itur676_13_attenuation_gas_table.html (new, 10 rows)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Key changes from P.676-12
Annex 1 (exact line-by-line method):
Annex 2 (simplified method) — completely restructured:
h0is now computed from a Part 1 coefficient lookup table using Eq. 31:h0 = a0(f) + b0(f)·T + c0(f)·Ps + d0(f)·ρhwuses a new analytical formula (Eq. 37, Table 4 coefficients)γ0andγware computed via the exact (line-by-line) methodNew files
itur/data/676/v13_lines_oxygen.txt,v13_lines_water_vapour.txt— spectroscopic tables (identical to P.676-12)itur/data/676/v13_h0_coefficients.txt— Part 1 oxygen equivalent-height coefficients (700 frequencies, 1–350 GHz)test/test_itu676_13.py— 21 dedicated validation unit teststest/test_data/676/ITURP676-13_gamma.csv,ITURP676-13_A_gas.csv— validation data fromCG-3M3J-13-ValEx-Rev8.3.0.xlsxTest plan
All tests validated against
CG-3M3J-13-ValEx-Rev8.3.0.xlsx(ITU-R SG3 validation spreadsheet):test/test_itu676_13.py— 21 tests: specific attenuation (SpAtt sheet), exact slant path (A_Gas_A1 sheet), Annex 2 approx (A_Gas_A2_INST sheet)test/ITU_validation_test.py—ITUR676_13TestCase:gamma0_exact,gammaw_exact, slant path exact and approxtest/ITU_validation_report_test.py—ITUR676_13TestCase: CSV-driven tests forgamma0,gammaw,gamma,gaseous_attenuation_slant_path🤖 Generated with Claude Code