ada08e7ec4
Add 6 new data collection pipelines and their processed outputs: Sources added: - TESS/Stars4All photometer network: 37 months (Jun 2017-Aug 2020), ~40k raw events from 100+ European stations via Zenodo archives - Globe at Night citizen science: 26k twilight observations (2006-2024), filtered from 308k total observations for solar depression 6-22 deg - GaN-MN continuous monitoring: 45 months (Jan 2022-Sep 2025), ~12.5k twilight events from 88 stations across 20+ countries - Galicia SQM network: 14 stations, 1-min resolution, 7.5k events - Madrid/Majadahonda SQM: multi-year continuous monitoring, 3.1k events - washetdonker.nl Netherlands: 7 stations, 3.3k morning events - Academic papers: Jordan (Abed 2015), Fayum Egypt, India photometer Pipeline changes: - ingest.py: add all new files to APPROVED_RAW_CSVS allowlist, fix filter to use allowlist instead of hardcoded exclusions - .gitignore: exclude bulk raw data directories (BSRN, TESS, GaN-MN, washetdonker, Globe at Night downloads) Final dataset: 56,668 Fajr + 34,763 Isha = 91,431 total records Previous: 5,871 Fajr + 46 Isha = 5,917 total records |
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| .. | ||
| outreach | ||
| abed-2015-jordan.md | ||
| aggregate_comparison.md | ||
| aggregate_d0_values.csv | ||
| baghdad-sky-brightness-2021.md | ||
| birmingham-openfajr.md | ||
| fayum-egypt-2022.md | ||
| hail-saudi-2018.md | ||
| malaysia-indonesia-2018.md | ||
| malaysia-light-pollution-2024.md | ||
| nriag-egypt-4sites-2014.md | ||
| nriag-egypt-1984-2014.md | ||
| README.md | ||
| tubruq-libya-2015.md | ||
| uk-observations.md | ||
Research Archive
This folder contains summaries of academic and institutional research on Islamic twilight
angles. These papers describe other researchers' conclusions about the solar depression angle
at Fajr and Isha. They are useful for understanding the scientific landscape but are not
used as ML training data — only raw per-date observations with explicit timestamps feed
the data/processed/ datasets.
Summary: What the research says
Most peer-reviewed naked-eye studies find Fajr (true dawn / Subh Sadiq) corresponds to a solar depression of roughly 13°–16° depending on site, season, and atmospheric conditions. Isha (Shafaq al-Abyad, white dusk twilight) corresponds to roughly 14°–18°.
The classic convention of 18° Fajr (used by ISNA, MWL, and others) is based on astronomical twilight (the sky becoming fully dark), not the first appearance of dawn light. Observations consistently show true dawn appears while the sun is 12°–15° below the horizon, not 18°.
Papers Summarized
| File | Authors | Year | Site | Finding |
|---|---|---|---|---|
nriag-egypt-1984-2014.md |
Hassan et al. | 1984-2014 | Egypt (6 sites) | 13°-15° Fajr |
nriag-egypt-2022-2025.md |
Rashed et al. | 2018-2025 | Egypt (Fayum, Alex) | 13°-14° Fajr |
hail-saudi-2018.md |
Khalifa | 2014-2015 | Hail, Saudi Arabia | 14° mean Fajr |
malaysia-indonesia-2018.md |
Kassim Bahali | 2017 | KL + Indonesia | 16.67° Fajr |
depok-indonesia-2020.md |
Saksono | 2015 | Depok, Java | ~16° Fajr |
uk-observations.md |
Yusuf, Hizbul Ulama | 1987-2017 | UK (3 sites) | 12°-14° Fajr |
birmingham-openfajr.md |
OpenFajr project | 2016-2026 | Birmingham | 12.5°-14° Fajr |
moonsighting-global.md |
Khalid Shaukat | 2000s | Multiple global | 15°-18° Fajr |