Added 38 per-date individual DSLR observations from Kassim Bahali et al. (2019)
JATMA 7(2):37-48 across 10 new sites:
- Sabang, Aceh, Indonesia (5.876°N, 95.340°E) — 11 nights Dec 2017
- Yaring, Pattani, Thailand (6.934°N, 101.319°E) — 2 nights Jan 2018
- Surabaya, East Java, Indonesia — 3 nights Feb 2018
- Sumenep, Madura, Indonesia — 3 nights Feb 2018
- Ternate, North Maluku, Indonesia — 3 nights Mar 2018
- South Sulawesi (Gowa area), Indonesia — 6 nights Mar 2018
- Mersing, Johor, Malaysia — 3 nights Jun 2018
- Kuala Rompin, Pahang, Malaysia — 2 nights Jul 2018
- Nenasi Pekan, Pahang, Malaysia — 2 nights Aug 2018
- Kota Tinggi, Johor, Malaysia — 3 nights Sep 2018
Depression angles computed via PyEphem from actual dawn times + coordinates.
Mean D0 range: 17.07° (Pattani) to 19.61° (Kota Tinggi dry season).
Includes first Thailand data point (Pattani) and expanded Indonesian coverage.
+10 new unique locations (88 → 98)
Added 32 new Fajr records from 8 new sites:
- 6 Indonesian cities from Saksono ISRN/UHAMKA 'Premature Dawn' series
(Padang, Batusangkar, Cirebon, Balikpapan, Bitung, Manokwari) — urban LP,
D0=-13.4°, 4 seasonal records each
- Tayu Beach, Pati, Central Java — Noor & Hamdani 2018 QIJIS, photoelectric+SQM,
D0=-17.0°, 4 individual nights Aug-Sep 2016
- Cimahi, West Java — Herdiwijaya 2020, SQM, D0=-18.5°, 4 seasonal records
+8 new unique locations (80 → 88)
New records from research expansion:
- Tanjung Aru, Sabah Malaysia (Niri & Zainuddin): 4 Isha Shafaq Abyad records
- Teluk Kemang, Malaysia (Abdel-Hadi & Hassan 2022): 4 Fajr + 4 Isha SQM records
- Bosscha Observatory, Java 1310m (Herdiwijaya 2020): 4 Fajr records
- Yogyakarta, Java (Herdiwijaya 2014-2016, 136 nights): 4 Fajr records
- Kupang, NTT 10°S (Herdiwijaya 2020): 4 Fajr + 4 Isha records
- Matrouh, Egypt (Hassan et al.): 4 Fajr + 3 Isha records (1 filtered)
- Kharga Oasis, Egypt (Hassan et al. 2020): 4 Fajr records
- Hurghada, Egypt (Hassan et al. 2020): 4 Fajr records
- Marsa-Alam, Egypt (Hassan et al. 2020): 4 Fajr records
- 15th of May City, Egypt (Taha et al. 2025): 4 Fajr records
- Riyadh, Saudi Arabia (Taha et al. 2025): 4 Fajr records
- Mauritania 18°N (Taha et al. 2025): 4 Fajr records — first West Africa data
New modules:
- src/geocode.py: Nominatim geocoding with disk cache
- src/ingest.py: CSV ingestion and data standardization pipeline
- src/pipeline.py: integrated raw CSV loading via ingest module
Replaces the original JS calibration library with a pure Python pipeline
for collecting and back-calculating solar depression angles from human-verified
Fajr and Isha prayer sightings.
What this does:
- src/pipeline.py: master pipeline; fetches iCal + manual records, back-calculates
angles via PyEphem, applies quality filters, exports two clean CSVs
- src/collect/openfajr.py: parses the OpenFajr Birmingham iCal feed (~4,018 records)
- src/collect/verified_sightings.py: manually compiled records from peer-reviewed
studies (Egypt, Saudi Arabia, Malaysia, Indonesia, UK, USA, Canada, and more)
- src/angle_calc.py: PyEphem back-calculation with atmospheric refraction
- src/elevation.py: Open-Elevation API batch lookup
Datasets generated:
- data/processed/fajr_angles.csv: 4,105 confirmed Fajr records, 35 locations,
latitude range -37.8 to 53.7 degrees, date range 1985-2026
- data/processed/isha_angles.csv: 43 confirmed Isha records, 20+ locations
Also includes:
- notebooks/01_exploratory_analysis.ipynb: latitude, TOY, elevation pattern analysis
- research/: academic paper summaries (not training data)
- data/raw/sources.md: full citation table for all data sources
Weighted least-squares calibration of Islamic prayer time depression
angles from observed mosque announcement data. Uses golden-section
search to minimize the sum of squared residuals independently for
Fajr and Isha. Internal Jean Meeus solar ephemeris — zero runtime
dependencies.
API: calibrateAngles, scoreAngles, predictFajr, predictIsha.
Full TypeScript, dual CJS/ESM via tsup.
32 ESM tests, 6 CJS tests, all passing on Node 20/22/24.
