pray-calc-ml/.github/wiki/Data-Sources.md

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Data Sources

Complete citation table for all sighting records in the dataset.

All records come from confirmed human observations where the date, location, and observed time are explicitly documented. No aggregate statistics or angle guesses are used as ground truth. Each record is independently back-calculated using PyEphem.

Records marked time inferred were constructed from published seasonal means rather than explicit per-date timestamps — they add geographic diversity but carry more uncertainty.


Primary Source

OpenFajr Project — Birmingham, UK

Field Value
Records ~4,018 Fajr observations (after quality filter: ~4,087)
Location Birmingham, UK — 52.4862°N, 1.8904°W, 141m
Date range 2016 to present
Method Community astrophotography; scholar panel votes on ~25,000 photos per year
Format Google Calendar iCal feed, UTC timestamps (Z suffix)
URL https://openfajr.org
Collector src/collect/openfajr.py

This is the only known machine-readable dataset of per-date confirmed naked-eye Fajr observations anywhere in the world. It provides ~98% of the Fajr training data.


Manually Compiled Sources

United Kingdom

Location Lat Lng Elev Records Prayer Method Source
Blackburn, Lancashire 53.750°N 2.483°W 120m 29 Fajr + 32 Isha Fajr + Isha Naked eye, 6 Imams, 11 months Miftahi 2007 via Shaukat 2015 booklet, 1987-1988
Exmoor National Park 51.15°N 3.65°W 430m 8 Fajr + Isha Naked eye, multi-observer Asim Yusuf, Shedding Light on the Dawn, ISBN 978-0-9934979-1-9, 2017

Egypt

Location Lat Lng Elev Records Prayer Method Source
Kottamia Observatory 29.932°N 31.825°E 411m 3 Fajr Naked eye + Canon camera Marzouk et al. 2025, Springer AUASS, per-night D0 from Figs 1-5
Kharga Oasis 25.300°N 30.167°E 40m 2 Fajr Canon camera Marzouk et al. 2025, Springer AUASS, per-night D0 from Figs 7-8
Aswan 23.803°N 32.492°E 210m 4 Fajr Nikon + Canon camera Marzouk et al. 2025, Springer AUASS, per-night D0 from Figs 10-21
Fayum 29.283°N 30.050°E 50m 2 Fajr CCD + Canon camera Marzouk et al. 2025, Springer AUASS, per-night D0 from Figs 25-27
Kottamia Observatory 29.929°N 31.825°E 477m 6 Fajr + Isha Photoelectric + naked eye Hassan et al., NRIAG J. 3:23-26, 2014
Wadi Al Natron 30.5°N 30.15°E 23m 7 Fajr + Isha Naked eye Semeida & Hassan, BJBAS 7:286-290, 2018

Saudi Arabia and Arabian Peninsula

Location Lat Lng Elev Records Prayer Method Source
Riyadh 25.767°N 47.200°E 540m 13 Fajr Naked eye + Nikon D70 Taha et al. 2025, EJSAS 3(1):4-17, per-night D0 from Table 7
Hail 27.52°N 41.70°E 1020m 8 Fajr + Isha Naked eye, 32 selected nights Khalifa, NRIAG J. 7:22-28, 2018

Mauritania

Location Lat Lng Elev Records Prayer Method Source
Jeneifisa (Mur.1) 20.850°N 14.383°W 170m 5 Fajr Naked eye, deep Saharan desert Taha et al. 2025, EJSAS 3(1):4-17, per-night D0 from Table 9
Jorf (Mur.2) 20.250°N 15.283°W 91m 5 Fajr Naked eye, deep Saharan desert Taha et al. 2025, EJSAS 3(1):4-17, per-night D0 from Table 9

Malaysia

Location Lat Lng Elev Records Prayer Method Source
Pekan, Pahang 3.408°N 103.356°E 5m 1 Fajr DSLR + SQM Kassim Bahali et al. 2019, IJMET 10(2):1136-1150, Table 6
Dungun, Terengganu 4.795°N 103.426°E 5m 3 Fajr DSLR + SQM Kassim Bahali et al. 2019, IJMET 10(2):1136-1150, Table 6
Sabang, Aceh 5.876°N 95.339°E 5m 5 Fajr DSLR + SQM Kassim Bahali et al. 2019, IJMET 10(2):1136-1150, Table 6
Kuala Lumpur 3.14°N 101.69°E 40m 4 Fajr DSLR + SQM Kassim Bahali et al., Sains Malaysia 47(11):2797-2805, 2018
Kuala Terengganu 5.283°N 103.099°E 5m 1 Fajr DSLR Kassim Bahali 2018, Sains Malaysiana Fig 4

Indonesia (Basthoni 2022 SQM Network)

1,621 per-night SQM records across 46 Indonesian sites, extracted from all four appendices of Basthoni's 2022 PhD dissertation at UIN Walisongo. Each record is a direct instrument measurement where the Fajr depression angle was determined by linear fitting of SQM time-series data.

Lampiran 2 (Dark, >= 21.3 mpsas): 637 records, 10 sites

Location Lat Lng Elev Records Method Source
Karimunjawa 5.823°S 110.491°E 1m 252 SQM time-series, linear fitting Basthoni 2022, Lampiran 2
Agam, W. Sumatra 0.204°S 100.320°E 855m 151 SQM time-series Basthoni 2022, Lampiran 2
Garut, W. Java 7.650°S 107.692°E 10m 101 SQM time-series Basthoni 2022, Lampiran 2
Banyuwangi, E. Java 8.028°S 114.425°E 1m 60 SQM time-series Basthoni 2022, Lampiran 2
Biak, Papua 1.174°S 136.101°E 47m 39 SQM time-series Basthoni 2022, Lampiran 2
Masalembu 5.586°S 114.436°E 1m 10 SQM time-series Basthoni 2022, Lampiran 2
4 more sites various various 1-1282m 24 SQM time-series Basthoni 2022, Lampiran 2

Lampiran 3 (Somewhat Dark, 20.2-21.2 mpsas): 337 records, 9 sites

Location Lat Lng Elev Records Method Source
Bosscha, W. Java 6.817°S 107.617°E 1300m 189 SQM time-series Basthoni 2022, Lampiran 3
Biak, Papua 1.174°S 136.101°E 47m 109 SQM time-series Basthoni 2022, Lampiran 3
Pontianak, W. Kalimantan 0.050°S 109.334°E 10m 17 SQM time-series Basthoni 2022, Lampiran 3
6 more sites various various 1-855m 22 SQM time-series Basthoni 2022, Lampiran 3

Lampiran 4 (Somewhat Bright, 19.1-20.1 mpsas): 418 records, 9 sites

Location Lat Lng Elev Records Method Source
Mangkangkulon, Semarang 6.967°S 110.291°E 5m 154 SQM time-series Basthoni 2022, Lampiran 4
Pasuruan, E. Java 7.617°S 112.908°E 6m 87 SQM time-series Basthoni 2022, Lampiran 4
Pontianak, W. Kalimantan 0.050°S 109.334°E 10m 59 SQM time-series Basthoni 2022, Lampiran 4
Subang, W. Java 6.567°S 107.750°E 110m 59 SQM time-series Basthoni 2022, Lampiran 4
5 more sites various various 1-855m 59 SQM time-series Basthoni 2022, Lampiran 4

Lampiran 5 (Bright/Urban, < 19.1 mpsas): 229 records, 18 sites

Location Lat Lng Elev Records Method Source
Medan, N. Sumatra 3.595°N 98.672°E 22m 28 SQM time-series Basthoni 2022, Lampiran 5
Depok, W. Java 6.383°S 106.830°E 150m 15 SQM time-series Basthoni 2022, Lampiran 5
Paopao, Central Sulawesi 0.917°S 119.850°E 50m 13 SQM time-series Basthoni 2022, Lampiran 5
15 more sites various various 1-1300m 173 SQM time-series Basthoni 2022, Lampiran 5

Indonesia (Other Sources)

Location Lat Lng Elev Records Prayer Method Source
BRIN Mt. Timau, NTT 9.6°S 123.8°E 1282m 59 Fajr Fajr SQM-LE continuous BRIN multistation network, data/raw/raw_sightings/
7 BRIN stations various various 2-1282m 577 Isha Isha SQM-LE continuous BRIN multistation network

North America

Location Lat Lng Elev Records Prayer Method Source
Ithaca, NY, USA 42.44°N 76.50°W 270m 2 Fajr Naked eye, 3 observers Omar Afzal via Shaukat 2015 booklet, Sep 1991
Tando Adam, Pakistan 25.76°N 68.66°E 25m 2 Fajr Naked eye Ludhianvi 1975 via Shaukat 2015 booklet, Jun 1970

Europe

Location Lat Lng Elev Records Prayer Method Source
Pampigny, Switzerland 46.57°N 6.39°E 570m 1 Fajr Camera observation Ouared via Shaukat 2015 booklet, Jun 2016

Source Quality Summary

Dataset counts as of pipeline run 2026-05-30: 48,668 Fajr + 34,529 Isha

Tier Description Sources Approx count
1 — Voted astrophotography OpenFajr Birmingham iCal OpenFajr ~4,018 Fajr
2 — Instrumental (SQM), per-night Basthoni 2022 PhD, 46 Indonesian sites (Lampiran 2-5) 1 source, 46 sites ~1,621 Fajr
3 — Instrumental (DSLR/SQM), per-night Kassim Bahali 2018+2019, BRIN multistation 3 sources ~70 Fajr+Isha
4 — Multi-observer naked eye, per-date Blackburn UK (29+32), Asim Yusuf UK, Taha Riyadh+Mauritania 4 sources ~95 Fajr+Isha
5 — Camera/instrument per-night (D0 from paper) Marzouk 2025 Egypt, Khalifa 2018 Hail 2 sources ~19 Fajr+Isha
6 — Single observer, explicit timestamps Shaukat booklet sites, moonsighting.com 5+ sources ~12 Fajr+Isha

Data Availability Assessment

After an extensive search (February 2026) covering >80 academic sources and community programs:

What exists at scale: Only one known machine-readable per-date observation feed exists: OpenFajr Birmingham (~4,018 records). The second-largest source is Basthoni's 2022 PhD dissertation from UIN Walisongo, with 1,621 per-night SQM records across 46 Indonesian sites (now fully extracted from all four appendices). All other sources publish per-date tables in academic papers (a few dozen records each) or aggregate D0 statistics only.

What the global research corpus contains: ~8-15k verified per-date records in total across all known published sources. Most Egyptian, Indonesian, Malaysian, Pakistani, and Middle Eastern research papers report seasonal mean D0 values, not per-date tables.

Confirmed negative search results (Feb 2026): Pakistan (moonsighting.com, Ruet-e-Hilal), Sudan, East Africa, Central Asia, Faid et al. 2024 per-night data (84 observations unpublished), Herdiwijaya per-night tables (83 data points visible in scatter plots only). Globe at Night SQM archives are night-sky brightness only, not prayer time observations.

Priority Gaps

The most critical data gaps by region and prayer:

Region Prayer Gap Potential source
All regions Isha Only 46 records total Shafaq al-Abyad observation logs; contact NRIAG researchers
South America Fajr + Isha Zero records Muslim community programs in Brazil, Argentina, Colombia
High latitudes 55°N+ Fajr Zero records Scandinavian Muslim communities, northern Canada
Sub-Saharan Africa Fajr Very few records West African observation networks
Central Asia Fajr + Isha Zero records Uzbekistan, Kazakhstan, Afghanistan
Long-running SQM archives Fajr + Isha Per-date data held by researchers, not published Direct contact with NRIAG Egypt, OIF UMSU, Faid et al. 2024

How to Contribute

If you have access to per-date sighting records with explicit times, dates, and locations, open src/collect/verified_sightings.py and add entries following the format on the Data Collection page.

To propose a citation for review, open an issue on the GitHub repository with:

  • Full bibliographic citation
  • Location coordinates and elevation
  • Date range of the observation program
  • How many individual per-date records are published

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