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
2.6 KiB
Naked Eye Determination of the Dawn at Tubruq of Libya Through Four Years Observations
Authors: A.H. Hassan and Yasser A. Abdel-Hadi Year: 2015 Journal: Middle-East Journal of Scientific Research, 23(11): 2627-2632 DOI: 10.5829/idosi.mejsr.2015.23.11.22607 URL: https://www.idosi.org/mejsr/mejsr23(11)15/3.pdf Sites studied: Tubruq, Libya (S2 site: desert background, 7km inland from coast) Observation method: Naked eye Date range: January 2010 to July 2013 (S2); December 2007 to December 2009 (S1) Records: 623 twilight observations (S2), 429 (S1), total 1052 Mean angle (Fajr): S2: 13.144 +/- 0.757 (high confidence D0 = 14.7 using mean+2sigma)
Location Details
- S1: 32 05'N, 23 59'E, 10m elevation, Mediterranean coast, water vapor background
- S2: 32 05'N, 23 59'E, 40m elevation, desert background, 7km south of S1
Summary
The largest single-site naked-eye Fajr observation campaign in the published literature. 623 observations at site S2 (desert background, 40m elevation) from 2010-2013 produced a mean depression angle of 13.144 degrees with standard deviation 0.757 degrees. The distribution ranges from 11.13 to 14.7 degrees.
The paper uses the "high confidence" convention of D0 = mean + 2 sigma = 14.7 degrees, which represents the 99.77th percentile. The mode is 13.372 degrees (in the 13.14-13.39 range, 14.6% of observations).
S1 (coastal, water vapor background) gave a lower mean of 12.351 degrees with high confidence of 13.43 degrees, attributed to reduced visibility from water vapor.
Key Table 4 gives frequency distribution across 14 bins of width 0.255 degrees. Table 5 gives finer 0.1 degree bins in the 14.0-14.7 range (91 observations total, 14.4% of S2 data).
The paper compares the 14.7 result with the official Libyan value of 18.25, finding a difference of 3.55 degrees (18-23 minutes).
Data Availability
AGGREGATE ONLY. The paper reports statistical distributions (Tables 1-5) and histograms, but does NOT publish per-night dates, times, or individual D0 values. Only bin counts are available.
The 14-bin frequency distribution (Table 4) and 7-bin fine distribution (Table 5) provide histogram data that could be used for distribution modeling, but not per-night angle extraction.
For ML Training
This paper cannot provide per-night training rows. However, the aggregate statistics are valuable:
- n=623, mean=13.144, sigma=0.757, min=11.13, max=14.7 at lat 32.08, lng 23.98, elev 40m
- Can generate representative seasonal samples using the distribution parameters
- Already referenced in research/aggregate_d0_database.csv