Measurements and results

As part of a research program, two methods were used to determine the brightness of the night sky:

• observational, astronomical (so called: cometary)
• instrumental (using the SQM)

The cometary method allow to determine the brightness of the night, cloudless sky since 1994, with any direct measurements of this value available in Poland. The intrumental method allowed for the direct measurement of the brightness of the night sky in any weather conditions.

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Databases of the sky brightness measurements done with the SQM-LE

• Measuring station No.1 (DOB) - water intake at the Dobczyce Reservoir
• Measuring station No.2 (SUH) - Mt Suhora Astronomical Observatory
• Measuring station No.3 (FSK) - Astronomical Observatory of the Jagiellonian University "Fort Skala"
• Measuring station No.4 (ZAB) - LP meteorological station in Zabierzów
• Measuring station No.5 (NIE) - Youth Astronomical Observatory in Niepołomice
• Measuring station No.6 (BOT) - Botanical garden in Kraków
• Measuring station No.7 (WIE) - Wieliczka
• Measuring station No.8 (KAS) - Kasinka Mała
• Measuring station No.9 (JER) - Jerzmanowice
• Measuring station No.10 (KLA) - Kraków-Łagiewniki

The owners of above databases, the Cracow University of Technology (PK - stations no. 1, 2, 4, 5, 6, 7, 8, 9, 10) and Astronomical Observatory of the Jagiellonian University (OA UJ - station no. 3) agree to use data from these databases by an authorized users, provided the source is acknowledged. Reproduction and publication of these data requires a consent of the owner.

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Comparison of the S_a values obtained by the cometary and instrumental methods

Measurement point	Coordinates	cometary method	SQM	difference	sample
Cracow	50°04' N 19°54' E	19,7	18,7	1,0	26 (comet.) 206 (SQM)
Lublin	51°14' N 22°33' E	19,4	18,6	0,8	28 (comet.) 4 (SQM)
Jerzmanowice near Cracow	50°12' N 19°45' E	21,4	20,6	0,8	17 (comet.) 120 (SQM)
Lubomir Range (Beskid Makowski)	49°45' N 20°02' E	21,5	20,9	0,6	24 (comet.) 5 (SQM)
Bieszczady Mountains	49°09' N 22°19' E	22,1	21,7	0,4	16 (comet.) 15 (SQM)