Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Selected technical parameters of the measuring device_
| Parameter | Characteristic |
|---|---|
| weight | 380 g |
| dimension | 5,5 × 8,2 × 15,8 cm |
| standard of data transmission | LoRaWAN |
| frequency bands | 868 MHz |
| operating time [3 000 mAh] | ∼ 12 month |
| range in built-up areas | 3–4 km |
| number of measurements during the day | 36 |
| frequency of measurements | 15 min |
| operational time | 21:00–06:00 CEST |
| measuring sensors | surface brightness of the sky, temperature, humidity |
| the angle of data collection | 20° |
| tightness class | IP65 |