Next Article in Journal
A Review of Deep Learning-Based Methods for Pedestrian Trajectory Prediction
Next Article in Special Issue
Investigation of the Possibility of Using Microspectrometers Based on CMOS Photodiode Arrays in Small-Sized Devices for Optical Diagnostics
Previous Article in Journal
An Extended Methodology for Sizing Solar Unmanned Aerial Vehicles: Theory and Development of a Python Framework for Design Assist
Previous Article in Special Issue
Inquiry into the Temperature Changes of Rock Massif Used in Energy Production in Relation to Season

Verification of Angular Response of Sky Quality Meter with Quasi-Punctual Light Sources

CISAS—Center for Studies and Activities for Space “Giuseppe Colombo”, University of Padova, Via Venezia 15, 35131 Padova, Italy
Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padova, Italy
Department of Physics and Astronomy, University of Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
Author to whom correspondence should be addressed.
Academic Editor: Francesco De Leonardis
Sensors 2021, 21(22), 7544;
Received: 12 October 2021 / Revised: 3 November 2021 / Accepted: 9 November 2021 / Published: 13 November 2021
(This article belongs to the Special Issue Sensors Based on Optical and Photonic Devices)
Sky Quality Meter (SQM) is a commercial instrument based on photometers widely used by amateur astronomers for skyglow measurement from the ground. In the framework of the MINLU project, two SQM-LE units were integrated in an autonomous sensor suite realized and tested at University of Padova for monitoring light pollution from drones or sounding balloons. During the ground tests campaign before airborne measurement, the performance of both SQM units was verified in laboratory using controlled light sources as a reference input; the results showed that both units presented an angular response deviating consistently from the expected performance and that the sensors’ field of view was larger than the one declared in the manufacturer’s datasheet. This aspect in particular would affect direct skyglow measurements during flight as light sources close to the boundaries of the field of view would not be attenuated but instead detected by the sensors. As a direct consequence, the measurement of low-intensity skyglows at stratospheric altitudes could be affected by high-intensity punctual sources acting as lateral disturbances. A dedicated test campaign was therefore conceived and realized to investigate SQM unit response to light sources in the field of view and identify the true angular response curve; the setup consisted in a controlled rotatory stage moving the unit in front of a fixed diffusive light source. Different test conditions were used to validate the experimental procedure, demonstrating the repeatability of the measurements. This paper presents the experimental campaign and the resulting SQM angular response curve; results indicate for both SQMs a larger than expected field of view and the presence of a double peak in the angular response, which is likely related to a non-perfect alignment of SQMs collimation optics. Furthermore, the wider resulting curves suggest that the contribution of lateral sources is more prominent with respect to the response predicted by the manufacturer. For this reason, the utilization of baffles to restrict SQMs field of view is analyzed to minimize the disturbance of lateral light sources and two different geometries are presented. View Full-Text
Keywords: sky quality meter; light pollution; sky brightness sky quality meter; light pollution; sky brightness
Show Figures

Figure 1

MDPI and ACS Style

Bartolomei, M.; Olivieri, L.; Bettanini, C.; Cavazzani, S.; Fiorentin, P. Verification of Angular Response of Sky Quality Meter with Quasi-Punctual Light Sources. Sensors 2021, 21, 7544.

AMA Style

Bartolomei M, Olivieri L, Bettanini C, Cavazzani S, Fiorentin P. Verification of Angular Response of Sky Quality Meter with Quasi-Punctual Light Sources. Sensors. 2021; 21(22):7544.

Chicago/Turabian Style

Bartolomei, Mirco, Lorenzo Olivieri, Carlo Bettanini, Stefano Cavazzani, and Pietro Fiorentin. 2021. "Verification of Angular Response of Sky Quality Meter with Quasi-Punctual Light Sources" Sensors 21, no. 22: 7544.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop