*2.4. Geographic Information System*

The geographic information system used in our research was QGIS [27], a free and open source software. We used QGIS to show different layers with several georeferenced attributes related to the public lighting installation. For each street or road, each layer showed the average luminance or illuminance value, uniformity (ratio of the minimum and average magnitude), position of luminaries, electrical energy consumed by luminaries and along the street, energy efficiency for each street or road, and the corresponding energy class (A, B, C, etc.). Figure 6 shows an example of one of the aerial images georeferenced with the QGIS software.

**Figure 6.** Aerial image taken with an airborne camera. The image was georeferenced with QGIS.
