The map displays VIIRS/DMSP/World Atlas/Clouds/IAU observatories and the user SQM measurements overlay over Microsoft Bing base layers (road and hybrid Bing maps).

The primary use is to show VIIRS/DMSP data in a friendly manner, but over time it also included some other interesting overlays that concern light pollution like SQM/SQC, World Atlas 2015 zenith brightness, clouds and IAU observatories. If you have a permanent SQM reader installed you can add it to the map by sending me an e-mail.

Annual VIIRS comparisons are to be avoided as there are too many factors involved by just doing a direct comparison. If you want an analysis of radiance (VIIRS/DMSP) changes over a period of time, then please use the Lighttrends application (look under Help).

Functionalities:
- VIIRS, Sky Brightness and Cloud layers
- Road & Terrain base maps
- Cloud animation for the last 12 hours
- Get detail radiance and SQM values from layers at a click. For World Atlas 2015, you also get Bortle class estimation.
- SQM, SQM-L, SQC, SQM-LE, SQM readings submitted by users
- Submit your own SQM (L) reading
- Observatories layer
- Save your favorite locations
- Distance measurement tool with azimuth angle report
- Offline mode (Sky brightness map and a base map are saved to your device, so it will be displayed enem od you are offline)