Light Pollution Map vs MagVar

The map displays VIIRS/World Atlas/Clouds/Aurora/IAU observatories and the user SQM measurements. 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, aurora and IAU observatories. If you have a permanent SQM reader installed you can add it to the map by sending me an e-mail. Please send comments and requests for new features via email (look under help) Functionalities: - VIIRS, Sky Brightness, World Atlas 2015, Cloud coverage and Aurora forecast layers - VIIRS and Sky Brightness layers can be displayed in color blind friendly colors - Road & Satellite base maps - Cloud animation for the last 12 hours - Get detail radiance and SQM values from layers at a click. For Sky brightness/World Atlas 2015, you also get Bortle class estimation. - SQM, SQM-L, SQC, SQM-LE, SQM readings submitted by users - International dark sky parks overlay - Submit your own SQM (L) readings - Observatories layer - Save your favorite locations - Distance measurement tool with azimuth angle report - All-sky view of light pollution with real horizon - Offline mode (Sky brightness map and a base map are saved to your device, so it will be displayed when you are offline)

MagVar is targeted towards anyone interested in navigation. This includes, pilots of aircraft, captains of sea going vessels, cartographers, engineers and surveyors. Anyone who uses maps and a compass will find the declination calculation (also referred to magnetic variation) very useful. (Declination is the difference between true and magnetic north and used when plotting a course on a map.) MagVar calculates the magnetic flux density for any location on the Earth and then uses this data to calculate magnetic variation. The model is accurate for dates ranging from January 1, 2025 up through December 31, 2029. Using the model, the app calculates declination and inclination. As the user pans the map, the magnetic variation is calculated and graphically shown as a map overlay.