What satellites are above you right now? Patricio Gonzales Vivo wanted to find out, so he built Line of Sight using Tangram, a few Mapzen services, open orbital data and open source software libraries.
Patricio was looking into how use ham radio to communicate with satellites. The antennas have to be aimed, so he combined data from SatNOGS (an open database of satellite transmitters) and CelesTrak (a list of satellite codes), into GeoJSON using Python. He then used the satellite.js library to pass satellite orbital data into Tangram.
Line of Sight uses Mapzen Search and Elevation to calculate the azimuth (direction) and elevation (angle) for a satellite over the next hour. Patricio decided to dynamically encode the locations of those satellites into image that can be quickly processed by Tangram. The longitude of 500 interesting, visible (and soon-to-be visible) satellites is encoded on the left side of the image, and their latitude is on the right.
Have a look at the code on Github.