1. A computer-implemented method for analyzing a Global Navigation Satellite System (GNSS) receiver comprising: receiving, by the computer, electronic diagnostic information from the GNSS receiver, said diagnostic information comprising a plurality of observations at different times of signal strength of one or more satellites at each point in a visible sky; building, by the computer, a flat map of the visible sky using the received diagnostic information, wherein the flat map includes a track of the one or more satellites; calculating, by the computer, for each point in the visible sky of the flat map, an aggregated signal strength of the one or more satellites over a predetermined interval using the received diagnostic information; generating, by the computer, a heat map over the flat map of the visible sky and the calculated aggregated signal strengths; displaying, by the computer, a visualization of a flat heat map on a graphical user interface of a display device, the flat heat map comprising the generated heat map over the flat map of the visible sky; and, storing, by the computer, the diagnostic information and the flat heat map in an observation database.