Atmospheric Grid Analysis & Profile Extraction (AGAPE)

When low earth orbit (LEO) satellites receive GPS signals that have first traveled though the atmosphere we refer to this as an atmospheric radio occultation. They occur in that brief window when a LEO satellite sets or rises behind the earth relative to the GPS satellite line of site.

When you send multiple frequencies through a medium you can look at the difference in how those frequencies refract through that medium to infer qualities of the medium. In this sense, each of these occultations is a measurement of the atmosphere. I built this data browser (AGAPE) for the GENESIS project at JPL to facilitate downloads of nearly 10 million occultation measurements over the last several decades.