A CYGNSSâ Based Algorithm for the Detection of Inland Waterbodies

The Cyclone Global Navigation Satellite System (CYGNSS) is a new constellation of eight low Earth orbiting spacecrafts that receive both direct and reflected signals from GPS satellites. Coherent reflection of the GPS signal from standing water over land results in a high surface reflectivity signal in the CYGNSS data. An image processing algorithm is presented, which leverages the surface reflectivity signal to produce a watermask of inland waterbodies at 0.01° à 0.01° spatial resolution. The watermask is compared to handâ drawn maps of inland waterbodies, as well as to the MODIS watermask product. We find that the CYGNSS watermask provides accurate, timeâ varying maps that are able to resolve changes in lake and river position and extent. With CYGNSS’ short return time, watermasks can be generated using as little as half a month of data to produce nearâ realâ time maps of flooding events.Key PointsThe Cyclone Global Navigation Satellite System satellite constellation data are used to map inland water bodiesWe propose an algorithm to process this new data and create watermasks of rivers and lakesThe data combined with this method can be applied to monitor shortâ term events such as seasonal floodingPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153138/1/grl59790.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153138/2/grl59790_am.pd