The GANDER Microsatellite Radar Altimeter Constellation for Global Sea State Monitoring

In the last two decades satellite borne radar altimetry has been demonstrated as a very effective and accurate remote sensing method in sea state monitoring by over ten missions. Although all the previous missions have focused on oceanography, glaciology and land topography study, radar altimeter\u27s unique advantage in providing fast access altimetry measurement of significant wave height (SWH) and sea swface wind speed sensing has also generated great interests in several commercial applications such as a constellation for global real time sea safety monitoring and the shipping route management. In this paper, a low cost 12 microsatellite network called GANDER constellation (Global Altimeter Network Designed to Evaluate Risk), jointly proposed by Surrey Space Centre (SSC) and Satellite Observations System (SOS), is presented. The paper first gives an outline of the radar altimeter\u27s operational principle and main applications, then it focuses on a thorough feasibility analysis to demonstrate the microsatellite capability in this project, payload requirements as well as several most critical platform subsystems will be studied in detail. In the end, the 12 microsatellite constellations arrangement, which aims to provide world wide users of near real time access will be defined. This 12 small satellite system, as a much cheaper and more effective alternative for the conventional\u27 big\u27 multisensors spacecraft, will allow a much faster and more frequent update for the global sea state change monitoring. Its appearance well presents the small satellite research and application trend - cheaper by the dozens, andfaster by smaller