The NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) mission

Abstract

The NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) is a spaceborne mission focused on tropical cyclone (TC) inner core process studies. CYGNSS attempts to resolve the principle deficiencies with current TC intensity forecasts, which lies in inadequate observations and modeling of the inner core. The inadequacy in observations results from two causes: 1) Much of the inner core ocean surface is obscured from conventional remote sensing instruments by intense precipitation in the eye wall and inner rain bands. 2) The rapidly evolving (genesis and intensification) stages of the TC life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers. CYGNSS is specifically designed to address these two limitations by combining the all-weather performance ofGNSS bistatic ocean surface scatterometry with the sampling properties of a constellation of satellites.

Recent progress on forward scattering modeling for GNSS reflectometry

“…To verify such an extended model available radiometric, scatterometric and GNSS-R data obtained in hurricanes can be used. The extended spectral model can be very useful for forward scattering modeling and evaluation of the performance and accuracy of the systems used in space-based missions such as CYGNSS [12].…”

Studying the Atmosphere Using Global Navigation Satellites

“…Two near-term planned missions, NASA's Cyclone Global Navigation Satellite System ( CYGNSS; 2016 launch) [Ruf et al, 2013] and the European Space Agency's GNSS Reflectometry, Radio Occultation and Scatterometry onboard the International Space Station mission ( GEROS-ISS; 2019 launch) [Wickert et al, 2013], will extend the use of GNSS signals further by using reflected signals from the ocean surface to measure surface wind speed and ocean topography.…”

Spaceborne GNSS-R Minimum Variance Wind Speed Estimator

“…This makes them particularly well suited for observing phenomena such as tropical cyclones [41], [42]. Scattering from the ocean at longer wavelengths is influenced by both the smaller capillary waves that are well coupled to local winds, and by longer (e.g., swell) waves which are less so.…”

“…The UK-DMC satellite was decommissioned in 2011, but a number of new spaceborne GNSS-R missions are expected to launch in the near future. The most important ones are: a) the UK TechDemoSat-1 (TDS-1) [44], [45], due to be launched in late 2013, which will provide a spaceborne platform for the demonstration of several new instrument concepts, and will host the next generation of SSTL's GPS-Reflectometry Receiver (called SGR-ReSI), and b) The NASA CYclone Global Navigation Satellite System (CYGNSS) Earth Venture mission, made up of a constellation of 8 microsatellites, which aims to measure sea surface winds in Tropical Cyclones (TC) and hurricanes, with a particular focus on their inner core [41], [42].…”