Sparse Sampling Reconstruction of Wind Fields for Space-Borne Doppler Radars

With its conically scanning W-band Doppler radar, the Wind Velocity Radar Nephoscope (WIVERN) ESA Earth Explorer 11 mission promises to provide, for the first time, global vertically resolved wind observations in cloudy and precipitating systems. Thanks to its observation geometry, WIVERN will measure line-of-sight (LoS) Doppler velocities of the same atmospheric volume from different viewing directions, allowing the complete reconstruction of the wind vector. To that end, a methodology to retrieve horizontal wind vectors for a conically scanning radar with a swath of 800 km and sparse sampling is developed in this work. The retrieval is applied to different meteorological systems, whose dynamics are simulated with a high-resolution cloud-resolving model. Results show that, in the presence of a healthy number of cloud targets in the scene, it is possible to reconstruct the zonal and meridional winds with uncertainty within 2-4 m/s. Accuracies deteriorate in the central part of the swath, close to the ground track, due to sparser sampling and interdependencies between different radar looks.