5‐cm‐Precision aircraft ocean altimetry using GPS reflections

We present the first two aircraft Global Positioning System (GPS)‐reflection altimetry measurements, the most precise GPS ocean‐altimetry measurement, and demonstrate the altimetric precision and spatial resolution necessary to map mesoscale eddies. Our first experiment demonstrated a 14‐cm precision single‐satellite ocean altimetry measurement while our more recent experiment demonstrates 5 cm altimetric precision with 5‐km spatial resolution. The new results show significant improvement over our previous effort, due to improved modeling, greater aircraft altitudes and velocities, improved receiver positioning, and better experimental control. Plans to further reduce speckle and refine models to obtain 5‐cm altimetric accuracy are presented.