SWOT Level 2 Nadir Altimeter Operational Geophysical Data Record with Waveforms, GPS, NRT, Version D

The SWOT Level 2 Near Real Time GPS Nadir Altimeter Operational Geophysical Data Record (OGDR) Version D dataset produced by the Surface Water and Ocean Topography (SWOT) mission provides sea surface height, significant wave height and wind speed measurements from the Poseidon-3C nadir altimeter, a Jason-class dual frequency (Ku/C) altimeter. SWOT is a joint mission between NASA and CNES that launched on December 16, 2022.

It aims to measure ocean surface topography with unprecedented resolution and accuracy, as well as map inland water bodies globally. The NRT GPS OGDR dataset consists of discrete measurements along the nadir track with sampling resolutions of approximately 6-km and 300-m at 1Hz and 20Hz, respectively. The data were processed using a NRT GPS-based orbit ephemeris, with predicted values for certain auxiliary data and no GIM ionosphere model values.