Christine Gommenginger (National Oceanography Centre, United Kingdom); Meric Srokosz (National Oceanography Centre, United Kingdom)

Sea state bias is the largest unknown remaining in SAR altimetry measurements today as there is currently no solution available. Due to the asymmetric shape of the SAR altimeter footprint, SAR observations have the potential for sea state bias errors to be greater depending on the relative directions of the ground track and swell propagation. Our investigation has addressed this problem using observations from Envisat ASAR measurements of swell length, height and direction, through Globwave data, which we have collocated with Cryosat2 L1B data. The study area focused on SAR boxes in the North and West Atlantic, the Equatorial Atlantic and the Agulhas region. Averaged waveforms are ordered by swell direction, swell wavelength and wave height to form a matrix of results within similar conditions. We also show comparative results of the effects of the L1B processing to the collocated waveforms in this study.