Measurements of Sea Surface Currents in the Baltic Sea Region Using Spaceborne Along-Track InSAR
Artikel i vetenskaplig tidskrift, 2019

The main challenging problems in ocean current retrieval from along-track interferometric (ATI)-synthetic aperture radar (SAR) are phase calibration and wave bias removal. In this paper, a method based on differential InSAR (DInSAR) technique for correcting the phase offset and its variation is proposed. The wave bias removal is assessed using two different Doppler models and two different wind sources. In addition to the wind provided by an atmospheric model, the wind speed used for wave correction in this work is extracted from the calibrated SAR backscatter. This demonstrates that current retrieval from ATI-SAR can be completed independently of atmospheric models. The retrieved currents, from four TanDEM-X (TDX) acquisitions over the Öresund channel in the Baltic Sea, are compared to a regional ocean circulation model. It is shown that by applying the proposed phase correction and wave bias removal, a good agreement in spatial variation and current direction is achieved. The residual bias, between the ocean model and the current retrievals, varies between 0.013 and 0.3 m/s depending on the Doppler model and wind source used for wave correction. This paper shows that using SAR as a source of wind speed reduces the bias and root-mean-squared-error (RMSE) of the retrieved currents by 20% and 15%, respectively. Finally, the sensitivity of the sea current retrieval to Doppler model and wind errors are discussed.

Synthetic Aperture Radar (SAR)

Along-Track Interferometry (ATI)

sea surface currents

Doppler oceanography

Författare

Anis Elyouncha

Chalmers, Rymd-, geo- och miljövetenskap, Mikrovågs- och optisk fjärranalys

Leif Eriksson

Chalmers, Rymd-, geo- och miljövetenskap, Mikrovågs- och optisk fjärranalys

Roland Romeiser

Rosenstiel School of Marine and Atmospheric Science

Lars Ulander

Chalmers, Rymd-, geo- och miljövetenskap, Mikrovågs- och optisk fjärranalys

IEEE Transactions on Geoscience and Remote Sensing

0196-2892 (ISSN)

Vol. 57 11 8584-8599 8752096

Understanding ocean surface dynamics with satelite data

Rymdstyrelsen, 2015-01-01 -- 2019-03-31.

Ämneskategorier

Meteorologi och atmosfärforskning

Geofysik

Oceanografi, hydrologi, vattenresurser

DOI

10.1109/TGRS.2019.2921705

Mer information

Senast uppdaterat

2019-12-05