Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR)
The synthetic aperture radar (SAR) Doppler centroid shift has been demonstrated to contain geophysical information about sea surface wind, waves and current at an accuracy of 5 Hz and pixel spacing of 3.5 − 9 × 8 km2. This corresponds to a horizontal surface velocity of about 20 cm/s at 35◦ incidenc...
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ftzenodo:oai:zenodo.org:7414314 2024-09-15T18:20:29+00:00 Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) Hansen, Morten W. Johnsen, Harald Engen, Geir Park, Jeong-Won Moiseev, Artem 2018-11-01 https://doi.org/10.5281/zenodo.7414314 eng eng Zenodo https://zenodo.org/communities/nersc-research https://doi.org/10.5281/zenodo.7414313 https://doi.org/10.5281/zenodo.7414314 oai:zenodo.org:7414314 info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode Synthetic aperture radar Ocean circulation Nordic Seas Geophysical Doppler shift Wind info:eu-repo/semantics/report 2018 ftzenodo https://doi.org/10.5281/zenodo.741431410.5281/zenodo.7414313 2024-07-25T19:58:29Z The synthetic aperture radar (SAR) Doppler centroid shift has been demonstrated to contain geophysical information about sea surface wind, waves and current at an accuracy of 5 Hz and pixel spacing of 3.5 − 9 × 8 km2. This corresponds to a horizontal surface velocity of about 20 cm/s at 35◦ incidence angle. The ESA Prodex ISAR project aims to implement new and improved SAR Doppler shift processing routines to enable reprocessing of the wide swath acquisitions available from the Envisat ASAR archive (2002-2012) at higher resolution and better accuracy than previously obtained, allowing combined use with Sentinel-1 and Radarsat-2 retrievals to build timeseries of the sea surface velocity in the Nordic Seas. This project has addressed the calibration and validation of geophysical Doppler shifts from Envisat ASAR Doppler centroid shift retrievals. The main focus has been the challenges related to estimation of geometric (satellite orbit and attitude) and electronic (antenna mis-pointing) contributions and corrections. Geophysical Doppler shifts from approximately three months of data in January, February and March 2010 have been analyzed with the goal of establishing a global calibration algorithm. At 8 km pixel spacing, the uncertainty of the retrieved geophysical Doppler shift is then about 2.5 Hz in subswaths 2-5, and 3.5 Hz in subswath 1. This is half the uncertainty of previous results. Following this, new and improved routines for near-surface wind and current retrieval in the Nordic Seas have been developed, and a validation framework has been established. The preliminary results are then presented NERSC Technical Report no. 397 Report Nordic Seas Zenodo |
institution |
Open Polar |
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Zenodo |
op_collection_id |
ftzenodo |
language |
English |
topic |
Synthetic aperture radar Ocean circulation Nordic Seas Geophysical Doppler shift Wind |
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Synthetic aperture radar Ocean circulation Nordic Seas Geophysical Doppler shift Wind Hansen, Morten W. Johnsen, Harald Engen, Geir Park, Jeong-Won Moiseev, Artem Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) |
topic_facet |
Synthetic aperture radar Ocean circulation Nordic Seas Geophysical Doppler shift Wind |
description |
The synthetic aperture radar (SAR) Doppler centroid shift has been demonstrated to contain geophysical information about sea surface wind, waves and current at an accuracy of 5 Hz and pixel spacing of 3.5 − 9 × 8 km2. This corresponds to a horizontal surface velocity of about 20 cm/s at 35◦ incidence angle. The ESA Prodex ISAR project aims to implement new and improved SAR Doppler shift processing routines to enable reprocessing of the wide swath acquisitions available from the Envisat ASAR archive (2002-2012) at higher resolution and better accuracy than previously obtained, allowing combined use with Sentinel-1 and Radarsat-2 retrievals to build timeseries of the sea surface velocity in the Nordic Seas. This project has addressed the calibration and validation of geophysical Doppler shifts from Envisat ASAR Doppler centroid shift retrievals. The main focus has been the challenges related to estimation of geometric (satellite orbit and attitude) and electronic (antenna mis-pointing) contributions and corrections. Geophysical Doppler shifts from approximately three months of data in January, February and March 2010 have been analyzed with the goal of establishing a global calibration algorithm. At 8 km pixel spacing, the uncertainty of the retrieved geophysical Doppler shift is then about 2.5 Hz in subswaths 2-5, and 3.5 Hz in subswath 1. This is half the uncertainty of previous results. Following this, new and improved routines for near-surface wind and current retrieval in the Nordic Seas have been developed, and a validation framework has been established. The preliminary results are then presented NERSC Technical Report no. 397 |
format |
Report |
author |
Hansen, Morten W. Johnsen, Harald Engen, Geir Park, Jeong-Won Moiseev, Artem |
author_facet |
Hansen, Morten W. Johnsen, Harald Engen, Geir Park, Jeong-Won Moiseev, Artem |
author_sort |
Hansen, Morten W. |
title |
Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) |
title_short |
Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) |
title_full |
Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) |
title_fullStr |
Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) |
title_full_unstemmed |
Improved knowledge of high latitude ocean circulation with Synthetic Aperture Radar (ISAR) |
title_sort |
improved knowledge of high latitude ocean circulation with synthetic aperture radar (isar) |
publisher |
Zenodo |
publishDate |
2018 |
url |
https://doi.org/10.5281/zenodo.7414314 |
genre |
Nordic Seas |
genre_facet |
Nordic Seas |
op_relation |
https://zenodo.org/communities/nersc-research https://doi.org/10.5281/zenodo.7414313 https://doi.org/10.5281/zenodo.7414314 oai:zenodo.org:7414314 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.5281/zenodo.741431410.5281/zenodo.7414313 |
_version_ |
1810458863583887360 |