Abstract
The retrieval of ocean wave spectra from SAR images is a challenging problem because the imaging mechanism is nonlinear, the image spectrum contains contributions of speckle noise, and the interpretation of a SAR image as a single snapshot in time causes directional ambiguities. We present a new wave retrieval methodology that overcomes these problems to a significant extent by utilizing spotlight-mode SAR images from TerraSAR-X and COSMO-SkyMed in combination with advanced subaperture processing. The long integration times of spotlight-mode images enable us to derive time series of subaperture images for periods of up to a few seconds, which show the propagation directions and speeds of moving patterns. Then we can use Fourier analysis and a filter based on the known dispersion relation of ocean waves to separate actual ocean wave signatures in the data from other contributions. This process is phase-preserving and lets us reconstruct short "videos" of the spatio-temporal evolution of the ocean wave signatures during the SAR overpass, which are easier to invert into surface slope and elevation fields and the corresponding wave spectra than conventional SAR intensity images.
| Original language | English (US) |
|---|---|
| Title of host publication | EUSAR 2018 - 12th European Conference on Synthetic Aperture Radar, Proceedings |
| Publisher | Institute of Electrical and Electronics Engineers Inc. |
| Pages | 1320-1321 |
| Number of pages | 2 |
| Volume | 2018-June |
| ISBN (Electronic) | 9783800746361 |
| State | Published - Jan 1 2018 |
| Event | 12th European Conference on Synthetic Aperture Radar, EUSAR 2018 - Aachen, Germany Duration: Jun 4 2018 → Jun 7 2018 |
Other
| Other | 12th European Conference on Synthetic Aperture Radar, EUSAR 2018 |
|---|---|
| Country | Germany |
| City | Aachen |
| Period | 6/4/18 → 6/7/18 |
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ASJC Scopus subject areas
- Signal Processing
- Instrumentation
Cite this
Advanced ocean wave retrieval from time series of spotlight SAR subaperture images. / Romeiser, Roland; Graber, Hans C.
EUSAR 2018 - 12th European Conference on Synthetic Aperture Radar, Proceedings. Vol. 2018-June Institute of Electrical and Electronics Engineers Inc., 2018. p. 1320-1321.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Advanced ocean wave retrieval from time series of spotlight SAR subaperture images
AU - Romeiser, Roland
AU - Graber, Hans C
PY - 2018/1/1
Y1 - 2018/1/1
N2 - The retrieval of ocean wave spectra from SAR images is a challenging problem because the imaging mechanism is nonlinear, the image spectrum contains contributions of speckle noise, and the interpretation of a SAR image as a single snapshot in time causes directional ambiguities. We present a new wave retrieval methodology that overcomes these problems to a significant extent by utilizing spotlight-mode SAR images from TerraSAR-X and COSMO-SkyMed in combination with advanced subaperture processing. The long integration times of spotlight-mode images enable us to derive time series of subaperture images for periods of up to a few seconds, which show the propagation directions and speeds of moving patterns. Then we can use Fourier analysis and a filter based on the known dispersion relation of ocean waves to separate actual ocean wave signatures in the data from other contributions. This process is phase-preserving and lets us reconstruct short "videos" of the spatio-temporal evolution of the ocean wave signatures during the SAR overpass, which are easier to invert into surface slope and elevation fields and the corresponding wave spectra than conventional SAR intensity images.
AB - The retrieval of ocean wave spectra from SAR images is a challenging problem because the imaging mechanism is nonlinear, the image spectrum contains contributions of speckle noise, and the interpretation of a SAR image as a single snapshot in time causes directional ambiguities. We present a new wave retrieval methodology that overcomes these problems to a significant extent by utilizing spotlight-mode SAR images from TerraSAR-X and COSMO-SkyMed in combination with advanced subaperture processing. The long integration times of spotlight-mode images enable us to derive time series of subaperture images for periods of up to a few seconds, which show the propagation directions and speeds of moving patterns. Then we can use Fourier analysis and a filter based on the known dispersion relation of ocean waves to separate actual ocean wave signatures in the data from other contributions. This process is phase-preserving and lets us reconstruct short "videos" of the spatio-temporal evolution of the ocean wave signatures during the SAR overpass, which are easier to invert into surface slope and elevation fields and the corresponding wave spectra than conventional SAR intensity images.
UR - http://www.scopus.com/inward/record.url?scp=85050491724&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050491724&partnerID=8YFLogxK
M3 - Conference contribution
VL - 2018-June
SP - 1320
EP - 1321
BT - EUSAR 2018 - 12th European Conference on Synthetic Aperture Radar, Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
ER -