Abstract
It has been demonstrated that Along Track Interferometric (ATI) SAR is a useful tool to retrieve ocean surface currents. The ATI SAR provides an interferometric phase (hereafter called phase) which is directly related to the Line-Of-Sight (LOS) component of the surface velocity. The accuracy of ocean currents retrieval is highly dependent on the phase processing. For instance, a properly processed phase must equal zero over static targets. The measured TanDEM-X phase rarely (if ever) satisfies this condition which indicates a phase offset independent of the surface properties. The offset can be either due to a phase synchronization issue or to using inaccurate orbital and attitude information in the processing. The objective of phase calibration is the estimation and the removal of the offset and possible trends from the measured phase. In this paper, the topographic phase is simulated using a Digital Elevation Model (DEM) and baseline information. The calibration is carried out by estimating the average of the phase over land, after topography correction, and subtracting the estimated value from the measured phase. Finally, the residual phase trend is removed using a second order polynomial fitting.
| Original language | English (US) |
|---|---|
| Title of host publication | 2017 IEEE International Geoscience and Remote Sensing Symposium |
| Subtitle of host publication | International Cooperation for Global Awareness, IGARSS 2017 - Proceedings |
| Publisher | Institute of Electrical and Electronics Engineers Inc. |
| Pages | 922-925 |
| Number of pages | 4 |
| Volume | 2017-July |
| ISBN (Electronic) | 9781509049516 |
| DOIs | |
| State | Published - Dec 1 2017 |
| Event | 37th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2017 - Fort Worth, United States Duration: Jul 23 2017 → Jul 28 2017 |
Other
| Other | 37th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2017 |
|---|---|
| Country | United States |
| City | Fort Worth |
| Period | 7/23/17 → 7/28/17 |
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Keywords
- ATI SAR
- Ocean current
- phase calibration
- TanDEM-X
ASJC Scopus subject areas
- Computer Science Applications
- Earth and Planetary Sciences(all)
Cite this
Phase calibration of TanDEM-X ATI-SAR data for sea surface velocity measurements. / Elyouncha, Anis; Eriksson, Leif E.B.; Romeiser, Roland; Ulander, Lars M.H.
2017 IEEE International Geoscience and Remote Sensing Symposium: International Cooperation for Global Awareness, IGARSS 2017 - Proceedings. Vol. 2017-July Institute of Electrical and Electronics Engineers Inc., 2017. p. 922-925 8127103.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Phase calibration of TanDEM-X ATI-SAR data for sea surface velocity measurements
AU - Elyouncha, Anis
AU - Eriksson, Leif E.B.
AU - Romeiser, Roland
AU - Ulander, Lars M.H.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - It has been demonstrated that Along Track Interferometric (ATI) SAR is a useful tool to retrieve ocean surface currents. The ATI SAR provides an interferometric phase (hereafter called phase) which is directly related to the Line-Of-Sight (LOS) component of the surface velocity. The accuracy of ocean currents retrieval is highly dependent on the phase processing. For instance, a properly processed phase must equal zero over static targets. The measured TanDEM-X phase rarely (if ever) satisfies this condition which indicates a phase offset independent of the surface properties. The offset can be either due to a phase synchronization issue or to using inaccurate orbital and attitude information in the processing. The objective of phase calibration is the estimation and the removal of the offset and possible trends from the measured phase. In this paper, the topographic phase is simulated using a Digital Elevation Model (DEM) and baseline information. The calibration is carried out by estimating the average of the phase over land, after topography correction, and subtracting the estimated value from the measured phase. Finally, the residual phase trend is removed using a second order polynomial fitting.
AB - It has been demonstrated that Along Track Interferometric (ATI) SAR is a useful tool to retrieve ocean surface currents. The ATI SAR provides an interferometric phase (hereafter called phase) which is directly related to the Line-Of-Sight (LOS) component of the surface velocity. The accuracy of ocean currents retrieval is highly dependent on the phase processing. For instance, a properly processed phase must equal zero over static targets. The measured TanDEM-X phase rarely (if ever) satisfies this condition which indicates a phase offset independent of the surface properties. The offset can be either due to a phase synchronization issue or to using inaccurate orbital and attitude information in the processing. The objective of phase calibration is the estimation and the removal of the offset and possible trends from the measured phase. In this paper, the topographic phase is simulated using a Digital Elevation Model (DEM) and baseline information. The calibration is carried out by estimating the average of the phase over land, after topography correction, and subtracting the estimated value from the measured phase. Finally, the residual phase trend is removed using a second order polynomial fitting.
KW - ATI SAR
KW - Ocean current
KW - phase calibration
KW - TanDEM-X
UR - http://www.scopus.com/inward/record.url?scp=85041857378&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041857378&partnerID=8YFLogxK
U2 - 10.1109/IGARSS.2017.8127103
DO - 10.1109/IGARSS.2017.8127103
M3 - Conference contribution
VL - 2017-July
SP - 922
EP - 925
BT - 2017 IEEE International Geoscience and Remote Sensing Symposium
PB - Institute of Electrical and Electronics Engineers Inc.
ER -