Performance Analysis of Ocean Surface Topography Altimetry by Ku-Band Near-Nadir Interferometric SAR
Abstract
:1. Introduction
2. Altimetry Simulation of OST
2.1. System Parameters of InIRA
2.2. Altimetry Principle of OST
2.3. Altimetric Precision Simulation
3. OST Altimetry Results and Analysis of InIRA
3.1. Interferometric Data Processing
3.2. Altimetric Precision Estimation
4. Discussion
5. Conclusions
- (1)
- According to the intensity boundary phenomenon, the available swath of high altimetric precision will be narrower than expected. As for InIRA, when the incidence range is 1°~5°, the swath will decrease to only 20 km. This narrow swath can hardly fulfill the altimetry on sub-mesoscale oceanic processes. Therefore, future near-nadir InSAR could fly on a higher orbit to increase the swath width.
- (2)
- Flying on a higher orbit means the SNR of the received signal will decrease significantly, thereby definitely increasing the phase noise level. As mentioned before, multi-looking is one of the most effective ways to lower the phase noise, and the 3-cm altimetric precision on a 10-km grid is much higher than that of a 1-km grid, according to the simulation. However, it is quite challenging for the 10-km grid to resolve mesoscale or sub-mesoscale oceanic processes whose physical dimension is only about 15~300 km. Therefore, future near-nadir InSAR should guarantee an even higher intrinsic image resolution so that a larger multi-look number could be acquired on the same grid.
- (3)
- Baseline length is the key parameter which guarantees high altimetric precision for near-nadir InSAR. Meanwhile, a longer baseline will mitigate the stringent requirement for a systematic phase noise level and data processing precision, allowing the near-nadir InSAR to achieve better performance much more easily.
Supplementary Materials
Supplementary File 1Acknowledgments
Author Contributions
Conflicts of Interest
References
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Kong, W.; Chong, J.; Tan, H. Performance Analysis of Ocean Surface Topography Altimetry by Ku-Band Near-Nadir Interferometric SAR. Remote Sens. 2017, 9, 933. https://doi.org/10.3390/rs9090933
Kong W, Chong J, Tan H. Performance Analysis of Ocean Surface Topography Altimetry by Ku-Band Near-Nadir Interferometric SAR. Remote Sensing. 2017; 9(9):933. https://doi.org/10.3390/rs9090933
Chicago/Turabian StyleKong, Weiya, Jinsong Chong, and Hong Tan. 2017. "Performance Analysis of Ocean Surface Topography Altimetry by Ku-Band Near-Nadir Interferometric SAR" Remote Sensing 9, no. 9: 933. https://doi.org/10.3390/rs9090933