Investigation of ICESat-2 and Landsat/Sentinel-2 Imagery Fusion for Retrieval of Nearshore Bathymetry
Abstract
Continuous and temporally updated bathymetry is crucial for understanding coastal processes. However, current passive remote sensing methods suitable for comprehensive bathymetry require in situ depth measurements to constrain results, which can be costly in remote and restricted areas. To address this issue we investigated the fusion of data from two satellite platforms. The first platform is the Advanced Topographic Laser Altimeter System (ATLAS) aboard the recently launched NASA ICESat-2 satellite, which is equipped with a green 532-nm laser that has been shown to generate returns up to 38-m depth in optically clear waters. The second platform is multispectral satellite imagery from either Landsat or Sentinel-2. ICESat-2 has a 91-day orbital period and 3.3-km beam spacing that is insufficient for mapping high resolution bathymetry by itself. Furthermore, multispectral imagery has wide spatial coverage that is unable to resolve bathymetry without known depth constraints. When combined, the depths measured by ICESat-2 can be used to seed satellite derived bathymetry algorithms and thereby allow for widespread and repeated remotely sensed nearshore bathymetry. Data collected over the nearshore in Destin, FL offer a proof of concept for this approach. Depth profiles were observed during a pass of ICESat-2 in November 2018 and are compared to airborne lidar data collected by NOAA's Coastal Zone Mapping and Imaging Lidar (CZMIL) system in October 2018. Extracted depth profiles are then used to make bathymetric maps using concurrent Landsat and Sentinel-2 images. These results are spatially compared to the airborne lidar data to assess overall accuracy, using both linear regression and support vector regression methods for bathymetric inversion.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C31C1545A
- Keywords:
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- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES;
- 0726 Ice sheets;
- CRYOSPHERE;
- 0750 Sea ice;
- CRYOSPHERE;
- 4556 Sea level: variations and mean;
- OCEANOGRAPHY: PHYSICAL