Data

Shark Bay Satellite-Derived Bathymetry Acquisition (20210029C)

Name: Shark Bay Satellite-Derived Bathymetry Acquisition (20210029C)
Published: 2023

Geoscience Australia

Lebrec, U. ; The University of Western Australia (UWA)

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ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=info:doi10.26186/149909&rft.title=Shark Bay Satellite-Derived Bathymetry Acquisition (20210029C)&rft.identifier=10.26186/149909&rft.publisher=Commonwealth of Australia (Geoscience Australia)&rft.description=The Shark Bay Bathymetry was derived form a time series of multispectral satellite data from the Copernicus Sentinel-2 satellite sensor, acquired between January 2017 and December 2020. This dataset was produced by the University of Western Australia to support student research projects. The dataset encompasses the Shark Bay in Western Australia. These critical geospatial data layers provide the essential environmental baseline information for the long-term monitoring and management. Mapping the shallow water zone is of importance both from an environmental and socioeconomic perspective. Bathymetry data was processed following the workflow of Lebrec et al. (2021) [https://doi.org/10.5194/essd-13-5191-2021]. This dataset is not to be used for navigational purposes. This dataset is published with the permission of the CEO, Geoscience Australia.Maintenance and Update Frequency: asNeededStatement: AusSeabed follows the recommended processing methodology as prescribed by the AusSeabed Multibeam Guidelines (https://australian-multibeam-guidelines.github.io/). Please note that certain products are subject to routine update (e.g. resolution, coverage, temporal variation, guidelines/best practice). The client is advised to refer to the latest version of all documents and products for the most up-to-date material. For eCat records the version is expressed in the record title whilst products incorporate date of production as per AusSeabed’s file naming convention.The Shark Bay satellite-derived bathymetry was produced in 2021 at The University of Western Australia to support student research projects. The dataset was processed following the workflow of Lebrec et al. (2021) using 673 Sentinel 2 satellite images acquired between January 2017 and December 2020. The dataset includes a digital elevation model as well as an image count grid and a standard deviation grid with a spatial resolution of 10 m. Survey metadata:The satellite-derived bathymetry (SDB) was acquired by the following survey:· Dataset name: Shark Bay Satellite-derived bathymetry.· Institution: The University of Western Australia.· Country: Australia.· Sensor: Sentinel-2· Start date (Sentinel-2 satellite images): January 2017· End date (Sentinel-2 satellite images): December 2020· Year of production of the bathymetry: 2021.· Depth range: +5 to -30 meters (Depth negative).· Coverage: 14,450 km2 (calculated using UTM49 projection).· Number of grids: 3 (DEM, Count and STD).· Grids bin size: 10 x 10 metres. · Vertical accuracy: see note below.· Horizontal Datum: WGS84.· Vertical Datum: EGM2008.· Use Limitation: This dataset is not to be used for navigation.Processing methodology:The bathymetry data was processed following the workflow of Lebrec et al. (2021) [https://doi.org/10.5194/essd-13-5191-2021]. The main processing steps to produce this dataset can be summarised as follow:1. Data Selection: The bathymetry was created using 673 Sentinel 2 satellite images acquired between January 2017 and December 2020 with a grid resolution of 10 m. During this period, all images captured between August and January each year with less than 1% cloud cover were processed.2. Preliminary processing: A bathymetry file was produced for each of the 673 satellite images using the equation from Stumpf (2002) and calibration points from the Australian Hydrographic Office.3. Filtering: The resulting files were filtered and reviewed according to a coefficient of correlation calculated between AHO depth soundings and the image reflectance. A total of 505 images had a coefficient of correlation > 0.7 and were further reviewed manually to discard images containing significant artefacts. At the end of this step, 244 images were validated with an average coefficient of correlation of 0.85.4. Correction: All remaining images were corrected for regional changes in image reflectivity using an error model based on the integration of the AHO calibration points.5. Time stack: The final satellite-derived bathymetry data was calculated as the median value of all individual overlapping bathymetry files.Notes about the accuracy of the data.· The vertical accuracy of the Shark Bay satellite-derived bathymetry could not be precisely measured due to the lack of independent reference datasets. Instead, the mean standard deviation of the bathymetry (1.12 m) is used as an approximation of the vertical accuracy. · The bathymetry and standard deviation grids are supported by an image count raster. The raster displays, for each pixel, the number of images that were included in the final statistical analysis. The reliability of the data is expected to increase with the number of images.The data are locally heavily affected by seagrass meadows. In these areas, the morphology shown by the satellite-derived bathymetry may not represent the morphology of the seabed. These areas tend to have a granular pattern with intersecting channels appearing as relief rather than depressions. The workflow used here does not allow such artefacts to be filtered out.At Geoscience Australia, the received geotiff in MSL was shifted to EGM2008 using AusCoastVDT and CARIS HIPS and SIPS. The final processed grids were exported as a 32-bit floating point Geotiff at 10m resolution, referenced to EGM2008.DATA QUALITYThis dataset has been subject to independent post-production validation and testing. Tests have been performed for data completeness, correct spatial representation, attribute accuracy, logical consistency, metadata completeness and correctness, and where appropriate for compliance with Geoscience Australia's data dictionaries.Errors found in this dataset should be reported to:Corporate Data ManagerGeoscience AustraliaGPO Box 378Canberra ACT 2601, AustraliaEmail: [email protected] Errors will be rectified in subsequent data releases, if any.&rft.creator=Lebrec, U. &rft.creator=The University of Western Australia (UWA) &rft.date=2023&rft.coverage=westlimit=113.0099; southlimit=-26.68319; eastlimit=114.2242; northlimit=-24.37938; projection=WGS 84 / UTM zone 49S / projected (EPSG: 32749)&rft.coverage=westlimit=113.0099; southlimit=-26.68319; eastlimit=114.2242; northlimit=-24.37938; projection=WGS 84 / UTM zone 49S / projected (EPSG: 32749)&rft.coverage=uplimit=5; downlimit=-30; projection=EGM2008 height / vertical (EPSG: 3855)&rft.coverage=uplimit=5; downlimit=-30; projection=EGM2008 height / vertical (EPSG: 3855)&rft_rights=Creative Commons Attribution 4.0 International Licence https://creativecommons.org/licenses/by/4.0/&rft_rights=© The University of Western Australia 2023&rft_rights=Australian Government Security Classification System https://www.protectivesecurity.gov.au/Pages/default.aspx&rft_subject=geoscientificInformation&rft_subject=bathymetry&rft_subject=satellite-derived bathymetry (SDB)&rft_subject=bathymetric grids&rft_subject=AusSeabed&rft_subject=HVC_144641&rft_subject=Oceans&rft_subject=EARTH SCIENCES&rft_subject=Earth Science | Oceans | Bathymetry/Seafloor Topography | Bathymetry&rft_subject=Satellite-Derived Bathymetry&rft_subject=Published_External&rft.type=dataset&rft.language=English Access the data

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Full description

The Shark Bay Bathymetry was derived form a time series of multispectral satellite data from the Copernicus Sentinel-2 satellite sensor, acquired between January 2017 and December 2020. This dataset was produced by the University of Western Australia to support student research projects. The dataset encompasses the Shark Bay in Western Australia. These critical geospatial data layers provide the essential environmental baseline information for the long-term monitoring and management. Mapping the shallow water zone is of importance both from an environmental and socioeconomic perspective. Bathymetry data was processed following the workflow of Lebrec et al. (2021) [https://doi.org/10.5194/essd-13-5191-2021]. This dataset is not to be used for navigational purposes. This dataset is published with the permission of the CEO, Geoscience Australia.

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Maintenance and Update Frequency: asNeeded

Statement:

AusSeabed follows the recommended processing methodology as prescribed by the AusSeabed Multibeam Guidelines (https://australian-multibeam-guidelines.github.io/). Please note that certain products are subject to routine update (e.g. resolution, coverage, temporal variation, guidelines/best practice). The client is advised to refer to the latest version of all documents and products for the most up-to-date material. For eCat records the version is expressed in the record title whilst products incorporate date of production as per AusSeabed’s file naming convention.

The Shark Bay satellite-derived bathymetry was produced in 2021 at The University of Western Australia to support student research projects. The dataset was processed following the workflow of Lebrec et al. (2021) using 673 Sentinel 2 satellite images acquired between January 2017 and December 2020. The dataset includes a digital elevation model as well as an image count grid and a standard deviation grid with a spatial resolution of 10 m.

Survey metadata:

The satellite-derived bathymetry (SDB) was acquired by the following survey:

· Dataset name: Shark Bay Satellite-derived bathymetry.

· Institution: The University of Western Australia.

· Country: Australia.

· Sensor: Sentinel-2

· Start date (Sentinel-2 satellite images): January 2017

· End date (Sentinel-2 satellite images): December 2020

· Year of production of the bathymetry: 2021.

· Depth range: +5 to -30 meters (Depth negative).

· Coverage: 14,450 km2 (calculated using UTM49 projection).

· Number of grids: 3 (DEM, Count and STD).

· Grids bin size: 10 x 10 metres.

· Vertical accuracy: see note below.

· Horizontal Datum: WGS84.

· Vertical Datum: EGM2008.

· Use Limitation: This dataset is not to be used for navigation.

Processing methodology:

The bathymetry data was processed following the workflow of Lebrec et al. (2021) [https://doi.org/10.5194/essd-13-5191-2021]. The main processing steps to produce this dataset can be summarised as follow:

1. Data Selection: The bathymetry was created using 673 Sentinel 2 satellite images acquired between January 2017 and December 2020 with a grid resolution of 10 m. During this period, all images captured between August and January each year with less than 1% cloud cover were processed.

2. Preliminary processing: A bathymetry file was produced for each of the 673 satellite images using the equation from Stumpf (2002) and calibration points from the Australian Hydrographic Office.

3. Filtering: The resulting files were filtered and reviewed according to a coefficient of correlation calculated between AHO depth soundings and the image reflectance. A total of 505 images had a coefficient of correlation > 0.7 and were further reviewed manually to discard images containing significant artefacts. At the end of this step, 244 images were validated with an average coefficient of correlation of 0.85.

4. Correction: All remaining images were corrected for regional changes in image reflectivity using an error model based on the integration of the AHO calibration points.

5. Time stack: The final satellite-derived bathymetry data was calculated as the median value of all individual overlapping bathymetry files.

Notes about the accuracy of the data.

· The vertical accuracy of the Shark Bay satellite-derived bathymetry could not be precisely measured due to the lack of independent reference datasets. Instead, the mean standard deviation of the bathymetry (1.12 m) is used as an approximation of the vertical accuracy.

· The bathymetry and standard deviation grids are supported by an image count raster. The raster displays, for each pixel, the number of images that were included in the final statistical analysis. The reliability of the data is expected to increase with the number of images.

The data are locally heavily affected by seagrass meadows. In these areas, the morphology shown by the satellite-derived bathymetry may not represent the morphology of the seabed. These areas tend to have a granular pattern with intersecting channels appearing as relief rather than depressions. The workflow used here does not allow such artefacts to be filtered out.

At Geoscience Australia, the received geotiff in MSL was shifted to EGM2008 using AusCoastVDT and CARIS HIPS and SIPS. The final processed grids were exported as a 32-bit floating point Geotiff at 10m resolution, referenced to EGM2008.

DATA QUALITY

This dataset has been subject to independent post-production validation and testing. Tests have been performed for data completeness, correct spatial representation, attribute accuracy, logical consistency, metadata completeness and correctness, and where appropriate for compliance with Geoscience Australia's data dictionaries.

Errors found in this dataset should be reported to:

Corporate Data Manager

Geoscience Australia

GPO Box 378

Canberra ACT 2601, Australia

Email: [email protected]

Reported Errors will be rectified in subsequent data releases, if any.

Notes

Purpose
To derive bathymetry for the purpose of supporting the sustainable use of our marine environment and jurisdiction; strengthening our resilience to natural hazards and enabling location-based decisions and actions through best practice digital mapping, Earth observations and precise positioning

Created: 02 12 2023

Issued: 20 09 2024

Data time period: 2017-01-01 to 2020-12-31

This dataset is part of a larger collection

Click to explore relationships graph

text: westlimit=113.0099; southlimit=-26.68319; eastlimit=114.2242; northlimit=-24.37938; projection=WGS 84 / UTM zone 49S / projected (EPSG: 32749)

text: uplimit=5; downlimit=-30; projection=EGM2008 height / vertical (EPSG: 3855)

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Other Information

Shark Bay Satellite-Derived Bathymetry 2017 10m (zip) [587.6 MB]

url : https://files.ausseabed.gov.au/survey/Shark-Bay-Satellite-Derived-Bathymetry-2021-10m.zip External Link

Identifiers

DOI : 10.26186/149909
URL : pid.geoscience.gov.au/dataset/ga/149909
global : b007da9a-8cd0-44c0-96e9-c645a879d2e8