Abstract:
Aerial survey of the Gold Harbour elephant seal colony, Mirounga leonina, during the 2023/24 season conducted using a fixed-wing remotely piloted aerial system (RPAS).
The aerial survey was conducted as part of the Darwin Plus (DPLUS) 214 project: Southwest Atlantic Elephant Seal Population Assessment (SAESPA).
Dataset includes the original images and log files, post-processed imagery data, along with the resulting georeferenced DSM (digital surface model) and an orthorectified mosaic of the imagery.
This dataset is from flight number DPLUS_214_32 which was carried out on 2024-11-10.
This work was supported by the Overseas Territories Environment and Climate Fund under Grant Darwin Plus ref: DPLUS214: Southwest Atlantic Elephant Seal Population Assessment (SAESPA).
Keywords:
South Georgia, aerial survey, digital surface model, drone, elephant seal, orthorectified mosaic
Fenney, N., Coleman, J., & Bamford, C. (2025). Aerial survey of Gold Harbour, South Georgia, elephant seal colony during the 2023/24 season, flight DLPUS_214_32 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/47d0718d-7146-44d3-965c-60e62a48b8cc
| Access Constraints: | Data under embargo until 2026-06-31. |
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| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2025-01-27 |
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| Dataset Progress: | Planned |
| Dataset Language: | English |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Mr Nathan Fenney |
| Role(s) | Investigator, Technical Contact |
| Organisation | British Antarctic Survey |
| Name | Jamie Coleman |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Dr Connor C G Bamford |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Reference: | ||
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| Quality: | Coordinate reference system for outputs: Projection: UTM Zone 23S Horizontal datum: WGS84 Vertical datum: MSL (mean sea level), EGM2008 geoid Resolution of final outputs: DSM (2.1 cm) Orthorectified mosaic (2.1 cm) The camera is placed in the centre of the central component of the drone, with the LiDAR ground sensor immediately below it and offset from the camera. The GNSS antenna is at the front of the drone, offset in the opposite direction. The sampling rate varied throughout the flight, depending on the speed of the platform. Calibration was accounted for in processing. |
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| Lineage/Methodology: | Data collection: Aerial survey conducted using a RPAS (AgEagle eBee X). The survey consisted of collecting overlapping imagery of the target area, with a forward overlap of 95%. The target altitude during acquisition was 95 m AGL (above ground level). Photogrammetry / final outputs: Structure from motion photogrammetry was used to determine the exterior orientation (x, y, z, omega, phi and kappa (or roll, pitch, yaw)) of the camera during image acquisition using a combination of the onboard GNSS solution and common points within the images. Once the camera centre and orientation for each image was determined, a dense point cloud was extracted of the surface within the target area. The dense point cloud was then transformed into a DSM (in metres), which in turn was used to resample the images onto a map projection, removing camera perspective and terrain distortions, in a process called ortho-rectification and resulted in a single complete mosaic of the imagery. |
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| Temporal Coverage: | |
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| Start Date | 2024-11-10 |
| End Date | 2024-11-10 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -54.45722 |
| Northernmost | -54.42987 |
| Longitude | |
| Westernmost | -36.20312 |
| Easternmost | -36.1537 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Gold Harbour, South Georgia |
| Data Collection: | Data collection equipment: Fixed-wing unmanned aerial vehicle (UAV): Manufacturer: AgEagle Model: eBee X Sensor: AgEagle SODA 3D Flight management software: eMotion (version 3.23.0) Post-flight processing software: eMotion (version 3.23.0) Photogrammetry software: Pix4D (version 4.9.0.). |
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| Data Storage: | Data is archived using the following structure. Total size: 6.40 GB. DPLUS_214_sortie number (e.g. DLPUS_214_01) 01_flight data: imagery. Image files (.jpg). Each file follows the same naming convention. For example, image file IX-12-29034_0069_0001.jpg refers to the platform ID (IX-12-29034 ), the sortie number (0069), the image number (0001) and the file extension (.jpg). 01_flight data: logs. UAV log files (.bb3). Each file follows the same naming convention. For example, log file IX-12-29034_0069_part001.bb3 refers to the platform ID (IX-12-29034 ), the sortie number (0069), the part number (part001) and the file extension (.bb3). These files are binary and can be opened in eMotion, by AgEagle / SenseFly. 02_post_flight_output: emotion_output/img for the PPK processed image files (.jpg). Each file follows the same naming convention. For example, image file IX-12-29034_0069_0001.jpg refers to the platform ID (IX-12-29034 ), the sortie number (0069), the image number (0001) and the file extension (.jpg). 02_post_flight_output: emotion_output for the PPK processed camera centres (.txt). Each file follows the same naming convention. For example, file IX-12-29034_0069_emotion_geoinfo.txt refers to the platform ID (IX-12-29034 ), the sortie number (0069), program name (emotion), information type (geoinfo) and the file extension (.txt). 03_final_outputs: dsm. Final digital surface model files (.tif, .tfw, .prj). Each file follows the same naming convention. For example, file IX-12-29034_0069_dsm.tif refers to the platform ID (IX-12-29034 ), the sortie number (0069), data type (dsm) and the file extension (.tif). 03_final_outputs: ortho. Final orthorectified moasic files (.tif, .tfw, .prj). Each file follows the same naming convention. For example, file IX-12-29034_0069_transparent_mosaic_group1.tif refers to the platform ID (IX-12-29034), the sortie number (0069), data type (transparent_mosaic_group1) and the file extension (.tif). |
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