Abstract:
Beaver Lake and Loewe Massif Features Mapped from SPOT 5 Imagery.
The purpose of this Australian Antarctic Data Centre project was to map features on and around Beaver Lake and the Loewe Massif using a rectified SPOT 5 satellite image. The image was captured on 11 January 2004. The features mapped were to be provided as a series of ArcInfo Coverages in Geographicals, conforming to the Feature Catalogue.
Further information is provided in a downloadable report at the URL given below.
A thumbnail of the image (ID number 167) is available via the Australian Antarctic Data Centre's Satellite Image Catalogue at the URL given below.
Quality
The features were mapped from SPOT 5 Imagery. An unsupervised classification was run on the image to create distinct grey scale values. An automated feature extraction process was then performed in ERDAS Imagine to automatically select and extract a range of features, including Glacier, Rock, Snow and Water Storage polygon boundaries and Cliff, Escarpment, Ridge and Water Course lines. These ... areas were then compared with the true colour image, in ESRI's ArcGIS, and the boundaries were supplemented with manual digitising techniques where necessary.
All other feature types were also mapped in ESRI's ArcGIS by tracing along and around features using a stream digitising technique. Relevant linear features were then polygonised. The datasets were converted to double precision ArcInfo Coverages in UTM Zone 42. ESRI's ArcGIS Desktop and Workstation were used to process the vector data. The features which had been automatically extracted from the image were generalised and the lines were splined with a grain tolerance of 3m to smooth them. The line feature coverages were cleaned with a tolerance of 0.1m. ArcEdit was then used to tidy the line work in the resultant coverage. Arcs were extended where required and overshoots were deleted.
The resultant coverages were built for line and polygon topology. The polygons were attributed using the SPOT 5 image as a backdrop. The features were then extracted into separate feature coverages.
The data were attributed according to the AADC Feature Type Catalogue. The individual feature coverages were built and checked for errors. A further visual check was then performed to check the features corresponded to the image.
The accuracy of the mapping was within +/- 7.5m for 95% of mapped features (3 pixels in the image). This is a positional accuracy within the image. The individual feature coverages were projected to Geographicals (WGS84).
Access Constraints
A pdf copy of a report containing further information is available for download from the provided URL.
The satellite image itself has limited availability. Contact the investigator for access.
A thumbnail of the satellite image and details are available via the Satellite Image Catalogue. See the provided URL.
Please follow instructions listed in the citation reference at the provided URL when using these data.
This
"Beaver Lake and Loewe Massif Features Mapped from SPOT 5 Imagery." is licensed under a Creative Commons Attribution 3.0 Unported License.
