Data may be held several times for the same lake and to record changes by year.
The data set was derived from numerous hardcopy maps, which involved four main processes. These were:
1, The hard copy maps were scanned and saved as TIF images. These images were then loaded into Corel Trace and the lines traced creating a DXF file. The DXF files were checked using ... Microstation for small tracing errors such as dangle arcs, and corrected where necessary.
2, The images of the hard copy maps were geo-referenced using Microstation and a similarity transformation. The images were fitted to the Vestfold Hills lake edge data using a visual best-fit approach with varying results.
3, Using the geo-referenced images, the DXF files were imported, and a similarity transformation was performed to fit the line data to the geo-referenced image. Once geo-referenced, all contour lines had their respective heights tagged.
4, The contour line data were then imported into the Arc/Info coverage format (utilising regions) and structured to conform with the Australian Antarctic Division's Spatial Data Model. This spatial data model has since been superseded by the SCAR Feature Catalogue (refer to link below) and the attribute data have been reformatted accordingly.
Each bathymetric contour and bathymetric area feature has a DQI number. Use these DQI numbers (173,175,182-184) to search for Quality Information Records about the features (refer to link below). Enter the DQI number as the Qinfo id and start the search. The information includes the original hard copy map name and the estimated accuracy of the data.
These data are publicly available for download from the provided URL.