Bathymetry of Approaches to Mawson Station

Brief description

Bathymetric contours and height range polygons of approaches to Mawson Station, derived from RAN Fair sheet, Aurora Australis and GEBCO soundings.

Lineage

Progress Code: completed

Statement: All soundings from fair sheets Approaches to Mawson, sheets HI 99 V5/425 6762/1 (Sheet 3) Scale 1:10,000 HI 99 V5/425 6762/2 (Sheet 2) Scale 1:25,000 HI 169 V5/516 6762/3 (Sheet 2) Scale 1:5000 were captured and all GEBCO and Aurora Australis data were used. Point data taken RAN Fair Sheets (see their Metadata records) and integrated with GEBCO and Aurora Australis Point data. The entire dataset was contoured using Intergraph's Siteworks with an interval of 5 metres in areas of scale 1:10000 to 1:25000; 2 metres in areas of 1:5000 scale; and 200 metres in areas of much smaller scale (GEBCO and Aurora Australis). Resulting contour lines were converted to arc/Info and checked for overlapping lines. These were fixed where they occurred. The ends of the contours were closed using connectors and the resulting dataset was built for polygons. The contour height values were transferred to the polygon tables. Depressions were determined by isolating closed polygons (without connectors), if these contained contours which went below the height range of the surrounding contours then they were tagged as depressions. Feature values for polygons were also determined from their surrounding lines. The final dataset was subdivided into Data Quality Indicator (DQI) regions so that the polygons and arcs could be tagged with the correct DQI value. DQI regions were assigned using the bounds of the most accurate dataset first and then working out to the least accurate dataset. The dataset was tested for spatial accuracy and data completeness. The attribute values were consistent with the topological relationships.