Medium resolution vector contours for Antarctica

• Main Authors: Gerrish, Laura, Fretwell, Peter, Cooper, Paul
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2020
• Subjects: "EARTH SCIENCE","LAND SURFACE","TOPOGRAPHY","TERRAIN ELEVATION","CONTOUR MAPS"; "EARTH SCIENCE","LAND SURFACE","TOPOGRAPHY"; Antarctic Digital Database; Antarctica; Elevation; Topographic mapping; Antarctic; The Antarctic; Antarctic Peninsula; Balleny Islands; Antarc*; Norwegian Polar Institute
• Online Access: https://dx.doi.org/10.5285/0779002b-b95d-432f-b035-b952c36aa5c9; https://data.bas.ac.uk/items/0779002b-b95d-432f-b035-b952c36aa5c9

A continuous, smoothed contour dataset at 500 m intervals for all land south of 60S, excluding the Balleny Islands. The vertical datum of the contours is EGM2008. Contours are extracted primarily from the PGC Reference Elevation Model of Antarctica (REMA) v1.1 with certain islands filled from Copernicus WorldDEM. Peter I Oy contours are from the Norwegian Polar Institute. Sources of individual line segments are contained in the attribute table and full compilation information is given in the lineage statement. : All processing described here was performed in ArcGIS Pro version 2.6. A composite Digital Elevation Model (DEM) was created comprising of three datasets from the Reference Elevation Model of Antarctica v1.1: REMA_100m_peninsula_dem_filled, REMA_100m_dem and REMA_200m_dem_filled. These DEMs were first converted from ellipsoidal height to height above EGM2008 geoid and then mosaicked together in respective order at 100 m spatial resolution. This 100 m DEM was smoothed by performing Focal Statistics using a 40x40 cell size. 500 m contours were extracted and all contours with a height <1m were deleted, as well as erroneous offshore contours. In certain locations, primarily some islands on the Antarctic Peninsula, REMA data was insufficient to produce contours. In these places, contours were produced from the 'Copernicus WorldDEM 90m' DEM and smoothed by 4 km using a PAEK smoothing algorithm. Contours for Peter I y were incorporated from the Norwegian Polar Institute Data at 100 m intervals: 500 m intervals were extracted and smoothed by 800 m, to match the appropriate resolution of the main contours. All contours were merged together and lines <5 km in length were deleted. Further lines <20 km were deleted in non-mountainous regions, so as to avoid deleting small mountain peak contours but to still simplify the main dataset. These regions were interpreted manually using the hillshade of the DEM used to produce the contours.