1. Australian Antarctic Data Centre
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4. ASAC_1219_AAT_NI_ADPE_Colonies

Description

An ArcGIS shapefile layer showing the extent of all extant Adelie penguin (Pygoscelis adeliae) colonies at Nelly Island, Windmill Islands, December, 1990.

The colony boundaries were digitised from Linhof aerial photographs (ANTC1219, run 53, frames 5-7) that were georeferenced to the Windmill Islands Topopoly GIS dataset.

Data quality cannot be accurately assessed. Errors in the georeferencing process could not be quantified, and there are positional discrepancies between overlapping aerial photographs are up to 2.4 m. Thus, absolute errors in the position of the colonies cannot be quantified, but the colony boundaries should be within ~0.5m of their location within the photographs.

The shapefile and the georeferenced aerial photographs are available for download from a Related URL.

This work was completed as part of ASAC project 1219 (ASAC_1219).

Quality

The positional accuracy of this dataset cannot be fully assessed. It was created by georeferencing aerial photographs to the Windmill Islands Topopoly Dataset and then digitising the colonies in those photographs.

The metadata for the Windmill Islands Topopoly Dataset states: 'Owing to surface conditions at the time of the photography some small features may not be present or may be incorrectly shaped. These data are based on 1:30,000, 1:15,000 and 1:5000 scale aerial photography (film ANTC1000 - 1004) using a Zeiss UMK camera. The data was checked for correct topology and to ensure that the layers overlap and abut as appropriate. Where features were sourced from Antarctic Division aerial photography the horizontal and vertical accuracy of well defined features is 1 metre. The data conforms to the Australian Antarctic Spatial Data Model which includes Data Quality Indicators.'

The affine transformation used to georeference the photographs resulted in discrepancies between overlapping photographs of up to 2.4m. There may be additional errors in the georeferencing that cannot be assessed due to the differences in scale between the photographs and the available coastline layer. Thus, absolute errors in the position of the colonies cannot be quantified, but the colony boundaries should be within ~0.5m of their location within the photographs.

Access

These data are available for download from the provided URL.

Temporal Coverages

• Start date: 1990-12-17 - Stop date: 1990-12-17

Spatial Coverages

Data Resolution

Science Keywords

• EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES > BIRDS > PENGUINS

Use Constraints

This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1219_AAT_NI_ADPE_Colonies when using these data.