DOI: 10.1594/pangaea.804588
title: Classified Adélie penguin colonies from Landsat data

description: Breeding distribution of the Adelie penguin, Pygoscelis adeliae, was surveyed with Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data along the coastline of Antarctica, an area covering approximately 330° of longitude. An algorithm was designed to minimize the radiometric contribution from exogenous sources and to retrieve Adelie penguin colony location and spatial extent from the ETM+ data. In all, 9143 individual pixels were classified as belonging to an Adelie penguin colony class out of the entire dataset of 195 ETM+ scenes, where the dimension of each pixel is 30 m by 30 m, and each scene is approximately 180 km by 180 km. Pixel clustering identified a total of 187 individual Adelie penguin colonies, ranging in size from a single pixel (900 m**2) to a maximum of 875 pixels (0.788 km**2). Colony retrievals have a very low error of commission, on the order of 1 percent or less, and the error of omission was estimated to be 2.9 percent by population based on comparisons with direct observations from surveys across east Antarctica. Thus, the Landsat retrievals can successfully locate Adelie penguin colonies that account for ~97 percent of a regional population. Geographic coordinates and the spatial extent of each colony retrieved from the Landsat data are available publically. Regional analysis found several areas where the Landsat retrievals suggest populations that are significantly larger than published estimates. Six Adelie penguin colonies were found that are believed to be unreported in the literature.
description: This data set lists each pixel classified as belonging to the Adélie penguin colony class, and includes the following parameters: a unique identification number for each colony cluster, the source ETM+ file for each pixel, an index of the "goodness" of the classification, the pixel row and column number of the source file, the geographic location of each classified pixel (in both polar stereographic and geographic latitude and longitude), the pixel rotation with respect to true north, and the at-instrument reflectance measured in ETM+ bands 3,4,5 and 7 for each pixel in the data set.PARAMETER DESCRIPTIONScolony_ID: Schwaller, Southwell and Emmerson describe the spatial clustering method applied to the dataset that resulted in 189 distinct Adelie penguin colonies. This field contains the ID numbers of the Adelie penguin colonies that resulted from the clustering as described in the paper.source_file: The file name of the Landsat-7 image that was the source of the classified pixel. The Landsat-7 images are archived by the US Geological Survey's Landsat Data Processing System, Sioux Falls, South Dakota. In the source file name, if L is counted as character 1, characters 4-6 are the scene path number, characters 7-9 are the scene row number, characters 10-13 are the year the scene was collected, and characters 14-16 are the Julian day the scene was collected.d-value: An index value of the "goodness" of the pixel classification. A d-value of 0 indicates an ideal classification of a pixel as a Adelie penguin colony. Values of d&gt;1.0 are classified as "not part of an Adelie penguin colony" class. See Schwaller, Southwell and Emmerson for details.row: The row number (starting from 0) of the pixel in the Landsat-7 source file.column: The column number (starting from 0) of the pixel in the Landsat-7 source file.northing: Polar Stereographic northing coordinate in meters of the pixel center based on the Radarsat Antarctic Mapping Project (RAMP) projection.easting: Polar Stereographic easting coordinate in meters of the pixel center based on the Radarsat Antarctic Mapping Project (RAMP) projection.latitude: Geographic latitude with decimal degrees of the pixel center using the WGS84 projection. Negative values indicate south latitude.longitude: Geographic longitude with decimal degrees of the pixel center using the WGS84 projection. Positive values indicate east longitude.rotation: Because of the geometry of the Landsat-7 satellite orbit, the top of a given scene is rotated with respect to true north depending on the longitude of the scene. Thus the corner points of a 30x30 meter pixel will also rotate with respect to true north depending on the scene location. This field is the value of the rotation about the pixel's center point coordinates with respect to true north. Negative values are rotated counter-clockwise from true north in degrees. Positive values are rotated clockwise from true north in degrees.band3: Landsat-7 ETM+ at-instrument reflectance in Band-3 (0.63 to 0.69 micrometers). Values range from 0 to 1.band4: Landsat-7 ETM+ at-instrument reflectance in Band-4 (0.77 to 0.90 micrometers). Values range from 0 to 1.band5: Landsat-7 ETM+ at-instrument reflectance in Band-5 (1.55 to 1.75 micrometers). Values range from 0 to 1.band7: Landsat-7 ETM+ at-instrument reflectance in Band-7 (2.09 to 2.35 micrometers). values range from 0 to 1.
description: Supplement to: Schwaller, Mathew R; Southwell, C J; Emmerson, L (2013): Continental-scale mapping of Adélie penguin colonies from Landsat imagery. Remote Sensing of Environment, 139, 353-364