Staff from the National Snow and Ice Data Center (NSIDC) and the University of New Hampshire have assembled a digital image map and a snow-grain-size image of the Antarctic continent and surrounding islands. The Moderate Resolution Imaging Spectroradiometer (MODIS) Mosaic of Antarctica (MOA) image map is a composite of 260 swaths comprised of both Terra and Aqua MODIS images acquired between 20 November 2003 and 29 February 2004.
MOA provides a cloud-free view of the ice sheet, ice shelves, and land surfaces at a grid scale of 125 m and an estimated resolution of 150 m. All land areas south of 60° S that are larger than a few hundred meters are included in the mosaic. Also included are several persistent fast ice areas and grounded icebergs. MOA consists of two MODIS-derived image data sets: a digitally smoothed red-light image, which as compiled using Band 1; and a snow-grain-size image, which was compiled using the normalized difference of calibrated data from Band 1 and Band 2 data.
Images were destriped, georeferenced, and resampled using the MS2GT software available at NSIDC. Acquisition times were limited to 0500 - 1300 Universal Time continent-wide to provide a more uniform illumination direction of ice surface morphology across the image seams, while maintaining the ability to capture linear snow features of every orientation.
The 125 m grid images are identical to the Radarsat Antarctic Mapping Project Antarctic Mapping Mission 1 (RAMP AMM-1) 125 m mosaic. The MOA image map is complimentary to the radar-image-based RAMP mosaic, highlighting true surface morphology without a subsurface volume backscattering component. This results in a better discrimination between accumulation- and crevasse-related subsurface changes and surface features.
The digitally smoothed red-light images are available via FTP at two spatial grid scales: 750 m (112 MB) and 125 m (4 GB), and via a Web-based map server capable of creating manually-selected JPEG images (see the Map Server User's Guide). A variety of pre-processed contrast stretches are available for the JPEG images. The snow-grain-size images are available only at 750 m resolution via FTP. Image data on the FTP site include 16-bit images to preserve the radiometric content of the scenes.
Citing These Data
The following example shows how to cite the use of this data set in a publication. For more information, see our Use and Copyright Web page.
Haran, T., J. Bohlander, T. Scambos, T. Painter, and M. Fahnestock compilers. 2005, updated 2006. MODIS mosaic of Antarctica (MOA) image map. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.
The generation of this data set is discussed in the following article(s). Please acknowledge the use of this data set by referencing the following citation(s):
Scambos, T., T. Haran, M. Fahnestock, T. Painter, and J. Bohlander. 2007. MODIS-based Mosaic of Antarctica (MOA) data sets: continent-wide surface morphology and snow grain size. Remote Sensing of Environment 111(2): 242-257. 10.1016/j.rse.2006.12.020.
For more information on this data set, contact User Services at NSIDC.
| This is an example of a mosaic image at low resolution with an inset of the Steershead Ice Rise, showcasing the detail available through MOA.
This image, generated by combining the snow-grain-size image and the high-pass filtered Band 1 image in a Hue-Lightness-Saturation (HLS) transformation, shows a region of blue ice and coarse snow. The region contains the Queen Fabiola Mountains in East Antarctica. This was the site of a very large accumulation of meteorites deposited by ice flow and ablation on the blue ice surface.