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Staff from the National Snow and Ice Data Center (NSIDC) and the University of New Hampshire assembled the MODIS Mosaic of Antarctica (MOA) Image Map (2003-2004), which consists of two cloud-free digital image maps that show mean surface morphology and a quantatative measure of optical snow grain size on the Antarctic continent and surrounding islands. The 260 orbit swaths used to create the 2003/2004 MOA Surface Morphology Image Map and the 2003/2004 MOA Grain Size Image Map were acquired between 20 November 2003 and 29 February 2004 by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board the NASA EOS Aqua and Terra satellites. The 122 orbit swaths used to create the 2003 MOA Grain Size Image Map were acquired between 1 November 2003 and 17 December 2003. Vector data sets with the corresponding coastlines, ice sheet grounding lines, and islands are also provided.
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
We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.
Haran, T., J. Bohlander, T. Scambos, and M. Fahnestock. 2005, updated 2013. MODIS Mosaic of Antarctica (MOA) Image Map. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5ZK5DM5.
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.