Transcripts of 4308_Tiling_Greenland_youtube_hq

Hi. I'm Cindy Starr. At NASA 's Scientific Visualization Studio we work with many Earth science datasets that must be accurately positioned on a globe. For example, we obtained 30-meter topography data for Greenland along with an ocean and an ice sheet mask from the Greenland Ice Mapping Project at Ohio State. Each of these datasets consists of a 6 x 6 array of 124 megapixel tiles. We also received seven sets of 20-meter Radarsat data from the Canadian Space Agency, mosaicked at the University of Washington's Applied Physics Lab. Each set consist of a 5 x 5 array of 421 megapixel tiles. We developed an IDL routine that extracts the coordinate and projection information from geo-tif images and writes out RSL include files that pass the parameters to a projection routine. The projection routine is a C++ Renderman plugin that computes the projection calculations in double precision and accurately positions the related texture tile. Parameters to the projection plugin are passed in string format in order to provide double precision accuracy. We employed this method with the high-resolution Greenland data, accurately mapping 87 gigapixels of data.