id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc 6560,ASRP polar arc zone images are not correctly georeferenced,steveb,warmerdam,"When ASRP polar arc zone images are opened the affine transformation coefficients are not set correctly. The cell size is always set to 500m and the image origin to (-1152000, 1152000). The following method can be used to calculate the affine transformation coefficients for polar arc zone images: {{{ if( ZNA == 9) { // North Polar Case padfGeoTransform[0] = 111319.4907933 * (90.0 – PSO/3600.0) * sin(LSO * PI / 648000.0); padfGeoTransform[1] = 40075016.68558 / ARV; padfGeoTransform[2] = 0.0; padfGeoTransform[3] = -111319.4907933 * (90.0 – PSO/3600.0) * cos(LSO * PI / 648000.0); padfGeoTransform[4] = 0.0; padfGeoTransform[5] = -40075016.68558 / ARV; } else if (ZNA == 18) { // South Polar Case padfGeoTransform[0] = 111319.4907933 * (90.0 + PSO/3600.0) * sin(LSO * PI / 648000.0); padfGeoTransform[1] = 40075016.68558 / ARV; padfGeoTransform[2] = 0.0; padfGeoTransform[3] = 111319.4907933 * (90.0 + PSO/3600.0) * cos(LSO * PI / 648000.0); padfGeoTransform[4] = 0.0; padfGeoTransform[5] = -40075016.68558 / ARV; } }}} The method used is based on a sphere of radius 6378137m in accordance with the ASRP specification. In addition the polar zone coordinate system definitions will need to be modified as follows: {{{ if( ZNA == 9 ) { osSRS = ""PROJCS[\""ARC_System_Zone_09\"",GEOGCS[\""GCS_Sphere\"",DATUM[\""D_Sphere\"",SPHEROID[\""Sphere\"",6378137.0,0.0]],PRIMEM[\""Greenwich\"",0],UNIT[\""degree\"",0.0174532925199433]],PROJECTION[\""Azimuthal_Equidistant\""],PARAMETER[\""latitude_of_center\"",90],PARAMETER[\""longitude_of_center\"",0],PARAMETER[\""false_easting\"",0],PARAMETER[\""false_northing\"",0]]""; } if (ZNA == 18) { osSRS = ""PROJCS[\""ARC_System_Zone_18\"",GEOGCS[\""GCS_Sphere\"",DATUM[\""D_Sphere\"",SPHEROID[\""Sphere\"",6378137.0,0.0]],PRIMEM[\""Greenwich\"",0],UNIT[\""degree\"",0.0174532925199433]],PROJECTION[\""Azimuthal_Equidistant\""],PARAMETER[\""latitude_of_center\"",-90],PARAMETER[\""longitude_of_center\"",0],PARAMETER[\""false_easting\"",0],PARAMETER[\""false_northing\"",0]]""; } }}} The attached zip file contains 3 ASRP polar test datasets. The cell size and origin of the test images are given in the following table. ||=Dataset=||=Cell Size X=||=Cell Size Y=||=Origin X=||=Origin Y=|| ||TEST0101||100.0914539||100.0914539||-307480.946||-179363.885|| ||TEST0201||100.0914539||100.0914539||115305.354||153740.473|| ||TEST0501||100.0914539||100.0914539||-307480.946||153740.473|| ",defect,closed,normal,2.1.1,GDAL_Raster,1.8.0,normal,fixed,ASRP Polar Zones Azimuthal Equidistant Projection,