PROJECT NAME ExoSabrina_5 HIRISE SOURCE IMAGES ESP_036517_1920 ESP_036583_1920 TECHNICAL CONTACT INFORMATION NAME JOEL DAVIS INSTITUTION UNIVERSITY COLLEGE LONDON Products are tied to MOLA elevations. Elevation range for this project: VALID_MINIMUM = -2767.97 m VALID_MAXIMUM = -2659.45 m SOCET SET NGATE was used to extract terrain. Post spacing in DTM is 1 m. NOTE: Total RMS ==> 0.40643 px The OFFSET and SCALING_FACTOR values in the orthoimage labels to convert DN values to I/F are not available for this project. NAMING CONVENTION: DTM PRODUCT_ID = aabcd_xxxxxx_xxxx_yyyyyy_yyyy_Vnn where aa = DT, indicating it's a DTM product b = type of data E = areoid elevation R = radii F = Figure of Merit (FOM) map (Extra product, see below) c = projection (others are possible but these are the important ones) E = Equirectangular P = Polar Stereographic d = grid spacing A = 0.25 m B = 0.5 m C = 1.0 m D = 2.0 m etc. xxxxxx_xxxx = orbit number and target code from SOURCE_PRODUCT_ID[1] yyyyyy_yyyy = orbit number and target code from SOURCE_PRODUCT_ID[2] V = letter indicating producing institution U = USGS A = University of Arizona C = Caltech P = Planetary Science Institute O = Open University L = University College London nn = 2 digit version number ORTHOIMAGE PRODUCT_ID = XSP_xxxxxx_xxxx_CCC_S_NN_ORTHO where XSP_xxxxxx_xxxx = HiRISE source observation ID (mission phase_orbit number_target code) CCC = color content RED = visible RED, 1 band image IRB = 3 band enhanced color (IR, RED, BG) S = grid spacing (comparable to the DTM naming convention above) A = 0.25 m B = 0.5 m C = 1.0 m D = 2.0 m etc. NN = a sequence number to distinguish between orthorectified images from the same HiRISE observation that may be created from different DTMs. ORTHO indicates that the image has been orthorectified Figure of Merit (FOM) Map The FOM Map (DTF...JP2) shows stereo correlation quality for each pixel (elevation post) in the DTM. The quality categories are identifed in the legend file FOM_MAP_LEGEND.JPG. Figure of merit (FOM) values are automatically collected by SOCET SET 5.x as part of the stereo correlation for the output DTM. These values are then simplified into a more generically defined value based on the Lunar Mapping and Modeling Project (LMMP) Confidence Map categories. SOCET Set (FOM) values FOM Map Color Category Description ------------ ------------- ------------------- 1 Black No data, outside boundary 2 Dark Blue Shadow (if designated as such) 3,5-20,28,31-39 Orange Suspicious (edge, corner, did not correlate, other bad value, derived from seed DTM) 4,30 Red Interpolated/extrapolated (e.g. from neighbor pixels) 21 Pink Saturated (in source images) 22-27,29 Cyan Manually edited/interpolated or smoothed 40-59 Yellow Low end of good correlation range 60-99 Sea Green Good correlation The FOM map shows the color-coded categories draped over a shaded relief map. KNOWN ARTIFACTS These are known artifacts present in some, but not all, HiRISE DTMs. They may not be present in this DTM! Look at the terrain shaded relief to detect these before using the DTM! - Boxes Some DTMs have square areas that are usually about .5-1 m different in elevation from the surrounding areas. These are artifacts of the processing algorithms used in Socet Set ((c) BAE Systems). There may be goups of these boxes. They are almost impossible to edit, so the user should look for such artifacts in a terrain shaded relief map before using the DTM for analysis. - CCD seams A HiRISE image is made up of 10 individual images, stitched together along their long edges. In a DTM, these seams can be visible as long lines. These seams are difficult to remove. - Faceted areas Areas that were very bland (low contrast) or deeply shadowed with low contrast and low signal may have a "faceted" look to them. Terrain in these areas is not trustworthy.