PROJECT NAME Nili_Patera_Dunes HIRISE SOURCE IMAGES ESP_017762_1890 ESP_018039_1890 TECHNICAL CONTACT INFORMATION NAME UNIV OF ARIZONA INSTITUTION UNIVERSITY OF ARIZONA Products are tied to MOLA elevations. Elevation range for this project: VALID_MINIMUM = 55.11 m VALID_MAXIMUM = 275.45 m SOCET SET NGATE was used to extract terrain. Post spacing in DTM is 1 m. Notes: Some areas of this DTM were edited. Edited areas are highlighted in red in the EXTRAS file ending in .em.jpg. This image shows the areas where the terrain model was edited by hand. This might have involved correcting obvious blunders, or minimizing some of the artifacts noted below. The user should note these areas and understand that the terrain in edited areas has either been measured by hand or with an area editing tool. We only edit areas where we feel improvements can be made to the results of the automatically generated terrain. Note that we often edit only regions of special interest to the original suggester of the DTM; other bad areas may remain unedited. 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 out, 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 from the whole - 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.