PROJECT NAME Apollo 11 Landing Site LROC NAC SOURCE IMAGES M150361817 L/R M150368601 L/R TECHNICAL CONTACT INFORMATION NAME ARIZONA STATE UNIVERSITY INSTITUTION ARIZONA STATE UNIVERSITY DATE CREATED September 17, 2012 - Products are tied to LOLA elevations with RMS error of 1.81 m to 7.0 different LOLA orbit tracks. The RMS error is the root-mean-square of the elevation difference between the LOLA points and the DTM. This value is a combination of error from the LOLA points and the DTM, and may give a measure of the horizontal and vertical accuracy of the DTM. - The reported precision error from SOCET SET is 0.77 m. - SOCET SET NGATE v5.5 was used to extract terrain. - Post spacing in DTM is 2.0 m. - DTM start time: 2011-01-22 18:55:49 and DTM stop time: 2011-01-22 20:49:11. - DTM extents: Min. Lat.: 0.31464201 Min. Lon.: 23.37231647 Max. Lat.: 1.23650584 Max. Lon.: 23.51150435 ORTHOPHOTO NOTE: These orthophotos do not include scale and offset information. KEY FEATURES - Anthropogenic - Mare REFERENCE For more information on the methodology and error analysis of the DTMs, see: M.R. Henriksen, M.R. Manheim, K.N. Burns, P. Seymour, E.J. Speyerer, A. Deran, A.K. Boyd, E. Howington-Kraus, M.R. Rosiek, B.A. Archinal, and M.S. Robinson. Extracting accurate and precise topography from LROC narrow angle camera stereo observations. Icarus (2016). http://dx.doi.org/10.1016/j.icarus.2016.05.012 RDR SIS: http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/DOCUMENT/RDRSIS.PDF LINKS TO BROWSE IMAGES http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_CLRDISC_LEGEND.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_CLRDISC.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_CLRGRAD_LEGEND.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_CLRGRAD.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_CONF.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_E008N0234.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_M150361817_2M.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_M150361817_50CM.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_M150368601_2M.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_M150368601_50CM.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_SHADE.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_SLOPE_LEGEND.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11_SLOPE.BROWSE.PNG http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_DTM/APOLLO11/NAC_DTM_APOLLO11.BROWSE.PNG GENERAL NOTES: KNOWN ARTIFACTS These are known artifacts present in some, but not all, LROC NAC DTMs. These artifacts may not be present in this DTM! Look at the terrain shaded relief and the confidence map to detect these before using the DTM! - Boxes Some DTMs have rectangular areas that are usually about 0.5-1.0 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 groups 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. - NACL and NACR seams There are two NAC cameras (NACL & NACR) on board LRO. Stereo images are collected by acquiring images on two different orbits so the total parallax angle is greater than 12 degrees. The overlap between the four images (two pairs of NACL and NACR) provides three or four stereo models from which to collect elevation data. These stereo models are stitched together into one DTM. In some DTMs, the seams between the stereo models may be visible as long lines, usually up to 1 m difference. These seams are difficult to remove from the whole DTM. - 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. This is due to the processing algorithm not able to correlate the images and must interpolate to fill in the pixel. The terrain data in these areas are not trustworthy. Use the confidence map to look for "suspicious" data points. - Noise DTMs have varying level of noise from low signal images, low incidence angle, and jitter. The amount of noise may be detected using the slope map or the confidence map. PDS PRODUCT NAMING CONVENTION The PRODUCT_ID naming convention for LROC NAC DTMs is: NAC_DTM_xxxxxxxxxxx_AyyyBzzzz.IMG where - NAC_DTM = indicating it's a NAC DTM product - xxxxxxxxxx = words specifying the sitename (up to 11 characters) - A = projection type (E for equirectangular, P for polar stereographic) - yyy = center latitude to the nearest 10th of a degree - B = N for northern hemisphere, S for southern hemisphere - zzzz = center longitude to the nearest tenth of a degree. The longitude domain for all NAC DTMs is 360 positive east. Example: NAC_DTM_LINNECRATER_E280N0120.IMG is a NAC DTM of Linne Crater located at latitude=28.0N, longitude=12.0E in equirectangular projection. RELATED DTM PRODUCTS For each NAC DTM, we also produce several related products. The naming convention for these products is: _ where refers to NAC_DTM_xxxxxxxxxxx and refers to the type of product (see details below). - Ortho-rectified images We provide 4 ortho-rectified images, a mosaic of the NACL_1 and NACR_1 and a mosaic of NACL_2 and NACR_2 in two resolutions (DTM resolution and image resolution). The part of the filename is the name of the NAC image and the resolution. - Colorshades and colorshade legends The colorshade images are color-coded topography draped over the shaded relief. The colorshade legend explains what the color means. There are two versions: a discrete colorshade that bins the data to emphasize topography, and a gradient colorshade that is a continuous color map. The for the discrete colorshade image is CLRDISC and the discrete colorshade legend is CLRDISC_LEGEND. The for the gradient colorshade image is CLRGRAD and the gradient colorshade legend is CLRGRAD_LEGEND. - Color slope map and slope map legend The color slope map is the color-coded slope (in discrete increments) draped over the shaded relief. The slope map legend explains what the color means. The for the color slope map is SLOPE and the slope map legend is SLOPE_LEGEND. - Shaded Relief The shaded relief image is generated with the sun azimuth of 315 degrees (northwest) and sun altitude of 45 degrees. The for the shaded relief image is SHADE - DTM in Geotiff format We also provide the DTM in GeoTIFF format to allow users more flexibility in using the DTM. There are no for this file, and the filename is simply .tif - Readme The readme file contains description of the DTM, precision and accuracy information, description of known artifacts, naming convention, related products, and confidence table lookup. The for the readme file is README. CONFIDENCE MAP TABLE LOOKUP Value Description 0 NoDATA, outside boundary (e.g. out of stereo pair overlap) 1 Shadowed 2 Saturated 3 Suspicious (edge, corner, did not correlate, etc.) 4 Interpolated / Extrapolated (e.g. from neighbor pixels) 10-14 Value range of successful correlations 15 Manually edited