John R. Weirich 06 Sep 2022 Product Description for "Regional Topography and Photometric Cube Data for Lunar Locations" This package contains topography and photometric data generated by the Gaskell Stereophotoclinometry (SPC) software suite. A list of locations follows. Nearest Feature Name Center Lat/East Lon Size (km) Dorsa Aldrovandi 25.84/29.07 10 by 10 Mare Ingenii (Loc 1) -35.84/161.81 9 by 9 Mare Ingenii (Loc 2) -33.59/163.35 9 by 9 Karpinskiy Crater 73.77/167.61 5 by 20 Mare Moscoviense 26.51/144.34 7 by 7 Reiner Gamma Swirl 7.02/300.80 7 by 7 Tsiolkovskiy Crater -19.42/128.57 10 by 10 Topography Data We generated regional Digital Terrain Models (DTM) using LROC NAC images from both the right and left cameras. The topography data is provided in both cubes readable by the USGS ISIS program, and as a geoTiff which can be read by programs such as ArcGIS. Estimates of the topographic error of SPC DTMs come from testing for the OSIRIS-REx mission. Weirich et al (2022) used a synthetic, but realistic, digital asteroid with known heights to produce a simulated mission image suite. With only these images, and no access to the synthetic asteroid, we generated an SPC global DTM. This SPC DTM was then compared to the original synthetic DTM to characterize the actual errors. Weirich et al (2022) showed that a sufficient, but not ideal, image set produced DTMs that were typically accurate to one image pixel. The worst vertex in the test DTM was accurate to about three image pixels. We use the above values as an estimate for the DTM errors in this package. The image set of this package is comparable to the sufficient, but not ideal, image set of the OSIRIS-REx tests. Unlike the OSIRIS-REx testing, we did not build the DTMs at the image resolution. So instead of the typical vertex being accurate to one image pixel, it is accurate to one DTM vertex. Likewise, the worst DTM vertex is likely to be accurate to three DTM vertices. Formats Cubes: The cubes are not projected but are near north up. Orientation vectors are given in the PDS label under local_georeference_information. The cubes are given in "SPC space" so that resampling of the SPC data does not occur. The horizontal spacing between the pixels is the vertex spacing of the DTM (see individual locations below for values). Three cubes fully define the topography. These are topography, latitude, and longitude cubes. The topography cube is the elevation values in meters from the lunar datum of 1737.4 km, the latitude cube is the Latitude value of that vertex in degrees, and the longitude cube is the East Longitude value of that vertex in degrees. Some locations consist of multiple overlapping DTMs. These are noted in the "Location" section. GeoTiff: The geoTiffs are projected and have square pixels. As such, they represent resampled values from the topography generated by SPC. The SPC data was converted using the Generic Mapping Tool (GMT) program nearneighbor. The program parameters were a search radius of 0.001 degrees, 16 sectors, and a minimum of 8 sectors. If there were not enough valid vertices to meet these parameters, then a NoData value of -3.40282306073709653e+38 is written. A single geoTiff records the elevation in meters from the lunar datum of 1737.4 km, as well as the latitude and longitude of each vertex. If the region consists of multiple overlapping DTMs, they are all combined into one geoTiff. Photometric Data We generated photometric data (in cube format) that is aligned to and has the same horizontal spacing as the topographic cube data. For each LROC image, four cubes were generated; I/F (reflectance), Local Phase Angle, Local Emission Angle, and Local Incidence Angle. Part of the SPC process is to align each image to the topography by adjusting the position and pointing of the spacecraft. The alignment is typically accurate to the size of 1 vertex or better, though rarely for some images in localized areas the misalignment may be as large as 3 or 4 vertices. All angles were determined by the Sun and spacecraft position relative to the height of each DTM vertex. All cubes of a particular location are in the same physical space. In other words, px,ln 100,100 of the topography cube maps to px,ln 100,100 in all the other cubes giving I/F, local phase, incidence, and emission angles for all images. Note that while some cubes have values for all pixels, only pixels that correspond to non-zero values in the reflectance cube (i.e. I/F or "ioverf") are valid. Unit Definition Data Mare Ingenii has unit definition data we used in the analysis of the data (Domingue et al., 2022). This data has three forms, 1) a mosaic of low incidence angle images (i.e. albedo) with craters masked out, 2) a mapping of the Lunar swirls with craters masked out, and 3) a topography map with craters masked out. All unit definition data is given in geoTiff format. Note that product 2) for ings358416181 has mapping of on-swirl=1, off-swirl1=2, off-swirl2=3, no data=4. Off-swirl1 and off-swirl2 were chosen to have the same width to provide data at two distances from the swirl. Product 2) for ings335916335 has on-swirl=1, off-swirl=2, no data=3. File Naming Schema All filenames in this package begin with a identifier. This identifier has both region and central lat/lon DTM information. The first three characters will be of an abbreviated version of the region, the next five for the latitude, and the next five for longitude. The latitude is represented by an "n" for North and an "s" for South, followed by the numeric value of the latitude accurate to two decimal places (the decimal point is omitted). The longitude is represented by the numeric value in East Longitude accurate to two decimal places (again omitting the decimal point). Location examples: Dorsa Aldrovandi 25.84 Lat, 029.07 E Lon becomes aldn258402907 Mare Ingenii -34.84 Lat, 161.81 E Lon becomes ings358416181 For photometric data, the next identifier is the last five digits of the LRO image name, plus an "l" for left or "r" for right. So M116126693R becomes 26693r. The next identifier is , which will be "topo" for topography, "lat" for latitude, "lon" for longitude, "ioverf" for I/F, "a" for phase, "e" for emission, and "i" for incidence. The last identifier is one or two characters to make the cube and geoTiff xml labels unique. "c" will be used for cubes, while "g" will be for geoTiff. For some locations there are two DTMs that have the same central lat/lon but different horizontal spacing. In these instances "c1" is the larger (worse) horizontal spacing, while "c2" is the smaller (better) horizontal spacing. In these instances, the photometric cubes will also display a "c1" because they are associated with the "c1" topography, and the geoTiffs will display a "g2" because they are associated with the "c2" topography. Thus, all topography, latitude, and longitude cubes will have the filename structure: __c[1,2].cub Note: Some locations will have "c1" and "c2", while others will just have "c". All topography geoTiffs will have the filename structure: _topo_g[2].tif Note: Some locations will have "g2", while others will just have "g". This is because, when there are two DTMs with the same central lat/lon, we only provide the topography of the better horizontal spacing in geoTiff format. All photometric cubes will have the filename structure: ___c[1].cub Note: Some locations will have "c1", while others will just have "c". This is because, when there are two DTMs with the same central lat/lon, all photometric cubes will be associated with the topography of the worse horizontal spacing. Locations This package contains DTMs for six regions. ---------------------------------- Dorsa Aldrovandi: spacing of 6.4 m/vertex This location was constructed to analyze wrinkle ridges. 29 Images used to generate the topography M116126693L M116126693R M142075391L M142075391R M155044325L M155044325R M1101016482L M1101016482R M1113979380L M1113979380R M1116337645R M1142255329R M1149317892R M1179930995L M1179930995R M1184640003L M1184640003R M1197569085L M1197569085R M1197583152L M1197583152R M1218759202L M1225820611L M1225820611R M1299916113L M1310473854L M1310473854R M1328118625R M1353958065R 17 Images in cubes M116126693R M155044325L M155044325R M1101016482L M1101016482R M1142255329R M1149317892R M1197569085L M1197569085R M1197583152L M1197583152R M1218759202L M1225820611L M1225820611R M1310473854L M1310473854R M1328118625R ---------------------------------- Mare Ingenii: The southern location was originally constructed to follow up on a water signature found in M3 data, possibly due to cooler temperatures in the bright on-swirl areas. This data was later used to investigate swirl formation mechanisms, and a second northern location was generated to follow up on possible height differences between on- and off-swirl regions. Both the northern and southern locations have smaller areas of hi-resolution topography strips that were constructed at the image resolution. Further details can be found in Domingue et al. (2022). Location at -35.84 Lat 161.81 E Lon has spacing of 5 m/vertex and 2.5 m/vertex Check "Known Issues" for details on edge effects 17 Images used to generate topography and cubes M115252292L M115252292R M164791607R M180107476L M180107476R M184818082R M184825229R M1097795227L M1102510544L M1102510544R M1109583890L M1109583890R M1124884018R M1124891128L M1124891128R M1135504503L M1137857807R Location at -35.84 Lat 161.90 E Lon has spacing of 0.80 m/vertex Ten overlapping DTMs define this location. A subset of the images used for location -35.84 Lat 161.81 E Lon were used for this hi-resolution strip. Location at -33.59 Lat 163.35 E Lon has spacing of 2.6 m/vertex 39 images used to generate topography and cubes M105802305L M105802305R M112883561L M112883561R M189528774L M1097788036R M1120165013L M1120165013R M1128423456L M1128423456R M1133137598R M1137843545L M1137843545R M1137850655L M1137850655R M1150783018L M1163750779L M1163750779R M1163757893R M1168464712R M1183744016L M1183744016R M1183758218L M1220258422L M1220258422R M1220265455L M1220265455R M1220272488L M1220272488R M1222607556L M1224963678L M1235522307L M1235522307R M1235529339L M1235529339R M1242583258L M1242583258R M1270799282R M1281411275R Location at -33.60 Lat 163.32 E Lon has spacing of 0.70 m/vertex Ten overlapping DTMs define this location. A subset of the images used for location -33.59 Lat 163.35 E Lon were used for this hi-resolution strip. ---------------------------------- Karpinskiy Crater: Four overlapping DTMs define this location, spacing is 5 m/vertex This location was generated to follow up on a water signature found in M3 data, and the thermal properties can be more accurately modeled with accurate heights and slopes. 23 Images used to generate topography and cubes Check "Known Issues" for details on edge effects M110511721L M115229879L M118744525L M130545991R M171806668R M171813453L M180088277L M180095426R M184806002L M184813150R M1095363608L M1095377899R M1102444024R M1113099667L M1115457794L M1122539559L M1153162919R M1161314495L M1161314495R M1176712701L M1179071974R M1179079193L M1196625634L ---------------------------------- Mare Moscoviense: spacing of 2.6 m/vertex This location was constructed to investigate lunar swirl formation mechanisms. 25 images used to generate topography and cubes M105930197L M105930197R M108291109L M108291109R M118906460R M192017555L M192017555R M1097901138L M1102616445L M1102616445R M1107331435L M1110875629R M1117943030L M1120301140L M1120301140R M1125020338R M1128536017L M1128536017R M1135602780R M1148570508R M1155632037L M1166217682R M1170929570L M1174473153L M1205077454L ---------------------------------- Reiner Gamma Swirl: spacing of 5 m/vertex and 2.6 m/vertex This location was constructed to investigate lunar swirl formation mechanisms. 29 images used to generate topography and cubes M102536848L M102544013L M102551166L M109623648L M109623648R M152250376L M190987807R M1101595388L M1101602532R M1103952583R M1108668263L M1112203387L M1112203387R M1129873381R M1132227006L M1132234115R M1134586730R M1136939671R M1136946783L M1139300406L M1145170190L M1145191527L M1145198641L M1145205753L M1149901166L M1149901166R M1152264615L M1165201476L M1178153942R ---------------------------------- Tsiolkovskiy Crater: spacing is 5 m/vertex Topography and photometric cube products are discussed further in Domingue et al. (2018). This location was constructed because it did not have a water signature in M3 data, and stands as a contrast to Mare Ingenii and Karpinsky crater's thermal profiles. 10 Images in cubes Check "Known Issues" for details on edge effects. M167370048R M110751047R M167363261L N103668324L N123730396L N103675484L M143785506L M143785506R M192116691L M143778723R References: Deborah Domingue, Eric Palmer, Robert Gaskell, and Matt Staid (2018) Characterization of Lunar Surface within Tsiolkovsky Crater: Photometric Properties, Icarus, doi:10.1016/j.icarus.2018.02.034 Deborah Domingue, John Weirich, Frank Chuang, Amanda Sickafoose, and Eric Palmer (2022). Topographic correlations within lunar swirls in Mare Ingenii. Geophysical Research Letters, 49, https://doi.org/10.1029/2021GL095285 John Weirich, Eric Palmer, Michael Daly, Olivier Barnouin, Kenneth Getzandanner, John Kidd Jr., Coralie Adam, Robert Gaskell, and Dante Lauretta (2022) Quality Assessment of Stereophotoclinometry as a Shape Modeling Method Using a Synthetic Asteroid. Planetary Science Journal, 3, https://doi.org/10.3847/PSJ/ac46d2