Calculated Location Standard Deviation (m) Total Spread (m)

Lat Lon Radius (m) Lat Lon Lat Lon ImagesA11 LMa 0.67415 23.47315 1,735,474b 0.5 1.2 2.6 7.3 47A11 PSEa 0.67321 23.47315 1,735,472b 0.7 1.2 4.2 6.9 46A12 LM -3.0128 336.5781 1,735,978b 6.3 3.5 27.4 15.7 43A12 ALSEP -3.0098 336.5751 1,735,978b 5.1 3.3 21.1 17.3 35A14 LMa -3.64589 342.52805 1,736,338b 0.6 1.1 3.2 4.2 23A14 ALSEPa -3.64419 342.52231 1,736,336b 0.6 0.8 2.2 3.9 23A15 LMa 26.13237 3.63332 1,735,469b 0.5 1.7 1.8 7.2 23A15 ALSEPa 26.13406 3.62992 1,735,476b 0.4 1.3 1.6 5.1 24A15 LRV 26.13174 3.63805 1,735,472b 0.6 1.2 2.3 5.6 22A16 LM -8.9734 15.5010 1,737,408b 6.4 2.8 27.6 13.3 24A16 ALSEP -8.9758 15.4985 1,737,412b 6.1 2.9 26.9 12.9 22A16 LRV -8.9729 15.5037 1,737,410b 6.6 3.2 26.9 14.9 22A17 LM 20.1911 30.7723 1,734,774b 6.8 3.0 24.3 12.5 23A17 ALSEP 20.1923 30.7655 1,734,778b 6.6 3.6 26.0 15.2 20A17 LRV 20.1896 30.7769 1,734,772b 6.8 3.1 26.3 14.0 23

Calculated Location Standard Deviation (m) Total Spread (m)

Lat Lon Radius (m) Lat Lon Lat Lon Images

Surveyor 1 -2.4745 316.6602 1,735,511d 6.9 4.8 17.5 13.6 7

Surveyor 3 -3.0162 336.5820 1,735,967b 7.2 4.1 40.3 23.4 40

Surveyor 5 1.4550 23.1944 1,735,348d 12.6 4.2 27.8 10.6 5

Surveyor 6 0.4743 358.5725 1,736,643d 5.5 2.6 13.8 6.9 5

Surveyor 7 -40.9811 348.4873 1,737,481d 3.3 7.9 11.4 30.6 11

Luna 16 -0.5137 56.3638 1,734,948b 6.1 2.1 19.9 8.0 16

Luna 17a 38.23763 324.99847 1,734,929b 1.3 1.3 7.0 5.8 29

Lunokhod 1e 38.3151 324.9919 1,734,929c 9.8 5.9 46.2 23.7 29

Luna 20 3.7863 56.6242 1,735,620b 8.1 2.7 27.2 9.2 16

Luna 21 25.9993 30.4077 1,734,720b 13.2 7.9 41.1 21.4 8

Lunokhod 2e 25.8323 30.9221 1,734,639c 12.0 5.2 48.9 17.0 14

Luna 23 12.6669 62.1511 1,733,732b 8.5 2.5 29.5 10.8 26

Luna 24 12.7145 62.2129 1,733,730b 8.8 2.7 30.2 13.3 24

Chang'e 3 44.1213 340.4885 1,734,773b 10.9 11.6 26.5 26.2 5

Yutu Rover 44.1210 340.4880 1,734,773b 10.0 13.1 26.2 30.1 5

Calculated Location Standard Deviation (m) Total Spread (m)

Lat Lon Radius (m) Lat Lon Lat Lon ImagesRanger 6 9.3866 21.4806 1,735,409b 5.7 3.0 16.1 10.6 8Ranger 7 -10.6340 339.3229 1,735,609d 6.3 2.9 21.7 7.9 8Ranger 8 2.6377 24.7881 1,735,235d 7.9 4.9 25.1 15.2 8Ranger 9 -12.8281 357.6116 1,735,878b 5.2 2.9 15.0 9.9 8A13 SIVB -2.5550 332.1126 1,736,244b 10.0 4.4 28.2 14.5 11A14 SIVB -8.1810 333.9695 1,735,615d 7.5 5.2 26.5 18.0 10A15 SIVB -1.2896 348.1755 1,736,301b 4.4 4.6 15.1 15.3 20A17 SIVB -4.1681 347.6693 1,736,231b 10.1 1.9 35.4 6.1 12GRAIL-A 75.6083 333.4043 1,738,169d 5.1 3.2 15.1 9.0 10GRAIL-B 75.6504 333.1643 1,738,451d 4.6 3.6 14.3 11.5 9

Introduction

Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images, with resolutions from 0.25-1.5 m/pixel, allow the identifcation of historical and present-day landers and spacecraft impact sites. Repeat observations, along with recent improvements to the spacecraft position model [1] and the camera pointing model [2], allow the precise determination of coordinates for those sites. Accurate knowledge of the coordinates of spacecraft and spacecraft impact craters is critical for placing scientifc and engineering observations into their proper geologic and geophysical context as well as completing the historic record of past trips to the Moon.

To date, we have identifed almost all of the robotic soft landers that landed successfully (Surveyor, Luna, Chang’e 3), including the rovers associated with three of them (Lunokhod 1 and 2, and Chang’e 3 Yutu). We have not yet located the frst two successful lunar landers (Luna 9 and Luna 13, launched by the Soviet Union), which are very small relative to the NAC pixel scale and have poorly-constrained landing coordinates. We have also identifed both GRAIL impact sites, four Ranger and four Apollo Saturn-IVB impact sites. The locations of crewed Apollo Lunar Module (LM) descent stages, Lunar Roving Vehicles (LRV), and science instruments were also identifed in NAC images.

Locations of Anthropogenic Sites on the MoonR. V. Wagner1, M. S. Robinson1, E. J. Speyerer1, and J. B. Plescia2

1Lunar Reconnaissance Orbiter Camera, School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-3603; rvwagner@asu.edu2The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723

References

[1] Mazarico, E. et al. (2011), J Geodesy, doi:10.1007/s00190-011-0509-4.[2] Speyerer, E. J. et al. (2014), Space Sci. Rev. (in review)[3] Roncoli, R. (2005), JPL D-32296.[4] Davies, M. E. and Colvin, T. R. (2000), JGR, 105, 20,277-20,280.[5] Williams, J. G. et al. (2008), JPL IOM 335-JW,DB,WF-20080314-001, March 14, 2008.

[]Wagner, R. V. et al. (2012), Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XXXIX-B4, 517-521, doi:10.5194/isprsarchives-XXXIX-B4-517-2012.

Map of the locations of all of the anthropogenic features located in this work. Orange indicates impactors, blue indicates unmanned landers, and green indicates Apollo landing sites.

Historical Background

Prior identifcations of anthropogenic targets were made from Apollo-era photography, radio tracking, and laser ranging. Historic coordinates for many anthropogenic targets were summarized in [3] and were used as starting points for locating the landing and impact sites in NAC images.

Davies and Colvin [4] refned estimates of Apollo equipment based on laser ranging at three of the six landing sites, radio tracking of ALSEP radio signals (interferometry) that gave the distances between the ALSEP central stations, and photogrammetry of surface photos to derive the relative and absolute positions of the LMs and other equipment. Our coordinates are consistent with those of Davies and Colvin, while refning the accuracy and including non-Apollo sites.

Abstract #2259

More TablesScan this QR code to go

to an LROC Featured Image post with a table

of object coordinates for each image.

Methods and Accuracy

To get the location of each object, we recorded its line and sample in each image it appears in, and then used USGS ISIS routines to extract latitude and longitude for each point. The true position is calculated to be the average of the positions from individual images, excluding any extreme outliers. This process used Spacecraft Position Kernels improved by LOLA cross-over analysis and the GRAIL gravity model, with an uncertainty of ±10 meters [1], and a temperature-corrected camera pointing model [2].

At sites with a retrorefector in the same image as other objects (Apollo 11, 14, and 15; Luna 17), we can improve the accuracy signifcantly. Since the retrorefector positions are known to meter-level accuracy from Earth-based laser ranging [5], we used ISIS routines to fx the retrorefector pixel at its known coordinates before calculating the coordinates for other objects. This reduced variance in the calculated hardware locations by a factor of 5.

For the Chang’e 3 lander, cross-over corrected kernels are not currently available for images that contain the lander and rover, so we used post-landing images to identify the landing position in pre-landing images, and derived the coordinates from the “prior” images.

Impacts

Ranger Program: The United States' Ranger spacecraft (1961-1965) were designed to image portions of the Moon at high resolution, which they accomplished by entering a decayingorbit, and imaging until they hit the surface. This resultedin spectacular images, as well as spectacular craters.

Apollo SIV-Bs: On each of the United States' Apollo missions (1969-1972), the Saturn IV-B booster was used to leave Earth orbit. On Apollos 13 through 17, the SIV-B was later maneuvered to impact the Moon, providing a strong signal for the Apollo seismic network.

GRAIL: The GRAIL mission (2011-2012) consisted of two orbiters, Ebb and Flow, which mapped the Moon's gravity feld in unprecedented detail. After a successful mission, they were commanded to crash into the surface. LROC was able to acquire images of the impact site both before and after the impact, allowing us to locate the 5 meter craters.

Apollo Landings

The United States' Apollo landings (1969-1972) were the frst, and so far only, crewed missions to the Moon. At the six landing sites, we recorded the positions of the following features:

LM: The descent stage of the Landing Module.ALSEP: The central station of the Apollo Lunar Surface Experiment Package, which handled communication and power distribution for the experiments the astronauts left on the surface.LRRR: Laser Ranging RetroRefector.PSE: Passive Seismic Experiment. Apollo 11 only left an LRRR and seismometer on the surface, so the seismometer package housed its own power and communication systems.LRV: The fnal parking spots of the Lunar Roving Vehicles, on Apollos 15, 16, and 17.

Robotic Landers

Surveyor Program: From 1966 to 1968, the United States launched seven Surveyor robotic landers as a precursor to the Apollo manned landings. Five of them landed success-fully, and one, Surveyor 3, was later visited by Apollo astronauts.

Luna Program: The Soviet Union launched a number of lunar missions from 1958 to 1976, eight of which were landers that made it to the surface in one piece (although the Luna 23

sample return mission fell over on landing). Two of them Luna 17 and 21, carried Lunokhod rovers, both of which traversed several kilometers over a few months.

Chang'e 3: In December 2013, China launched the frst lunar lander in 37 years, which successfully landed and deployed a small rover, named Yutu. See poster #304 (abstract #1859) for more about LROC imaging of Chang’e 3.

Left: Spread of projected locations for each measured object at the Apollo 12 landing site. Each colored dot marks the location from one image; the yellow dots mark the average locations.Above: Spread of projected locations for the Luna 17 lander, after calibrating with the retrorefector mounted on the Lunokhod 1 rover 2.3 km north. Scale matches in both fgures.

More ImagesScan this QR code for many more images of these landing and impact sites.

Table footnotes: aCoordinates adjusted for retrorefector locations. bElevation from NAC DTM. cElevation from laser ranging. dElevation from GLD100. eLunokhod 1 and 2 calculated values differ from retrorefector coordinates by < 4 m.