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International Archives of the Photogrammetry, Remote Sensin 
g and Spatial Information Sciences, Volume XXXIX-B4, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
REVISED COORDINATES FOR APOLLO HARDWARE 
R. V. Wagner *, E. J. Speyerer, K. N. Burns, J. Danton, M.S. Robinson 
Lunar Reconnaissance Orbiter Camera, School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA 
, 
85287-3603 — rwagner@ser.asu.edu 
KEY WORDS: Georeferencing, Geodesy, Identification, Reference Data, Accuracy 
ABSTRACT: 
The Narrow Angle Camera (NAC) on the Lunar Reconnaissance Orbiter provides direct imaging, at pixel scales of 0.5 to 1.0 meter, 
of anthropogenic equipment left on the Moon. We identified the descent stages of the lunar modules, central stations of the Apollo 
Lunar Surface Experiments Package, Laser Ranging Retroreflectors (LRRRs), and Lunar Roving Vehicles in each NAC image of the 
Apollo landing sites. The pixel coordinates of those objects were then converted to latitude and longitude coordinates using SPICE 
routines in the U.S. Geological Survey Integrated System for Imagers and Spectrometers. For images that contained an LRRR, 
pointing information was updated to match the well known LRRR coordinates. Final coordinates for each object are reported as 
averages from multiple images. NAC observations allow refinement of the locations of these objects and result in a more accurate 
geodetic referencing at these historic sites. Additionally, the anthropogenic coordinate analysis enables realistic error estimates for 
NAC derived coordinates for features anywhere on the Moon. 
1. INTRODUCTION 
The positions of the three Apollo Laser Ranging Retroreflectors 
(LRRRs), along with the retroreflectors on the two Soviet 
Lunokhod rovers, are known to centimeter-level accuracy 
(Williams, 1996, 2008). The relative positions of the Apollo 
Lunar Surface Experiment Package (ALSEP) central stations at 
all six Apollo sites are known to 30 m accuracy from very long 
baseline interferometry (VLBI) experiments (King, 1976). 
Previous work by Davies and Colvin in 2000 combined these 
two datasets, using ground-level image photogrammetry and the 
historic United States Geological Survey (USGS) landing site 
maps to determine the relative positions of the Apollo LRRRs, 
ALSEP central stations, lunar module descent stages (LM), 
along with almost fifty notable craters. Analysis of Lunar 
Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera 
(NAC) images provides the means to improve on this earlier 
work through identification of a wider set of objects on the 
surface, such as the Lunar Roving Vehicles, or LRVs (Figure 
1). Furthermore, due to  well-constrained position and 
orientation information for the Lunar Reconnaissance Orbiter 
(LRO), NAC images are used to directly measure feature 
locations to high accuracy (+22 m). With the additional 
accuracy provided by an LRRR within an image, we can 
measure the locations of human artifacts to an even higher level 
of confidence (+2m). 
2. METHODS 
2.1 Image Selection 
Each object of interest was identified in multiple NAC images; 
identifications were confirmed by comparisons to ground-level 
Apollo handheld photographs. For objects that extend over 
more than one NAC pixel, the center pixel was used for 
coordinate computation. 
NAC images were analyzed if they fell within the time period 
where improved orbital positioning information is available 
from radiometric and Lunar Orbiter Laser Altimeter (LOLA) 
  
* Corresponding author. 
  
Figure 1: The objects identified at each site. Clockwise from 
top left: LM descent stage, LRV, LRRR, ALSEP central 
station. 
cross-over analysis, which improves the spacecraft position 
uncertainty to «20 m (Mazarico, 2012). The improved 
spacecraft position kernels are currently available from the start 
of the mission through 11 December 2011. Additionally, images 
from the LRO commissioning phase (3 July to 15 September 
2009) were not included for two reasons: First, the spacecraft 
ephemeris is less accurate during this time period. Second, the 
spacecraft was in a higher orbit during the commissioning 
phase, with image resolutions ranging from 1-1.5 m at the 
Apollo sites, making it difficult to confidently identify pieces of 
hardware smaller than the LRV. 
Finally, a subset of images (no more than three per site, usually 
only one) were dropped for each site because NAC derived 
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