![](media/image1.png){width="1.75in" height="0.6416666666666667in"}

The Unified Lunar Control Network 2005

*By* Brent A. Archinal^1^, Mark R. Rosiek^1^, Randolph L. Kirk^1^, and
Bonnie L. Redding^1^

2006

Open-File Report 2006-1367 - Version 1.0

U.S. Department of the Interior

U.S. Geological Survey

U.S. Department of the Interior

Dirk Kempthorne, Secretary

U.S. Geological Survey

Mark Myers, Director

U.S. Geological Survey, Reston, Virginia 2006

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Suggested citation:\
Archinal, B.A., Rosiek, M.R., Kirk, R.L., and Redding, B.L., 2006, The
Unified Lunar Control Network 2005: U.S. Geological Survey Open-File
Report 2006-1367 \[http://pubs.usgs.gov/of/2006/1367/ \].

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Although this report is in the public domain, permission must be secured
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this report.

# Contents {#contents .TOCHeading1}

Contents [iii](#contents)

Figures [iii](#figures)

Tables [iii](#tables)

Abstract [1](#abstract)

Introduction [1](#introduction)

Previous Networks [2](#previous-networks)

ULCN 2005 [2](#ulcn-2005)

Available Files [4](#available-files)

Uses of the ULCN 2005 [6](#uses-of-the-ulcn-2005)

Future Work [8](#future-work)

Acknowledgements [9](#acknowledgements)

References Cited [9](#references-cited)

# Figures {#figures .TOCHeading1}

**Figure 1.** Color-coded topography derived from the ULCN 2005 solution
13

**Figure 2.** Example detail topographic map of the Oppenheimer crater
derived from a TIN of Clementine LIDAR radii (km) and showing the
position of LIDAR measurements. 14

**Figure 3.** Example detail topographic map of the Oppenheimer crater,
derived from a TIN of ULCN 2005 radii (km) and showing the position of
Clementine image tie point measurements.
[16](#refheading___toc143337134)

**Figure 4.** Close up of the topographic model shown in Figure 1, for
the north polar area of the Moon. 16

**Figure 5.** Close up of the topographic model shown in Figure 1, for
the south polar area of the Moon. 16

**Figure 6.** Absolute horizontal difference in the image boresight
position of 43,866 images, between the ULCN 2005 solution and the CLCN
solution. 17

# Tables {#tables .TOCHeading1}

**Table 1.** Lunar Horizontal Control Net Comparison.
[17](#__RefHeading___Toc28259948)

**Table 2.** Vertical Data Sources for the Moon.
[18](#__RefHeading___Toc28259949)

.

The Unified Lunar Control Network 2005

*by* Brent A. Archinal, Mark R. Rosiek, Randolph L. Kirk, and Bonnie L.
Redding [^1]

# Abstract

This report documents a new general unified lunar control network and
lunar topographic model based on a combination of Clementine images and
a previous network derived from Earth based and Apollo photographs, and
Mariner 10 and Galileo images. This photogrammetric network solution is
the largest planetary control network ever completed. It includes the
determination of the 3-D positions of 272,931 points on the lunar
surface and the correction of the camera angles for 43,866 Clementine
images, using 546,126 tie point measurements. The solution RMS is 20 µm
(= 0.9 pixels) in the image plane, with the largest residual of 6.4
pixels. The explanation given here, along with the accompanying files,
comprises the release of the network information and of global lunar
digital elevation models (DEMs) derived from the network. A paper that
will describe the solution and network in further detail will be
submitted to a refereed journal, and will include additional background
information, solution details, discussion of accuracy and precision, and
explanatory figures.

# Introduction

We have completed a new general unified lunar control network and lunar
topographic model based on Clementine images and the previous ULCN
network, which had been derived from Earth-based and Apollo photographs,
and Mariner 10 and Galileo images of the Moon. This photogrammetric
network solution is the largest planetary control network ever
completed. It includes the determination of the 3-D positions of 272,931
points on the lunar surface and the correction of the camera angles for
43,866 Clementine images, using 546,126 tie point measurements. The
solution RMS is 20 µm (= 0.9 pixels) in the image plane, with the
largest residual of 6.4 pixels. We have previously issued progress
reports on this work \[Archinal, et al., 2005a-e, 2006a-c\]. The
explanation given here, along with the accompanying files, comprises the
release of the network information and of global lunar digital elevation
models (DEMs) derived from the network. We also plan to submit a paper
to a refereed journal describing the network in detail. This information
is being released as an Open-File Report prior to such publication due
to its importance in the planning of current and upcoming lunar
missions.

# Previous Networks

In recent years there have been two generally accepted lunar control
networks. These are the Unified Lunar Control Network (ULCN) and the
Clementine Lunar Control Network (CLCN), both derived by M. Davies and
T. Colvin at RAND. The original ULCN was described in the last major
publication about a lunar control network \[Davies, et al., 1994\]. See
Tables 1 and 2 for statistics on this and the other networks discussed
here. Images for this network are from the Apollo, Mariner 10, and
Galileo missions, and Earth-based photographs. This network is important
because (1) its accuracy is relatively well-quantified, (2) it connects
the four different types of image data, and (3) published information on
the network is available.

The CLCN was derived from Clementine images and measurements on
Clementine 750-nm images. The purpose of this network was to determine
the geometry for the Clementine Base Map \[USGS, 1997\]. The geometry of
that mosaic was used to produce the Clementine UVVIS digital image model
\[USGS, 1999; Eliason, et al., 1999\] and the Near-Infrared Global
Multispectral Map of the Moon from Clementine \[USGS, in preparation;
Eliason, et al., 2003\]. Because of the extensive use of these products,
they and the underlying CLCN effectively define the accepted current
coordinate frame for reporting and describing the location of lunar
features. The CLCN is described in print only briefly \[Edwards, et al.,
1996\]. See <http://astrogeology.usgs.gov/Projects/ControlNetworks/> for
further information and ULCN and CLCN files.

Our efforts have merged these two networks into an improved ULCN,
improving greatly upon the accuracy of the CLCN, determining radii for
the CLCN points, further improving the original ULCN, and providing for
a single unified photogrammetrically determined network.

# ULCN 2005

The primary significant feature of our new network in comparison to the
previous ones is that we solve for the radii of the control points. This
avoids distortion of horizontal positions (of about 7 km average, and up
to 15 km or more), that have been pointed out by previous authors
\[Malin and Ravine, 1998; Cook, et al., 2000; Cook, et al., 2002\].
Solution for radii is possible because the overlapping Clementine images
provide stereo information. The expected vertical precision of such
information is generally on the order of several hundred meters, and the
radii derived from the images appear to be compatible with Clementine
LIDAR \[Smith, et al., 1997\], previously the most accurate radii data,
at this level of precision. When the ULCN 2005 solution radii of all
272,931 control points are compared to the a priori radii derived from
an interpolation of a combination of Clementine LIDAR and polar
Clementine stereo data \[Rosiek, et al., 2001\], the differences are not
significant. Specifically, the mean absolute difference of the solution
radii from their a priori values is 137 m, with a standard deviation of
219 m, thus showing there is no systematic difference between the LIDAR
and newly derived values, and that the radii must therefore be of
similar accuracy (a few hundred meters). Thus a by-product of this
network is a global lunar topographic model that is denser than that
provided by LIDAR and of similar accuracy. Only in limited areas of the
Moon are higher density topographic data available \[Rosiek, et al.,
1998; Rosiek, et al., 1999; Rosiek and Aeschliman, 2001; Rosiek, et al.,
2001; see <http://astrogeology.usgs.gov/Projects/ISPRS/MEETINGS/>;
Margo, 1999; Margo, et al., 1999 and 2000; Wu and Doyle, 1990\]. With
272,931 control points, and assuming a spherical moon with radius =
1737.4, there is an average of one point for every \~46 km^2^, or one
point every \~6.8 km. This radius information is also defined in a
consistent, full, absolute, 3D frame. This is the only lunar topographic
model where both height and horizontal positions are estimated in a
globally-consistent frame. See Figure 1 for a representation of this
topographic model. Figures 2 and 3 compare, for the area of the
Oppenheimer crater, results from Clementine LIDAR and the ULCN 2005 DEM
model. Figures 4 and 5 show perspective views of the ULCN 2005 DEM in
the areas of the north and south pole of the Moon.

A second significant feature of the ULCN 2005 is that we have used a
constraint for the camera angles of 1º, although we have allowed angles
that show changes of more than 0.6º to change freely. This is on the
assumption that angles with such large changes result from angle
measurement errors (a few angles change by up to \~25º, probably due to
unaccounted for spacecraft operations). The constraint of 1º is quite
conservative in comparison to the much greater accuracy with which the
angles were measured, i.e. reportedly 0.03º \[Nozette, et al., 1994\].
We believe this feature provides significant improvement in the
horizontal accuracy of the network (and therefore in the vertical
accuracy, which is coupled), because we have substantially eliminated
apparent large errors that exist in the original camera angle
measurements, while allowing for minor (and generally expected)
adjustments in the angles. Note that from an average altitude of 640 km,
the implied horizontal position accuracy due to the 0.03º accuracy of
the a priori information is 335 m. Because 99% of the angles change less
than 0.45º, this and the 640 km altitude would also imply that even if
the a priori angles were perfect, the greatest 3 standard deviation
horizontal error in our solution could not exceed 5.1 km. This also
assumes that the spacecraft positions -- which we do not adjust -- are
perfectly accurate. Obviously, this is not the case, but the cited
errors \[Zuber, et al., 1994\] in the orbit positions (at least
radially) are \~100 m, which when root square sum added to the pointing
errors, would still cause additional errors of a maximum of a few
hundred meters. The change (and therefore improvement) in camera
boresight positions between the CLCN and ULCN 2005 is represented in
Figure 6. Because the estimated errors in the CLCN solution are so much
larger than those of the ULCN 2005, this is also effectively a map of
the improvement in the control network.

A third feature of the ULCN 2005 is that a majority of the original ULCN
points were identified on Clementine images and their measurements were
included in the new ULCN 2005. 1,261 points were measured, and 754 of
them were measured on two or more images. This therefore allows for the
direct incorporation of the ULCN into the new ULCN 2005. We have done so
by weighting the ULCN points appropriately (0.18-5 km horizontally, 2-6
km vertically) for the accuracies as described in \[1\]. A subset
containing 124 ULCN points, that had particularly high residuals, was
interpreted as consisting of misidentified points or points where the
original ULCN was in error. These points were subsequently weighted the
same as non-ULCN points (2 km horizontally and 10 km vertically, or
effectively free to adjust). This tie to the ULCN and the use of
Clementine a priori spacecraft position data in the mean Earth/polar
axis system also places our solution in that same mean Earth/polar axis
system (see Davies, et al. \[1994\]).

# Available Files

The files accompanying this text explanation comprise the ULCN 2005
solution input and output files, and derived files of interest. An
accompanying file, "ReadMe-ULCN2005.txt" describes all the files in
detail. However, here we summarize those files and provide suggestions
for their possible use.

The directory structure used for the files separates them into three
categories: 1) solution input and output files (sub directory
"solution"); 2) Miscellaneous derived files of interest ("derived"); and
3) global DEMs and DEM images ("dems"). Where appropriate, text
explanations of file formats are also included as ASCII (ASC) and Adobe
Acrobat (PDF) files.

The solution input and output files include (in ASCII format) the tie
point measurement file and the primary output file. The latter includes
ULCN 2005 solution control point positions and camera angles (the latter
accompanied by the input image numbers, times, and spacecraft
positions). The control point positions define the global DEM, from
which the DEM files described below are derived.

Miscellaneous derived files include: 1) A list of the sorted solution
residuals, from the last iteration, which could be used to characterize
the precision of the control point positions; and 2) the calculated
statistics for each control point, including in particular the minimum
expected vertical precision at each point. This latter file includes the
image resolution at each point, which could be used with the residual
information to estimate the (residual) uncertainty for each control
point measurement in meters.

The global DEM files are derived from the control point positions. Two
types of DEM files are provided in multiple formats. All of the DEMs are
in global simple cylindrical projection.

The following types of DEMs were produced:

1.  The first DEM is at a resolution of 16 pixels/degree (e.g. about
    1.895 km resolution), as a grid created from a triangle irregular
    network (TIN) of the original points. Note that no smoothing has
    been done to the points, so at the meter to tens of meters level
    significant noise (e.g. due to orbit errors and varying vertical and
    horizontal precision) can be seen in this DEM particularly if
    "hill-shading" is applied. However, in any given local area, the
    user may find this to be the most accurate representation of
    topography. This format was created using ESRI™ ArcMap™ 3D Analyst™
    functions.

2.  A second DEM is also at a resolution of 16 pixels/degree (e.g. about
    1.895 km resolution), as a grid created from a polynomial fit
    through the original points. For many users this will be the most
    useful DEM representation because the algorithm smoothes the sub
    areas and gives the most aesthetically pleasing DEM. However, users
    should be cautioned that the smoothing does attenuate the topography
    in some areas where only one point indicates a local high or low
    radius, for example. This format was created using ArcMap™
    Geostatistical Analyst function.

The DEMs have been produced in the following formats:

-   ISIS cube files.

-   A BIL ("band interleaved by line" format) header that can be used
    with the ISIS cube files by changing the file extension from .cub to
    .bil.

-   ArcMap™ grids.

-   ArcMap™ ASCII grid files.

-   TIFF image files.

A simple ASCII listing file has also been included. This includes, for
each ULCN 2005 control point the following information:

**Pt_name** - point name. The 22 points that tied the ULCN to the CLCN
are place or feature names (i.e. Clerke). Other points from the ULCN are
either a number (i.e. 655) or start with M or P and then a number (P7084
or M5). These later names are from the original ULCN \[Davies, et al.,
1994\], with the "P" points being from the Catalog of Lunar Positions
based on the Lunar Positional Reference System (1974) that was published
by the Defense Mapping Agency. The "M" points are Mariner 10 points. The
Clementine points are 2 letters, 4 numbers, and then 1 letter (i.e.
AF0510C, in a rather arbitrary system use to number points on Clementine
images).

**set** - a number 1-5 indicating the data source (1 - Apollo Network,
2 - Telescopic Network, 3 - Mariner 10 Network, 4 - Galileo Network, and
5-CLCN)

**measures -** number of measurements on a point

**evp_m** - expected vertical precision in meters

**lat -** latitude (degrees) from final solution of ULCN2005

**lon_360** - longitude (degrees) in positive east 360 longitude system
from final ULCN2005 solution

**lon_180 -** longitude (degrees) in positive east ±180 longitude system
from final ULCN2005 solution

**radius_km -** radius value for point in kilometers from final ULCN2005
solution

**ht_m -** height in meters referenced to a sphere of 1,737,400 meters
based on radius_km value **lpo_ht -** height in meters referenced to a
sphere of 1,737,400 meters based on interpolating a grid using a local
polynomial interpolator on the radius_km values

**lpo_diff -** difference between the lpo_ht and the ht_m

**grid_ht -** height in meters referenced to a sphere of 1,737,400
meters based on interpolating a grid using a bilinear interpolator
between the radius_km values

**grid_dif -** difference between the grid_ht and the ht_m

**NOTE:** Radii (km) and height values may not be equal due to: (1)
round off from real to integer value; (2) multiple points in the same
grid cell; (3) smoothing; and (4) interpolation.

[]{.mark}

We caution that it has been challenging to make DEMs from the ULCN 2005
control point solution due to the irregular distribution of the data,
the sparseness of the data (compared to, for example, using MOLA data
from Mars), and the highly variable precision of the control point
positions (due to the varying stereo geometry). For users who wish to
obtain the highest accuracy from this dataset for a given area, we
recommend starting from the original set of control points, checking the
size of the residuals for the control point measurements and the
expected vertical precision of the control points, and examining and
possibly editing/filtering/smoothing the data in the area of interest to
remove outliers. Most likely, the best accuracy of the data will still
be in the few hundred meter range, if only due to the uncertainty in the
Clementine spacecraft positions, although the relative accuracy between
adjacent and nearby points may be much better, as indicated by the
expected vertical precision information.

# Uses of the ULCN 2005

We envision multiple possible uses for the ULCN 2005 control network and
topographic model. The original reason that we updated the CLCN solution
was because it contained significant (several km) horizontal errors,
which were noted in it during the late 1990s and early 2000s. Our hope
was that the updated solution could be used to correct positions
measured from the USGS Clementine mosaics -- which to some extent has
become a default source for coordinates of lunar features -- or that
some or all of these mosaics could be remade using the new network.

It is now clear that there are a number of other possible uses for the
ULCN 2005 solution information, particularly since we have been able to
recover control point radii, a significantly dense set of topographic
information. We summarize here some of the most significant uses.

1.  The change in control point coordinates (or somewhat equivalently
    the image boresight positions) from the CLCN to the ULCN 2005
    defines a transformation field. With appropriate software that
    information could be used to convert ("warp", "rubber sheet", etc.)
    coordinates from the old CLCN and Clementine mosaic frame to the
    (more accurate) ULCN 2005 frame. This would allow the positions of
    features of interest (e.g. scientific/geologic or operational for
    landing site selection) to be determined as accurately as possible.
    This could also be done with portions or all of the Clementine
    mosaics (the Clementine Base Map, UVVIS, or Near-Infrared Global
    Multispectral Map). We have had some success in transforming small
    areas of the Clementine Base Map mosaic using ArcInfo Workstation by
    ESRI. Other publicly and commercially available tools could also be
    used for such work (e.g. ISIS, ENVI by ITT Visual Information
    Solutions, GDAL).

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3.  The Clementine mosaics could be rigorously regenerated using the new
    network, thus removing the large scale distortions in them so that
    positions could be accurately measured directly from the mosaics.
    The regeneration process would also be an opportunity to introduce
    other improvements to these mosaics, such as improving the
    radiometric calibration, changing the tiling scheme to using larger
    file sizes, and projecting the images onto the ULCN 2005 topography,
    thereby creating a true orthomosaic rather than a mosaic projected
    onto a sphere. In addition, the regeneration process could be done
    in such as way that it could easily be repeated in the future. That
    will be necessary as the control network continues to be improved
    with new mission data and while users still require registration
    between old and new datasets at the sub-pixel level. It is true that
    taking advantage of these opportunities will require significant
    funding, although not approaching the cost of the original creation
    of the mosaics. However, there will also be substantial savings in
    the future for users of the mosaics (since they will not need to
    maintain software and do coordinate conversions) when either using
    the mosaics or geometrically improving them further.

4.  Because this improved network is now available, we will tie the
    Lunar Orbiter global digital mosaic now being generated to this
    network \[Becker, et al., 2005; Weller, et al., 2006; see
    <http://astrogeology.usgs.gov/Projects/LunarOrbiterDigitization/>\].
    Tie point measurements are being made between the Lunar Orbiter
    images and an independent global lunar orbiter test network is being
    created from those measures. Tie points are also being measured
    between the Lunar Orbiter images and some of the Clementine images
    in the ULCN 2005 -- thus allowing the Lunar Orbiter images to be
    positioned in an absolute sense into the same ULCN 2005 frame.

5.  The vertical positions of the ULCN 2005 points now provide a global
    topographic model for the Moon with a more uniform distribution of
    points compared to existing topographic information, such as the
    non-polar LIDAR data, the Clementine polar stereo data from Rosiek
    et al \[1998, 1999, Rosiek and Aeschliman, 2001; 2001\], and the
    (unreleased) irregular Clementine stereo data from Cook, et al.
    \[2000\]. Though such a DEM is nowhere near as dense or as accurate
    as, for example, those generated from the MOLA data at Mars, it will
    serve as the best global topography model for the Moon until it is
    supplanted in a few years with new data. In any case, such a global
    DEM obviously has diverse uses, such as:

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a.  Assisting in studies of global and regional geology and morphology
    of the Moon, including the investigation of the Moon's impact basins
    and larger craters.

b.  Providing a surface onto which oblique images can be orthorectified,
    in order to remove image distortions due to topographic effects.

c.  Providing operational information for near-term lunar operations,
    e.g. for the planning of the acquisition of new imaging and other
    (e.g. altimeter) data (SELENE, Chang'E-1, Chandrayaan-1, LRO), and
    the determination of lunar radius in areas planned for possible
    landings (the U.S. planned 2011 LPRP lander) or impacts (e.g.
    SMART-1 in 2006, LCROSS in 2008). Because the Lunar Orbiter mosaic
    will be tied to this network, users could determine horizontal
    positions of features of interest from that mosaic. Then the
    approximate radii at those locations could be determined using the
    ULCN 2005 derived DEM. As an example of this, the DEM was used along
    with the Clementine stereo models of Cook, et al. (Anthony Cook,
    Thomas Watters, and Mark Robinson) to predict possible impact points
    for the SMART-1 spacecraft on 2006 September 3. The orbit of the
    spacecraft was raised several hundred meters on the basis of this
    information so the impact would occur on the orbit best suited for
    Earth-based observation. The impact also appears to have occurred
    within a few hundred meters of where it was predicted via the ULCN
    2005 and Cook, et al. stereo data. \[See e.g.
    <http://www.esa.int/SPECIALS/SMART-1/SEMV386LARE_0.html> and
    <http://www.esa.int/SPECIALS/SMART-1/SEMWX03VRRE_1.html>\].

d.  The global ULCN 2005 DEM can also be used for registering other
    regional or local topographic information. For example, we are
    working with Cook, et al. to register their "planet-wide" Clementine
    DEMs into this frame, so this Clementine stereo information can
    finally be easily used. Other DEMs, such as those derived from the
    digitization of old maps \[Willoughby, et al., 2004\] or new
    processing of Lunar Orbiter or Apollo imagery \[Rosiek, et al.,
    2006a-c\] can also be registered to this frame so that the internal
    coordinates will be accurate at the level of the ULCN 2005 itself
    (e.g. the few hundred meter level, rather than with the several
    kilometers of error that some of these DEMs currently have).

e.  The tie point measurements used in the ULCN 2005 can be used to
    locate the specific control point locations on the Clementine
    images, and through interpolation, to estimate the coordinates of
    intermediate points in the ULCN 2005 frame.

f.  Individual Clementine images used in the ULCN 2005 can also now be
    projected onto the UCLN 2005 DEM and - with the appropriate software
    (e.g. ISIS) - points of interest can be identified and measured in
    three dimensions directly.

g.  Finally, the ULCN 2005 network can serve as a base for tying other
    existing imagery (e.g. Earth-based, Lunar Orbiter, Apollo, Mariner
    10, Galileo, other Clementine images, SMART-1 images) and future
    imagery and data. This type of use is discussed further in the next
    section.

# Future Work

We are already at work on an improved version of the ULCN 2005
(tentatively to be called the ULCN 2007). This will be a new solution,
incorporating additional datasets. We are checking the Mariner 10 and
Galileo \[Belton, et al., 1992, 1994; Schenk and Bussey, 2004\] image
measurements already used in the ULCN, and directly incorporating them
into the solution instead of relying on the constraints on the original
ULCN \[Davies, et al., 1994\] points. We will, however, continue to use
constrained positions for the original ULCN points based on Apollo and
Earth based imagery, rather than reanalyzing these extensive sub
networks. We also plan to directly incorporate the Lunar Orbiter image
measurements. Because of their wide area of coverage relative to image
size (in comparison to Clementine images) we expect that adding the
earlier images will strengthen the horizontal accuracy of the network,
both regionally where the Mariner 10 and Galileo imagery exist, and
globally in the case of the Lunar Orbiter imagery. We are adding ties to
the current absolute reference frame described by the Lunar Laser
Ranging (LLR) and Apollo Lunar Science Experiment Package (ALSEP)
network \[Davies and Colvin, 2000\]. This should further improve the
accuracy of the network in the vicinity of the Apollo landing sites. The
merging of these datasets should not only improve the horizontal and
vertical accuracy and density of the global network, but *places all of
the data* (e.g. Lunar Orbiter, Mariner 10, Galileo, Clementine, and to
some extent Apollo) *into a common network* (reference frame).

We also plan to "densify" the available topographic information. First,
we will attempt to interpolate our camera angle solutions to the time of
the LIDAR observations in order to correct the spacecraft pointing for
the LIDAR data. This should then allow a direct merging of the LIDAR and
our ULCN 2005 (or later solution) topographic information, e.g.
increasing the number of points to (272931 plus 72548) \~345,479. As
already described, we are working with Cook, et al. (2000, 2002) to take
their "planet-wide" Clementine stereo information and register it into
the ULCN 2005 and its successor solutions. Not only will the expected
vertical precision of the derived radii will generally be significantly
better than the ULCN 2005 radii, in regions where the data exists the
density of such points will be increased by \~2 orders of magnitude.

In the long term, there are a number of options for further improving
the lunar network and topography that we will attempt as funding
permits. This would include the continuing incorporation of past
datasets, such as the Apollo images, the Rosiek et al. Clementine polar
stereo, and Earth-based radar information.

The larger and more important challenge will be to incorporate data from
all of the current and planned missions. This is necessary so that these
new datasets can be compared among themselves and to prior data,
particularly the Lunar Orbiter global mosaic and the Clementine
multispectral products. Interested readers are referred to our recent
review \[Kirk, et al., 2006\] of past, present, and planned future lunar
mapping efforts, which includes detailed recommendations for future
work.

# Acknowledgements

We acknowledge the efforts of Tim Colvin and the late Merton Davies of
RAND for their development of the ULCN and CLCN and for the algorithms
and software used. This work is partially funded through the NASA
Planetary Geology and Geophysics Program.

# References Cited

Archinal, B. A., M. R. Rosiek, and B. L. Redding (2005a). "Unified Lunar
Control Network 2005 and Topographic Model," *Lunar Planetary Sci.*,
XXXVI, Lunar and Planetary Institute, Houston, abstract no. 2106
\[CD-ROM\].

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2005b).
"Improved Lunar Control and Topography**,** *AAS Division of Planetary
Sciences meeting*," September 4-9, Cambridge, UK. Abstract.

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2005c).
"Update on the Unified Lunar Control Network 2005," *Space Resources
Roundtable VII: LEAG Conference on Lunar Exploration*, October 25 -- 28,
League City, Texas. Abstract no. 2061.

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2005d).
"Unified Lunar Topographic Model," *Space Resources Roundtable VII: LEAG
Conference on Lunar Exploration*, October 25 -- 28, League City, Texas.
Abstract no. 2060.

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2005e).
"Unified Lunar Control Network 2005 - A Global 3-D Photogrammetric
Network**,"** *Eos Trans. AGU***,** 86(52), Fall Meet. Supplement,
Abstract G53C-01.

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2006a).
"Completion of the Unified Lunar Control Network 2005 and Topographic
Model," *Lunar Planet. Sci.,* XXXVII, Abstract 2310, Lunar and Planetary
Institute, Houston (CD-ROM). \[Note that a possible 700 m bias in point
radii mentioned in this abstract has been resolved -- no such bias
exists now between UCLN 2005 radii and Clementine LIDAR radii.\]

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2006b). "A
Clementine Derived Control Network and Topographic Model - The Unified
Lunar Control Network 2005," *XXVIth IAU General Assembly*, Session
JD10, Prague, August 14-25, 2006, abstract 2332, accepted.

Archinal, B. A., M. R. Rosiek, R. L. Kirk, and B. L. Redding (2006c). "A
report on the Unified Lunar Control Network 2005 and lunar topographic
model," *Europlanet #1, European Planetary Science Congress 2006*,
Berlin, Germany, September 18-22, 2006. Submitted.

Becker, T., L. Weller, L. Gaddis, D. Soltesz, D. Cook, B. Archinal, A.
Bennett, T. McDaniel, B. Redding, and J. Richie (2005). **"**Lunar
Orbiter Revived: Update on Final Stages of Scanning, Archiving, and
Cartographic Processing at USGS**,"** *Lunar Planet. Sci.*, XXXVI: Lunar
and Planetary Institute, Houston, Abstract no. 1836 \[CD-ROM\].

Belton, M. J. S., et al. (1992). "Lunar impact basins and crustal
heterogeneity---New western limb and far side data from Galileo,"
*Science*, 255, 570--576.

Belton, M. J. S., et al. (1994). "Galileo multispectral imaging of the
north polar and eastern limb regions of the Moon," Science, 264,
1112--1115.

Cook, A.C., T. R. Watters, M. S. Robinson, P. D. Spudis, and D. B. J.
Bussey (2000). "Lunar polar topography derived from Clementine stereo
imagery," *JGR*, 105, no. E5, Pages 12,023-12,033, May 25.

Cook, A. C., M. S. Robinson, B. Semenov, and T. R. Watters (2002).
"Preliminary Analysis of the Absolute Cartographic Accuracy of the
Clementine UVVIS Mosaics," American Geophysical Union, Fall Meeting
2002, Abstract no. P22D-09. Presentation available at
<http://astrogeology.wr.usgs.gov/Teams/Geomatics/geodesy/davies.html>.

Davies, M. E., T. R. Colvin, D. L. Meyer, and S. Nelson (1994). "The
unified lunar control network: 1994 version," *JGR*, 99, no. E11, Pages
23,211-23,214. November 25.

Davies, M. E., and T. R. Colvin (2000). "Lunar coordinates in the
regions of the Apollo landers," *JGR*, 105, no. E8, pp. 20,277-20,280,
August 25.

Edwards, K. E., T. R. Colvin, T. L. Becker, D. Cook, M. E. Davies, T. C.
Duxbury, E. M. Eliason, E. M. Lee, A. S. McEwen, H. Morgan, M. S.
Robinson, and T. Sorensen (1996). "Global Digital Mapping of the Moon,"
*Lunar Planet. Sci.*, XXVII: Houston, Lunar and Planetary Institute,
335.

Eliason, E. M., A. S. McEwen, M. S. Robinson, E. M. Lee, T. Becker, L.
Gaddis, L. A. Weller, C. E. Isbell, J. R. Shinaman, T. Duxbury, E.
Malaret (1999). "Digital processing for a Global Multispectral Map of
the Moon from the Clementine UVVIS Imaging Instrument," *Lunar Planet.
Sci.*, XXX: Lunar and Planetary Institute, Houston, Abstract no. 1933
\[CD-ROM\].

Eliason, E. M., E. M. Lee, T. L. Becker, L. A. Weller, C. E. Isbell, M.
I. Staid, L. R. Gaddis, A. S. McEwen, M. S. Robinson, T. Duxbury, D.
Steutel, D. T. Blewett, and P. G. Lucey (2003). "A Near-Infrared (NIR)
Global Multispectral Map of the Moon from Clementine," *Lunar Planet.
Sci.*, XXXIV: Lunar and Planetary Institute, Houston, Abstract no. 2093,
\[CD-ROM\].

Isbell, C. E., E. M. Eliason, T. Becker, E. M. Lee, A. McEwen, and M.
Robinson (1997). "The Clementine Mission: an Archive of a Digital Image
Model of the Moon," *Lunar Planet. Sci.*, XXVIII: Lunar and Planetary
Institute, Houston, p. 623.

Kirk, R. L., B. A. Archinal, L. R. Gaddis, and M. R. Rosiek (2006).
"Cartography for Lunar Exploration: 2006 Status and Planned Missions,"
*International Archives of Photogrammetry, Remote Sensing and Spatial
Information Sciences*, XXXVI, Part 4, \"Geospatial Databases for
Sustainable Development\", Goa (CD-ROM).

Malin, M. and M. Ravine (1998). *Clementine High Resolution Camera
Mosaicking Project*, TR, Malin Space Science Systems San Diego.

Margot, J-L. C. (1999). *Lunar topography from earth-based radar
interferometric mapping*, PhD Thesis, Cornell University.

[Margot, J-L.](http://adsabs.harvard.edu/cgi-bin/author_form?author=Margot,+J&fullauthor=Margot, J. L.&charset=UTF-8&db_key=AST)*,*
D. B.
[Campbell](http://adsabs.harvard.edu/cgi-bin/author_form?author=Campbell,+D&fullauthor=Campbell, D. B.&charset=UTF-8&db_key=AST),
R. F. [Jurgens, and M.
A.](http://adsabs.harvard.edu/cgi-bin/author_form?author=Jurgens,+R&fullauthor=Jurgens, R. F.&charset=UTF-8&db_key=AST)
[Slade](http://adsabs.harvard.edu/cgi-bin/author_form?author=Slade,+M&fullauthor=Slade, M. A.&charset=UTF-8&db_key=AST)
(1999). "Topography of the lunar poles from radar interferometry: A
survey of cold trap locations," *Science*, 284, pp. 1658-1660.

[Margot, J-L.](http://adsabs.harvard.edu/cgi-bin/author_form?author=Margot,+J&fullauthor=Margot, J. L.&charset=UTF-8&db_key=AST)*,*
D. B.
[Campbell](http://adsabs.harvard.edu/cgi-bin/author_form?author=Campbell,+D&fullauthor=Campbell, D. B.&charset=UTF-8&db_key=AST),
R. F. [Jurgens, and M.
A.](http://adsabs.harvard.edu/cgi-bin/author_form?author=Jurgens,+R&fullauthor=Jurgens, R. F.&charset=UTF-8&db_key=AST)
[Slade](http://adsabs.harvard.edu/cgi-bin/author_form?author=Slade,+M&fullauthor=Slade, M. A.&charset=UTF-8&db_key=AST)
(2000). "Digital elevation models of the Moon from Earth-based radar
interferometry," IEEE Trans. on Geoscience and Remote Sensing, 38, no.
2, pp. 1122-1133.

Nozette, S., and 34 others (1994). "The Clementine mission to the Moon,"
*Science*, 266, pp. 1835-1839, 16 December.

Rosiek, M. R., R. L. Kirk, and E. T. Howington-Kraus (1998). "Lunar
topographic maps derived from Clementine imagery," *Lunar Planet. Sci.*,
XXX: Lunar and Planetary Institute, Houston, Abstract no. 1853
\[CD-ROM\].

Rosiek, M. R., R. L. Kirk, and E. T. Howington-Kraus (1999). "Lunar
topographic maps derived from Clementine imagery," *Lunar Planet. Sci.*,
XXX: Houston, Lunar and Planetary Institute, abstract no. 1853
\[CD-ROM\].

Rosiek, M. R, and R. A. Aeschliman (2001). "Lunar shaded relief map
updated with Clementine data," *Lunar Planet. Sci.*, XXXII: Lunar and
Planetary Institute, Houston, Abstract no. 1943 \[CD-ROM\].

Rosiek, M. R., R. L. Kirk, and E. T. Howington-Kraus (2001). "Combining
lunar photogrammetric topographic data with Clementine LIDAR data,"
*Planetary Mapping 2001*, International Society for Photogrammetry and
Remote Sensing, Working Group IV/9: Flagstaff, Arizona, web publication,
available at
<http://astrogeology.usgs.gov/Projects/ISPRS/MEETINGS/Flagstaff2001/index.html>.

Rosiek, M. R., B. A. Archinal, R. L. Kirk, T. L. Becker, L. Weller, B.
Redding, E. Howington-Kraus, and D. Galuszka (2006a). "Utilization of
Digitized Apollo and Lunar Orbiter Imagery for Mapping the Moon," *Lunar
Planet. Sci.,* XXXVII, Abstract 2171, Lunar and Planetary Institute,
Houston (CD-ROM).

Rosiek, M. R., R. L. Kirk, B. A. Archinal, T. L. Becker, L. Weller, B.
Redding, E. Howington-Kraus, and D. Galuszka (2006b). "Using Digitized
Spacecraft Film and a Revised Lunar Control Network for Photogrammetric
Mapping," ASPRS 2006 Annual Conference, Reno, Nevada, May 1-5.

Rosiek, M. R., R.L. Kirk, B.A. Archinal, L. R. Gaddis, T.L. Becker, L.
Weller, B. Redding, E. Howington-Kraus, and D. Galuszka (2006c). "Lunar
Mapping with Digitized Apollo and Lunar Orbiter Imagery," *ISPRS
International Archives of Photogrammetry, Remote Sensing and Spatial
Information Sciences*, XXXVI, part 4, submitted.

Schenk, P. M., and D. B. J. Bussey (2004). "Galileo stereo topography of
the lunar north polar region," *Geophys. Res. L*., 31, L23701, 4 pp.

Smith, D. E., M. T. Zuber, G. A. Neumann, and F. G. Lemoine (1997).
"Topography of the Moon from the Clementine LIDAR," *JGR*, 102, no. E1,
p. 1591--1611.

USGS (1997). *Clementine Basemap Mosaic*, USA_NASA_PDS_CL_30xx, NASA
Planetary Data System.

USGS (1999). *Clementine UVVIS Mosaic*, USA_NASA_PDS_CL_40xx, NASA
Planetary Data System.

USGS (2002). *Color-Coded Topography and Shaded Relief Maps of the Lunar
Hemispheres*, Geologic Investigations Series I-2769, U. S. Geological
Survey.

Weller, L., B. Redding, T. Becker, L. Gaddis, R. Sucharski, D. Soltesz,
D. Cook, B. Archinal, A. Bennett, and T. McDaniel (2006). "Lunar Orbiter
Revived: Very High Resolution Views of the Moon," *Lunar Planet. Sci.*,
XXXVII: Lunar and Planetary Institute, Houston, Abstract no. 2143
\[CD-ROM\].

Willoughby, N. J., A. C. Cook, and M. S. Robinson (2004).
"Semi-Automated Extraction of Contours from Lunar Topographic Maps,"
*Lunar Planet. Sci.*, XXXV: Lunar and Planetary Institute, Houston,
Abstract no. 2040 \[CD-ROM\].

Wu, S. S. C. and F. J. Doyle (1990). "Topographic Mapping," in
*Planetary Mapping,* R. Greeley and R.M. Batson, eds., Cambridge
University Press, Cambridge, 169--207.

Zuber, M. T., D. E. Smith, F. G. Lemoine, and G. A. Neumann (1994). "The
Shape and Internal Structure of the Moon from the Clementine Mission,"
Science, 266, 1839-1843, 16 December.

![](media/image2.jpeg){width="6.5in" height="3.8402777777777777in"}

**Figure 1.** Color-coded topography derived from the ULCN 2005
solution. The topographic information is superimposed on the USGS shaded
relief airbrush map of the Moon. This constitutes an improved lunar
topographic model, the densest such global model existing. The
topography is derived from smoothing the solution radii of all 272,931
control points, using a priori radii derived from an interpolation of a
combination of Clementine LIDAR and polar Clementine stereo data. The
mean absolute difference of these radii from their a priori radii is 137
m, with a standard deviation of 219 m, thus showing there is no
systematic difference between the LIDAR and newly derived values, and
that the radii must therefore be of similar accuracy (a few hundred m).
Camera angles were constrained to 1° of their a priori (NAIF values),
with angles changing by more than 0.6° left free. 99% of the image
boresight directions change by less than 0.45 degrees (\~5.1 km on the
Moon, from the average 640 km altitude). 1,261 of the points are also
UCLN (1994) points, of which 1,137 were constrained (0.18 -- 5 km
horizontally, 2-6 km vertically) to their ULCN positions. The overall
ULCN 2005 solution RMS is 20 micrometers (= 0.9 pixels) in the image
plane, with a largest residual of 6.4 pixels. The map here is a global
simple cylindrical projection with north up and east to the right, 0°
longitude at center, and a 30° spacing longitude and latitude grid.

![](media/image3.jpeg){width="4.279166666666667in"
height="2.8270833333333334in"}

**Figure 2.** Example detail topographic map of the Oppenheimer crater
(193.7° east longitude, 35.2° south latitude, in the northern part of
the South Pole -- Aitken basin), derived from a TIN of Clementine LIDAR
radii (km) and showing the position of LIDAR measurements. Due to the
sparseness of the LIDAR data, note the general lack of correlation
between interpolated elevation and surface features, except for the
overall low of Oppenheimer. Simple cylindrical projection with north up
and east to the right, with USGS shaded relief airbrush lunar map as
background.

[]{#refheading___toc143337134
.anchor}![](media/image4.jpeg){width="4.279166666666667in"
height="2.85in"}

**Figure 3.** Example detail topographic map of the Oppenheimer crater,
derived from a TIN of ULCN 2005 radii (km) and showing the position of
Clementine image tie point measurements. Compare to Figure 2. With the
increased density of ULCN 2005 points, note the good correlation between
elevation and surface features, particularly for the central portion of
the Oppenheimer crater and some of the smaller craters and mountains
around the crater. Simple cylindrical projection with north up and east
to the right, with USGS shaded relief airbrush lunar map as background.

![](media/image5.jpeg){width="3.7979166666666666in"
height="2.963888888888889in"}

**Figure 4.** Close up of the topographic model shown in Figure 1, for
the north polar area of the Moon. Color-coded topographic information
(using the same coding as in Figure 1) is shown with the USGS shaded
relief airbrush map in the background, but projected onto topography
with 10x exaggeration. Meridians of longitude are shown every 30° and
are projected onto the topography. The 210° east longitude meridian is
in the right foreground. The correspondence between the newly-derived
absolute topography and the shaded relief topographic representation
appears reasonable.

![](media/image6.jpeg){width="3.8291666666666666in" height="2.975in"}

**Figure 5.** Close up of the topographic model shown in Figure 1, for
the south polar area of the Moon. The 90° east longitude meridian is in
the right foreground.

![](media/image7.jpeg){width="6.663194444444445in"
height="3.1666666666666665in"}

![](media/image8.png){width="3.026388888888889in"
height="0.4131944444444444in"}

**Figure 6.** Absolute horizontal difference (m) in the image boresight
position of 43,866 images, between the ULCN 2005 solution and the CLCN
solution. This demonstrates the approximate horizontal position
improvement of the ULCN 2005 over the CLCN. Shown as a global
rectangular projection with north up and east to the right, and 0°
longitude at center.

+------------+------------+------------+---------------+---------------+
| Name       | Number of  | Number of  | Horizontal    | Vertical      |
|            | points     | images     | Accuracy      | Accuracy      |
+------------+------------+------------+---------------+---------------+
| ULCN       | 1,478      | n/a        | 100 m to 3 km | Few km?       |
+------------+------------+------------+---------------+---------------+
| CLCN       | 271,634    | 43,871     | Few km to     | Sphere        |
|            |            |            | some\>15 km   |               |
+------------+------------+------------+---------------+---------------+
| ULCN 2005  | 272,931    | 43,866     | \~100 m to    | \~100's       |
|            |            |            | few km        |               |
|            |            |            |               | meters        |
+------------+------------+------------+---------------+---------------+

[]{#__RefHeading___Toc28259948 .anchor}**Table 1.**  Lunar Horizontal
Control Net Comparison.

  ---------------- ---------------- ---------------- ---------------------
  Name             Number of points Vertical         Comments
                                    Accuracy         

  ULCN             1,286            Few km?          Sparse, mostly
                                                     nearside

  Clem. LIDAR      72,548           130 m            Sparse, between ±75°

  Clem. polar      3,198,240        \~1-2 km         Polar only
  stereo                            absolute         

  Clem. stereo     not released     Few km absolute  Random coverage

  Earth radar      \~33.8x10^6^     Few km absolute  Polar and Tycho only

  Apollo LIDAR     5,629            Few km?          \<20% coverage

  Apollo stereo    Contour maps     As above         \<20% coverage

  ULCN 2005        272,931          \~100's m        Global uniform
                                                     coverage
  ---------------- ---------------- ---------------- ---------------------

[]{#__RefHeading___Toc28259949 .anchor}**Table 2.**  Vertical Data
Sources for the Moon.

[^1]: 2255 N. Gemini Drive, Flagstaff, AZ 86001, USA,
    <barchinal@usgs.gov>