Astrogeology Science Center

LRO LOLA Elevation Model 118m (LDEM GDR)

This digital elevation model (DEM) is based on data from the Lunar Orbiter Laser Altimeter (LOLA; Smith and others, 2010), an instrument on NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft (Tooley and others, 2010). The created DEM represents more than 6.5 billion measurements gathered between July 2009 and July 2013, adjusted for consistency in the coordinate system described below, and then converted to lunar radii (Mazarico and others, 2012). Elevations were computed by subtracting the lunar reference radius of 1737.4 km (Archinal and others, 2011; LRO Project and LGCWG, 2008) from the surface radius measurements. Thus elevation values are the distance above or below the reference sphere. The average accuracy of each point after crossover correction is better than 20 meters in horizontal position and ~1 meter in radius (Mazarico and others, 2012). The measurements were converted into a digital elevation model (DEM; Neumann and others, 2010) using Generic Mapping Tools software (Wessel and Smith, 1998), with a resolution of 256 pixels per degree. In projection, the pixels are 118 meters in size at the equator. Gaps between tracks of 1–2 km are common, and some gaps of up to 4 km occur near the equator. DEM points located in these gaps in LOLA data were filled by interpolation (Smith and others, 2011).

* Archinal, B.A. (Chair), A’Hearn, M.F., Bowell, E., Conrad, A., Consolmagno, G.J., Courtin, R., Fukushima, T., Hestroffer, D., Hilton, J.L., Krasinsky, G.A., Neumann, G.A., Oberst, J., Seidelmann, P.K., Stooke, P., Tholen, D.J., Thomas, P.C. and Williams, I.P. (2011), Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009, Celestial Mechanics and Dynamical Astronomy, 109, no. 2, February, pp. 101-135, doi 10.1007/s10569-010-9320-4.

* Davies, M.E. and Colvin, T.R. (2000), Lunar coordinates in the regions of the Apollo landers. JGR 105(E8), pp. 20,277 - 20,280.

* Folkner, W. M., Williams, J. G., and Boggs, D. H. (2008), The Planetary and Lunar Ephemeris DE 421. JPL Memorandum IOM 343R-08-003, 31 March. Url: ftp://ssd.jpl.nasa.gov/pub/eph/planets/ioms/de421.iom.v1.pdf.

* Folkner, W. M., Williams, J. G., and Boggs, D. H. (2009): The Planetary and Lunar Ephemeris DE 421. IPN Progress Report 42-178, August 15. Url: http://ipnpr.jpl.nasa.gov/progress_report/42-178/178C.pdf.

* Greeley, R. and Batson, R.M. (1990), Planetary mapping: Cambridge University Press, pp. 274–275. * LRO Project and LGCWG (2008), A standardized lunar coordinate system for the Lunar Reconnaissance Orbiter and lunar datasets, LRO Project and LGCWG White Paper, version 5 of October 1, Url: http://lunar.gsfc.nasa.gov/library/LunCoordWhitePaper-10-08.pdf.

* Mazarico, E., Rowlands, D.D., Neumann, G.A., Smith, D.E., Torrence, M.H., Lemoine, F.G. and Zuber, M.T. (2012). Orbit determination of the Lunar Reconnaissance Orbiter, Journal of Geodesy, Vol. 86-3, pp. 193-207.

* Neumann, G. A. (2011), Lunar Reconnaissance Orbiter Lunar Orbiter Laser Altimeter Reduced Data Record and Derived Products Software Interface Specification, version 2.42. Url: http://imbrium.mit.edu/DOCUMENT/RDRSIS.PDF

* Smith, D.E., Zuber, M.T., Neumann, G.A., Lemoine, F.G., Mazarico, E., Torrence, M.H., McGarry, J.F., Rowlands, D.D., Head, J.W., III, Duxbury, T.H., Aharonson, O., Lucey, P.G., Robinson, M.S., Barnouin, O.S., Cavanaugh, J.F., Sun, X., Liiva, P., Mao, D., Smith, J.C. and Bartels, A.E. (2010), Initial observations from the Lunar Orbiter Laser Altimeter (LOLA), Geophysical Research Letters, 37, L18204, doi:10.1029/2010GL043751.

* Smith, D.E., Zuber, M.T., Neumann, G.A., Mazarico, E., Head, J.W., III, Torrence, M.H. and the LOLA Science Team (2011), Results from the Lunar Orbiter Laser Altimeter (LOLA): global, high-resolution topographic mapping of the Moon, Lunar Planetary Science Conference XLII, Abstract 2350.

* Tooley, C.R., Houghton, M.B., Saylor, R.S., Peddie, C., Everett, D.F., Baker, C.L. and Safdie, K.N. (2010), Lunar Reconnaissance Orbiter mission and spacecraft design, Space Sci. Rev., 150, pp. 23–62, doi:10.1007/s11214-009-9624-4.

* Wessel, P. and Smith, W.H.F., 1998, New, improved version of Generic Mapping Tools released: Eos, Transactions of the American Geophysical Union, v. 79, no. 47, p. 579.

* Williams, J. G., Boggs, D. H., and Folkner, W. M. (2008), DE421 Lunar Orbit, Physical Librations, and Surface Coordinates. JPL Interoffice Memorandum IOM 335-JW,DB,WF-20080314-001, 14 March. Url: ftp://ssd.jpl.nasa.gov/pub/eph/planets/ioms/de421_moon_coord_iom.pdf.

Publisher

LOLA Science Team

Publication Date

11 March 2014

Author

LOLA Science Team

Originator

Goddard Space Flight Center

Group

PDS

Added to Astropedia

17 January 2014

Modified

15 May 2017

General

Purpose

To create a preliminary elevation model for the Moon.

Geospatial Data Presentation Form

Digital Elevation Model, Topographic Map, Remote-sensing Data

Edition

March 11, 2014

Online Linkage

http://planetarymaps.usgs.gov/mosaic/Lunar_LRO_LOLA_Global_LDEM_118m_Mar2014.tif

Native Data Set Environment

ISIS v3

Supplemental Information

http://pds-geosciences.wustl.edu/missions/lro/lola.htm

Keywords

System

Earth

Target

Moon

Theme

Topography, Remote Sensing, Image Processing

Mission

Lunar Reconnaissance Orbiter

Instrument

LOLA

Contact and Distribution

Access Constraints

public domain

Use Constraints

Please cite authors

Data Status and Quality

Time Period of Content Begin

13 July 2009

Time Period of Content End

18 July 2013

Currentness Reference

Ground condition

Progress

In Work

Update Frequency

As needed

Logical Consistency Report

The LOLA data were initially referenced to an internally consistent inertial coordinate system, derived from tracking of the LRO spacecraft. By adopting appropriate values for the orientation of the Moon as defined by the International Astronomical Union (IAU, Archinal and others, 2011), these inertial coordinates were converted into the planet-fixed coordinates (longitude and latitude) used on this map. The coordinate system defined for this product is the mean Earth/polar axis (ME) system. The ME system, sometimes called the mean Earth/rotation axis system, is the method most often used for cartographic products of the past (Davies and Colvin, 2000). Values for the orientation of the Moon were derived from the JPL DE/LE 421 planetary ephemeris (Williams and others, 2008; Folkner and others, 2008, 2009), rotated into the ME system. Longitude increases to the east and latitude is planetocentric as allowed in accordance with current international and NASA standards (Archinal and others, 2011; LRO Project and LGCWG, 2008). The intersection of the lunar equator and prime meridian occurs at what can be called the Moon’s “mean sub-Earth point.” The concept of a lunar “sub-Earth point” derives from the fact that the Moon’s rotation is tidally locked to the Earth. The actual sub-Earth point on the Moon varies slightly due to orbital eccentricity, inclination, and other factors, so a “mean sub-Earth point” is used to define the point on the lunar surface where longitude equals 0°. This point does not coincide with any prominent crater or other lunar surface feature (Archinal and others, 2011; LRO Project and LGCWG, 2008).

Completeness Report

Gaps between tracks of 1–2 km are common, and some gaps of up to 4 km occur near the equator. DEM points located in these gaps in LOLA data were filled by interpolation (Smith and others, 2011). The high and low elevations in the DEM are approximate because of the interpolation process uesd.

Process Description

The LOLA measurements were converted into a digital elevation model (DEM; Neumann and others, 2010) using Generic Mapping Tools software (Wessel and Smith, 1998), with a resolution of 256 pixels per degrees. In projection, the pixels are 118 meters in size at the equator. PRODUCT_CREATION_TIME = 2014-03-11T00:00:00

Horizontal Positional Accuracy Value

20

Horizontal Positional Accuracy Report

Best Effort

Vertical Positional Accuracy Value

1

Vertical Positional Accuracy Report

Best Effort

Entity and Attribute Overview

Elevation in meters

Entity and Attribute Detailed Description

Conversion to local height (meters) is accomplished via the following equation:
Height = (Pixel Value * Scaling Factor)
Conversion to local Radius (meters) is computed as follows:
Radius = (Pixel Value * Scaling factor) + 1737400
where Scaling Factor = 0.5 (as listed in the label as Multiplier)

e.g. conversion using GDAL tools: >gdal_translate -unscale -ot float23 -co bigtiff=if_safer in.cub out_32bit.cub

Elevations were originally computed by subtracting the lunar reference radius of 1737400.0 m (Archinal and others, 2011; LRO Project and LGCWG, 2008) from the surface radius measurements. Thus elevation values are the distance above or below the reference sphere.

Lineage

Source Originator

Planetary Data System Geosciences Node

Source Title

The LOLA Data Node

Source Online Linkage

http://pds-geosciences.wustl.edu/missions/lro/lola.htm

Type of Source Media

Online

Attribute Accuracy Report

Best Effort

Geospatial Information

Minimum Latitude

-90

Maximum Latitude

90

Minimum Longitude

-180

Maximum Longitude

180

Direct Spatial Reference Method

Raster

Object Type

Pixel

Lines (pixels)

46080

Samples (pixels)

92160

Bit Type

16

Radius A

1737400

Radius C

1737400

Bands

1

Pixel Resolution (meters/pixel)

118.4505876

Scale (pixels/degree)

256

Horizontal Coordinate System Units

Meters

Map Projection Name

Simple Cylindrical

Latitude Type

Planetocentric

Longitude Direction

Positive East

Longitude Domain

-180 to 180