Working_with_Lunar_Reconnaissance_Orbiter_(LRO)_Data

Working with Lunar Reconnaissance Orbiter (LRO) Data ¶

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LRO ¶

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• LRO
  • • Brief Mission Summary
    • Science Goals
    • Science Instruments
    • Data Processing with ISIS
    • • LRO Narrow Angle Camera (NAC)
    • • LRO Wide Angle Camera (WAC)
    • • MiniRF

  • References & Related Resources

    • Planetary Data System (PDS) Information and Data Search Tools

Brief Mission Summary ¶

The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit. Data collected by LRO have been described as essential for planning NASA's future human and robotic missions to the Moon. Its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies.

Launched on June 18, 2009, in conjunction with the Lunar Crater Observation and Sensing Satellite (LCROSS), as the vanguard of NASA's Lunar Precursor Robotic Program, LRO was the first United States mission to the Moon in over ten years. LRO and LCROSS were launched as part of the United States's Vision for Space Exploration program.

See https://en.wikipedia.org/wiki/Lunar_Reconnaissance_Orbiter for further information.

Science Goals ¶

Areas of investigation include selenodetic global topography; the lunar polar regions, including possible water ice deposits and the lighting environment; characterization of deep space radiation in lunar orbit; and high-resolution mapping, at a maximum resolution of 50 cm/pixel (20 in/pixel), to assist in the selection and characterization of future landing sites.

Science Instruments ¶

See https://en.wikipedia.org/wiki/Lunar_Reconnaissance_Orbiter#Payload.

Data Processing with ISIS ¶

LRO Narrow Angle Camera (NAC) ¶

LRO NAC consists of two cameras, with both acquiring image data at the same time, denoted with L and R.

What follows is an example of processing the experimental data records (EDR) for images M104318871LE and M104318871RE.

Visit http://wms.lroc.asu.edu/lroc/search and search for these. Once you have the full URL, they can be downloaded with wget. This will result in two files, named M104318871LE.img and M104318871RE.img.

We convert each .img file to an ISIS .cub camera image, initialize the SPICE kernels, and perform radiometric calibration and echo correction. Here are the steps, illustrated on the first image:

lronac2isis from = M104318871LE.IMG     to = M104318871LE.cub
spiceinit   from = M104318871LE.cub
lronaccal   from = M104318871LE.cub     to = M104318871LE.cal.cub
lronacecho  from = M104318871LE.cal.cub to = M104318871LE.cal.echo.cub

The obtained images can be inspected with qview.

LRO Wide Angle Camera (WAC) ¶

We will focus on the monochromatic images for this sensor. Visit:

https://ode.rsl.wustl.edu/moon/indexproductsearch.aspx

Find the Lunar Reconnaissance Orbiter -> Experiment Data Record Wide Angle Camera - Mono (EDRWAM) option.

Search either based on a longitude-latitude window, or near a notable feature, such as a named crater. Here are a couple of images having the Tycho crater:

http://pds.lroc.asu.edu/data/LRO-L-LROC-2-EDR-V1.0/LROLRC_0002/DATA/MAP/2010035/WAC/M119923055ME.IMG
http://pds.lroc.asu.edu/data/LRO-L-LROC-2-EDR-V1.0/LROLRC_0002/DATA/MAP/2010035/WAC/M119929852ME.IMG

Fetch these with wget. For a dataset called image.IMG, do:

lrowac2isis from = image.IMG to = image.cub

This will create so-called even and odd datasets, with names like image.vis.even.cub and image.vis.odd.cub.

Run spiceinit on them to set up the SPICE kernels:

spiceinit from = image.vis.even.cub
spiceinit from = image.vis.odd.cub

followed by lrowaccal to adjust the image intensity:

lrowaccal from = image.vis.even.cub to = image.vis.even.cal.cub
lrowaccal from = image.vis.odd.cub  to = image.vis.odd.cal.cub

If these are inspected, such as with qview, it can be seen that instead of a single contiguous image we have a set of narrow horizontal bands, with some bands in the even and some in the odd cub file. The pixel rows in each band may also be recorded in reverse.

The only way to fix these artifacts currently is to mapprojected these images and fuse them. This happens as:

cam2map from = image.vis.even.cal.cub to = image.vis.even.cal.map.cub
cam2map from = image.vis.odd.cal.cub  to = image.vis.odd.cal.map.cub  \
  map = image.vis.even.cal.map.cub matchmap = true

Note how in the second cam2map call we used the map and matchmap arguments. This is to ensure that both of these output images have the same resolution and projection. In particular, if more datasets are present, it is suggested for all of them to use the same previously created .cub file as a map reference. That makes terrain creation with photogrammetry work more reliably.

The fusion happens as:

ls image.vis.even.cal.map.cub image.vis.odd.cal.map.cub  > image.txt
noseam fromlist = image.txt to = image.noseam.cub SAMPLES=73 LINES=73

The obtained file image.noseam.cub may still have some small artifacts but should be overall reasonably good.

MiniRF ¶

See MiniRF - Miniature Radio Frequency instrument

References & Related Resources ¶

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Planetary Data System (PDS) Information and Data Search Tools ¶

• PDS Geosciences Node, Lead Node for LRO: http://geo.pds.nasa.gov/missions/lro/default.htm
  • Lunar Orbital Data Explorer: http://ode.rsl.wustl.edu/moon/
• PDS Imaging Node:
  • Data Release Calendar: http://pds-imaging.jpl.nasa.gov/schedules/lro_release.html
  • LRO Mission: http://pds-imaging.jpl.nasa.gov/portal/lro_mission.html
  • Photojournal: http://photojournal.jpl.nasa.gov/mission/LRO
  • Planetary Image Locator Tool (PILOT): http://pilot.wr.usgs.gov/index.php?view=map&target=moon
• PDS Engineering Node:
  • Global data search engine: http://pds.nasa.gov/
• PDS Navigation and Ancillary Information Node:
  • Spice Kernels: https://naif.jpl.nasa.gov/pub/naif/pds/data/lro-l-spice-6-v1.0/
  • Toolkit: ftp://naif.jpl.nasa.gov/pub/naif/toolkit/