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Possible to use LOLA instrument data to generate heightmap?


aviator2005
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I'm completely new to this field and trying to engage in some self-study through a personal project.

 

I'm trying to determine if it is possible to generate a heightmap using data captured by the LOLA instrumentation on the LRO mission that can be imported to a 3D modeling tool to generate a terrain mesh mirroring the lunar surface.

 

If it is possible, could someone please point me to subject areas I need to be reading up on to be able to understand the data/process better?

 

If it is actually possible and I'm able to generate a terrain mesh I'd like to see if its possible to apply high resolution imagery captured as a texture to the created mesh. All the while, keeping the entire model scaled in the sense that size is represented accurately and the texture is overlayed on the mesh so that rocks/craters are all positioned correctly.

 

Any insight would be incredibly helpful.

 

 

Thank you!

 

 

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Hi,

 

The simple answer is yes.  LOLA provides two data sets that can be used for creating height maps.  And then you can overlay images from sources such as the Lunar Reconnassance Orbiter Camera (LROC) or Clementine's Hi-Res Camera.  Note, getting the terrain height map can be pretty straight forward but getting the overlay images can be challenging.  It makes it easier if you work with tools that understand map-projections such as ESRI's ArcGIS, ENVI, QGIS, etc.  And if you are going to work with individual LROC CDR images, you may want to get familier with USGS's ISIS tool kit which will allow you to map project individual LROC CDR images.

 

First, you should understand the LOLA instrument and data products.  You can start at our Orbital Data Explorer (ODE) LOLA page.  ODE is a web-based tool for finding and downloading various PDS datasets including LOLA.  Take a look at the LOLA page at http://ode.rsl.wustl.edu/moon/pagehelp/quickstartguide/index.html?lola.htm .  This describes the various LOLA datasets.  Then take a look at the LOLA Software Interface Specification (SIS) at http://imbrium.mit.edu/DOCUMENT/RDRSIS.PDF .  This will give you details on the instrument and data products.  I strongly urge you to review the SIS prior to working with the data products.

 

There are two LOLA data sets that might meet your needs.  Selecting between the two depends on your problem - the size of the area you want to display, the precision, and the tools you use.  The first are the Gridded Data Records (GDRs).  There are several types of GDRs including terrain shape maps, surface roughness maps, and slope maps.  You would be primarily interested in the terrain shape maps, i.e. pre-built terrain height maps.  There are several maps based on area of interest, map resolution, and map projection. 

 

You can get the terrain shape maps by:

1) Open the Lunar Orbital Data Explorer at http://ode.rsl.wustl.edu/moon/index.aspx

2) Select the Data Product Search Tab

3) Open the "Select One or More Desired Data Sets" bar

4) Scroll down and check the box next to LRO LOLA GDRDEM product type

5) (optional) Scroll down and open the "Select by Product Location" and enter either a lunar feature or a lat/lon bounding box

6) Select the "View Results in Table" button

7) By clicking on any product, you can get the details

8) From here you can download the files directly or add them to a cart to download several at once.

 

You can also get the terrain shape maps by using the map:

1) Open the Lunar Orbital Data Explorer at http://ode.rsl.wustl.edu/moon/index.aspx

2) Select the Map Search Tab

3) Zoom to your area of interest by selecting the Zoom tool - click and hold over the map over your area of interest

4) Select the LRO LOLA GDRDEM lay from the list of layers on the left

5) Select the "Select Products By Area" tool from the tools at the top of the map

6) Click and drag over the area of interest

7) LOLA GDRDEM products that cover the area will show up under the "View Selected Results" tab located above the layers list on the left.

8) Selecting a sepecif GDRDEM will show specifics about the product.  You can download the files directly or add them to a cart to download several at a time.

 

Refer to the LOLA SIS to help you select the products in the correct projection and scale that meets your needs.  LOLA GDRDEMS come in either PDS format or JPEG2000 format.  Which one depends on the tools you plan to use although most will use the JP2000 format.

 

If the GDRDEMs are not of high enough resolution for your needs, you can go directly to the individual LOLA altimetry shots.  These form an irregular grid and are suited for building TINs or generating your own gridded terrain height map.  You can get the individual shots using ODE's LOLA RDR Query tool under the tools tab.  Note, there are over 5,000,000,000 individual shots so the area of study should be very small.

 

Using either the GDRs or RDRs to generate your height map depends on the tools you are planning to use.  Many users use tools such as ArcGIS, GDAL, or QGIS.

 

Once you have the terrain height map, you can then overlay lunar images.  For large scale overlays, something like LROC's wide-angle camera mosiac works well.  For smaller areas, you can work with individual LROC images.  Note, these images may not be map-projected and take more work to line them up with LOLA terrain data.  Again, you should review the LROC documentation at http://ode.rsl.wustl.edu/moon/pagehelp/quickstartguide/index.html?lroc.htm for LROC.  Another possible source of overlay images is Clementine or Lunar Orbiter.  Both are available via ODE.

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