LROC Special Data Record NAC Digital Elevation Model Generated Using ISIS and ASP (ASPDTM)

ASPDTM – Special Data Record NAC Digital Elevation Model Generated Using ISIS and ASP

Instrument: Lunar Reconnaissance Orbiter Camera

PDS3 Data Set ID: LRO-L-LROC-5-RDR-V1.0 DOI: 10.17189/1520341 Citations of DOI: 10.17189/1520341

PDS4 Bundle: urn:nasa:pds:lro-l-lroc-5-rdr DOI: 10.17189/a6a1-mw73 Citations of DOI: 10.17189/a6a1-mw73

For more information about LROC Special products, see the RDR Product SIS.

For more information about the PDS3 volume, see the LROC Archive Volume SIS.

The Lunar Reconnaissance Orbiter Camera (LROC) Special Data Record ASPDTM is Digital Elevation Models (DEMs) from LRO Narrow Angle Camera (NAC) stereo imagery generated by an automated processing pipeline using ISIS software and the Ames Stereo Pipeline (ASP; Beyer et al. 2018). The pipeline produces a variety of products, including:

- Digital Elevation Model (DEM): GeoTIFF files representing elevation data in meters relative to datum.

- Slope Map: GeoTIFF file representing elevation slopes in degrees.

- Good Pixel Map: GeoTIFF files indicating valid pixels in processed images.

- Hillshade Map: GeoTIFF files generated to enhance the visual relief of terrain.

- Colored Hillshade Map: Enhanced hillshade maps with color overlays for improved interpretability.

- Orthomosaics: Ortho-images using the accompanied DEM for map projection in image resolution. There is one ortho-image for the left and one for the right stereo image.

- Readme: The readme file contains description of the DEM, precision and accuracy information, description of known artifacts, naming convention, and related products.

 

The processing pipeline comprises the following major stages:

1. Data Selection and Ingestion

- Stereo image pairs are selected based on overlapping conditions and temporal proximity (within 10 LRO orbit periods).

- A MATLAB script filters and records these pairs in a text file to prevent duplicate processing.

2. Preprocessing

- Raw NAC images are calibrated and map-projected using USGS ISIS (versions 3.5.2 and 5.0.0; Becker et al., 2013). The map projection utilizes the 118 m/pixel resolution LRO LOLA DEM (Barker et al., 2016).

- Preprocessing and mosaicking are applied to LRO NAC left and right channels to generate seamless image pairs using NASA ASP script “lronac2mosaic.py”.

3. Stereo Processing (Main Processing)

- The ASP is used to perform bundle adjustment, stereo matching, and DEM generation.

- Processing scripts dynamically read projection parameters and image metadata, adjust map settings, and integrate reference data (e.g., from LRO LOLA) for correcting DEMs.

4. Postprocessing and Archiving

- Final outputs (DEMs, orthoimages, and good pixel maps) are archived.

- Additional derived products such as slope maps, hillshade maps, and colored hillshade maps are generated and archived as well.

 

Known Artifacts:

These are known artifacts present in some, but not all, LROC NAC DEMs. These artifacts may not be present in a particular DEM. Look at the terrain shaded relief and the goodpixel map to detect these before using the DEM!

 

LROC ASPDTM products have the following file names:

NAC_IFPASP_{Latitude}{Hemisphere}{Longitude}_{Counter}_{datatype}.TIF (with detached PDS label)

where:

NAC: Represents the Narrow Angle Camera instrument on the LRO spacecraft.

IFP: Indicates the processing place, which is the Institut für Planetologie, Universität Münster, Germany.

ASP: Denotes that the product was generated using the Ames Stereo Pipeline.

{Latitude}{Hemisphere}{Longitude}{Counter}: Indicates the latitude of the scene center (e.g., 33877S for -33.877° South) and longitude (e.g., 001187 for 1.187° East), both rounded to 1e-3 degrees. If datasets happen to have the same set of coordinates, the counter discriminates individual datasets.

{datatype}: Describes the product type (e.g., DEM, SLOPE, GOODPIXEL, SHADE, CLRSHADE, <NAC Image ID>_ORTHO).

.TIF: All products are saved as GeoTIFF files.

In ODE, ASPDTM products have the following product IDs:

NAC_IFPASP_{Latitude}{Hemisphere}{Longitude}_{Counter}_DEM

 

References

For more information on the methodology of the DEMs, see:

https://zenodo.org/records/15469684/files/ELS_2025_Schmedemann_ea_v2.pdf

RDR SIS: https://pds.lroc.im-ldi.com/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/DOCUMENT/RDRSIS.PDF

Barker, M. K., Mazarico, E., Neumann, G. A., Zuber, M. T., Haruyama, J., & Smith, D. E. (2016). A new lunar digital elevation model from the Lunar Orbiter Laser Altimeter and SELENE Terrain Camera. Icarus, 273, 346-355. https://doi.org/10.1016/j.icarus.2015.07.039

Beyer, Ross A., Oleg Alexandrov, and Scott McMichael. (2018). The Ames Stereo Pipeline: NASA’s open source software for deriving and processing terrain data. Earth and Space Science, 5. DOI:10.1029/2018EA000409.

Becker, K.J. et al. (2013). ISIS Support for NASA Mission Instrument Ground Data Processing Systems, Lunar and Planetary Science Conference, XLIV, abstr. 2829.