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The High Resolution Imaging Science Experiment (HiRISE) is a telescope working in orbit in the visible wavelengths and producing high resolution images resolving surface details down to 1-meter size (0.25 to 1.3 m/px). The images enable to study for instance the martian geomorphology but also seasonal surface changes.

Contents[+]
  1. Data description
  2. Processing HIRISE data[+]
    1. HiRISE Imagery
    2. Digital Elevation Model[+]
      1. MarsSI DEM
      2. HiRISE team DEM
  3. References[+]
    1. [+]
      1. HiRISE team DEM
  4. References

Data description

The HiRISE camera has 3 different color filtered CCDs: red (“RED”) from 570-830 nm, blue-green (“BG”) less than 580 nm and near-infrared (“IR”) greater than 790 nm. The high-resolution color images enable to distinguish the composition and albedo heterogeneities directly correlated to the geomorphology, complementary to the mineralogic results from the CRISM, HRSC, OMEGA and THEMIS instruments. The RED detectors provide a wide image used for geomorphologic analysis and for stereoanalysis, while the additional detectors are used to create false-color imaging of the central of the swath only (20% of the RED swath width).

Data file description:

  • PSP_005000_1000_RED.JP2 (grayscale mosaic of all RED-filter channels)
  • PSP_005000_1000_COLOR.JP2 (IR, RED, BG 3-color product over center 20% of the RED swath width)

Each JP2 image also has a PDS label (.lbl) providing useful information about the observation such as map projection and viewing information.

Processing HIRISE data

HiRISE Imagery

The pipeline for the topographic mapping derived from HiRISE images uses both the USGS ISIS system (the ISIS 3 system).

From the “Maps” tab, zoom-in on your region of interest, you can display the THEMIS mosaic for more precision, and then display the HiRISE layer. You get all HiRISE footprints that appear in blue. The footprints are regularly updated to take into account new data. You can use the “Select” button to choose the footprint you desire. You can choose several footprints by clicking several footprints, or by dragging your mouse to select adjacent footprints. You can also use the “Search” button for more options.

wiki/HiRISE/view_hirise_layer.png

To add your desired footprints to your cart click on “Add” in the “Cart” window, and go to the “Workspace” tab. Your HiRISE image appears in the window “Data to process”. If not, you may already have processed it yourself, or someone else may have processed it, then it may already be in the “Data processed” window. If the image has not been processed, you will have to go through several steps:

  1. Download the HiRISE EDR image (rawdata) to the MarsSI server by clicking on the EDR image and the “Process” button in the “Data to process” window. This will take a few minutes.
  2. When the first step is done, you can create a calibrated RDR image: click on the proposed RDR image in the “Data to process” window and on the “Process” button. This will take another few minutes, depending on the length of the observation.
  3. Project the image by processing the proposed MRDR image in the “Data to process” window. This will take more time than the previous processes, another few minutes.

When these different steps are done, the MRDR image is waiting for you in the “Data processed” window and you can copy it to your SFTP partition.

Digital Elevation Model

MarsSI DEM

In order to realize a HiRISE DEM, you must have proceeded through all the HiRISE imagery processing steps, described in the previous section.

The HiRISE DTM images created by MarsSI are generated using the NASA AMES Stereo Pipeline (http://ti.arc.nasa.gov/tech/asr/intelligent-robotics/ngt/stereo/).

From the “Maps” tab, zoom-in on your region of interest, you can display the THEMIS mosaic for more precision, and then display the HiRISE stereo layer. You get all areas where MarsSI proposes to compute a HiRISE DEM, appearing in light blue. The footprints are regularly updated to take into account new data. You can use for example the select button to choose the footprint you desire.

wiki/HiRISE/view_hirise_stereo_layer.png

To add your desired footprints to your cart click on “Add” in the “Cart” window: you can notice in the “Cart” window that three data were added, the two overlapping EDR images that will be used, and the EDTM file that will be computed. Then go to the “Workspace” tab.

The EDTM footprints have been created automatically based on the percentage of intersection and the difference in emission angle between the two EDR images. Please be advised that EDTM footprints mean only possible DTMs: a viewing validation of the EDR images should be performed from the PDS’s link available in the footprint attribute. Atmospheric clouds for example can prevent the DTM calculation.

Your images and DTM appear in the window “Data to process”. If not, you may already have processed it yourself, or someone else may have processed it, then it may already be in the “Data processed” window. If the images have not been processed, you will have to go through several steps:

  1. Download the HiRISE EDR image (raw data) to the MarsSI server and create a calibrated RDR image as described previously.
  2. Create the DTM by processing the proposed EDTM data in the “Data to process” window which may take few hours, depending on the length of the overlapping images.
  3. Process the proposed ALEDTM data in the “Data to process” window to align the DEM to the MOLA data. This last step should only take few minutes.

When these different steps are done, the ALEDTM is waiting for you in the “Data processed” window and you can copy it to your personal data directory.

Additional information about AMES Stereo Pipeline products can be found in: http://byss.ndc.nasa.gov/stereopipeline/binaries/asp_book-2.5.0.pdf

HiRISE team DEM

This dataset was created using the commercial stereogrammetric software SOCET SET and tuned by hand by the HiRISE team. The DTMs have a 1-meter spatial resolution and 25 cm vertical precision. For more details about the process used to create HiRISE DTMs, see Kirk, R.L. et al. (2008).

wiki/HiRISE/view_hirise_team_stereo_layer.png

References

  • HiRISE instrument and data website: http://hirise.lpl.arizona.edu
  • HiRISE DTM creation explanation: http://www.uahirise.org/dtm/about.php
  • HiRISE instrument description paper: McEwen, A. et al. (2007). J. Geophys. Res., 112, E05S02, doi:10.1029/2005JE002605.
  • HiRISE DTM description paper: Kirk, R.L. et al. (2008). J. Geophys. Res., 113, E00A24, doi:10.1029/2007JE003000.Additional information about AMES Stereo Pipeline products can be found in:

http://byss.ndc.nasa.gov/stereopipeline/binaries/asp_book-2.5.0.pdf

HiRISE team DEM

This dataset was created using the commercial stereogrammetric software SOCET SET and tuned by hand by the HiRISE team. The DTMs have a 1-meter spatial resolution and 25 cm vertical precision. For more details about the process used to create HiRISE DTMs, see Kirk, R.L. et al. (2008).

wiki/HiRISE/view_hirise_team_stereo_layer.png

References