Working with Mars Reconnaissance Orbiter HiRISE Data

From Isis Workshop

Revision as of 22:35, 14 February 2011

About MRO HiRISE

The Mars Reconnaissance Orbiter Mission

Instrument Overview

HiRISE Instrument A comparision between the resolution of a camera aboard Mars Gloabal Surveyor and the HiRISE camera on Mars Reconnaissance Orbiter. Credit: NASA/JPL

HiRISE has acquired more than 20,000 images of the martian surface in unprecedented detail.

HiRISE operates in visible wavelengths with a telescope that will produce images at resolutions never before possible in planetary exploration. These high resolution images will enable scientists to resolve 1-meter (about 3-foot) sized objects on Mars and to study the morphology (surface structure) in a much more comprehensive manner than ever before.

From an altitude of approximately 300 kilometers above Mars, HiRISE will return surface images comprised of pixels representing 30 centimeters of the martian surface.

These high-resolution images provide unprecedented views of layered materials, gullies, channels, and other science targets, as well as possible future landing sites.

Technical Details

HiRISE Observation: This image is one half (vertically) of a HiRISE observation scaled down to approximately 1/50th of its original resolution. It is of a small area inside Eberswalde crater in Margaritifer Sinus. Taken on November 8, 2006, the image is a composite of all 10 red detectors and the 2 blue-green detectors.

Full Resolution Subarea: This is a full resolution sub-area of the image on the right (indicated by the red outline). One pixel represents 25.6 cm on the surface of Mars.

This telescopic camera has a primary mirror diameter of 50 centimeters and a field of view of 1.15°. At its focal plane, the instrument holds an array of 14 electronic detectors, each covered by a filter in one of three wavelength bands: 400 to 600 nanometers (blue-green), 550 to 850 nanometers (red), or 800 to 1000 nanometers (near-infrared). Ten red detectors are positioned in a line totaling 20,028 pixels across to cover the whole width of the field of view. Typical red images are 20,000 pixels wide by 40,000 lines high. Two each of the blue-green and near-infrared detectors lie across the central 20% of the field. Pixel size in images taken from an altitude of 300 kilometers will be 30 centimeters across, about a factor of two better than the highest-resolution down-track imaging possible from any earlier Mars orbiter and a factor of five better than any extended imaging to date. As a rule of thumb, at least three pixels are needed to show the shape of a feature, so the smallest resolvable features in the images will be about a meter across for an object with reasonable contrast to its surroundings. The instrument uses a technology called time delay integration to accomplish a high signal-to-noise ratio for unprecedented image quality.

The Principal Investigator (lead scientist) for HiRISE is Alfred McEwen from the Lunar and Planetary Laboratory at the University of Arizona.

References & Related Resources

• HiRISE instrument description
• HiRISE instrument technical description (PDF)
• HiRISE mission web site
• en.wikipedia.org/wiki/HiRISE
• Mars Reconnaissance Orbiter mission web site

Cartographic Processing HiRISE Data

Level 0 Processing

1. Data Acquisition
2. Ingestion
3. SPICE
4. Raw Camera Geometry

Level 1 Processing

1. Radiometric Calibration
2. Channel Stitching
3. Noise Removal

Level 2 Processing

1. Overview
2. Map Projection
3. Tone Match
4. Mosaic

Batch Processing

The ingestion, SPICE initialization, calibration, merging, and normalization must be run for each channel image. This would be incredibly tedious to run each application for every file! Luckily, batch processing is easy to do in Isis3. Using the Isis -batchlist command line option[[1]], a set of CCD images for a single observation can easily be processed through level 1 processing.

The commands shown below create file lists to use as inputs to the applications and run those applications using the batchlist option:

1. create a single column list of images without the file extension
ls *.IMG | sed s/.IMG// > cube.lis

2. run hi2isis on the list of files, adding the input/output extensions in the command line
hi2isis from=\$1.IMG to=\$1.cub -batchlist=cube.lis

3. apply spiceinit to the hi2isis output cube files
spiceinit from=\$1.cub -batchlist=cube.lis

4. apply hical with the appropriate input/output file extensions
hical from=\$1.cub to=\$1.cal.cub -batchlist=cube.lis

5. create a list of one of the channels without file extensions
ls *_0.IMG | sed s/_0.IMG// > cube2.lis

6. stitch together the channels specifying each appropriate extension in the command line
histitch from1=\$1_0 from2=\$1_1 to=\$1 -batchlist=cube2.lis

7. normalize, tone-match across the channels (if necessary)
cubenorm from=\$1 to=\$1.norm.cub -batch=cube2.lis

Related Isis Applications & Documentation

See the following Isis documentation for information about the applications you will need to use to perform this procedure:

• Isis Command Line Usage: how to run Isis programs on the command line
• hi2isis: converts a HiRISE EDR to Isis cube format
• spiceinit: adds SPICE information to the input cube
• hical: radiometrically calibrates HiRISE channel images
• histitch: combines two HiRISE channel images to form a single CCD image
• cubenorm: normalizes values in a image

Exporting Isis Data

Overview for exporting ISIS3 data

Exporting large HiRISE images

HiRISE mosaics are very large and our export application isis2std does not handle large PNG or JPEG images. You will need to decrease the size of the image to export by either cropping or reducing.

Related Isis Applications

See the following Isis documentation for information about the applications you will need to use to perform this procedure:

• reduce: scale down a cube
• crop: pull a region out of a cube

Create a HiRISE Anaglyph

See: HiRISE Anaglyphs