# Presentation: 867651

## Operation of MRO's High Resolution Imaging Science Experiment (HiRISE):

**Operation of MRO's High Resolution Imaging Science Experiment (HiRISE):**
**Maximizing Science Participation**
- E. Eliason1, C. J. Hansen2, A. McEwen3, W.A. Delamere4, N. Bridges2, J. Grant5, V. Gulick6, K. Herkenhoff1, L. Keszthelyi1, R. Kirk1, M. Mellon7, P. Smith3, S. Squyres8, N. Thomas9, and C. Weitz10.
- 1USGS, 2JPL, 3LPL, University of Arizona, 4Ball Aerospace and Tech. Corp., 5CEPS, Smithsonian Ins., 6NASA Ames/SETI,  7University of Colorado, 8Cornell University, 9University of Bern, Switzerland, 10PSI/NASA

**Introduction:**

**Selection of Targets:**

**MRO Begins Mapping in November 2006:** The Mars Reconnaissance Orbiter (MRO) will arrive at Mars in March 2006. Following an orbital aerobraking and transition phase the mission will begin its Primary Science Phase (PSP) in November 2006.
**Two-Year Mapping Phase**: PSP lasts for almost 2 Earth years followed by a 2-year relay phase in which observations by MRO are expected to continue.
**Thousands of HiRISE Images Acquired:** We expect to acquire ~10,000 images with the MRO High Resolution imaging Science Experiment (HiRISE) over the course of MRO’s two earth-year mission. HiRISE can acquire images with ground sampling dimension of as little as 30 cm (from 300 km spacecraft altitude), in up to 3 colors, and many targets will be re-imaged for stereo [1,2] (see Figure 1).
**HiRISE Observes ~1% of Mars:** With such high spatial resolution, the coverage of Mars will be limited in spite of the relatively high data rate of MRO (~10x greater than Odyssey). We expect to observe ~1% of Mars at ~1 m/pixel or better, ~0.1% at full resolution, and ~0.05% in color or in stereo.  Therefore, the placement of each HiRISE image must be carefully considered to maximize scientific return.
**Every Observation Carefully Considered:** We believe every observation should result from a mini research project based on preexisting datasets. During operations, we will need a large database of carefully researched suggested locations from which to select our targets.
**Involvement by Mars Science Community:** The HiRISE team is dedicated to involving the broad Mars community in creating this database to the fullest degree practical. The philosophy of the team and the design of the ground data system are geared to enabling community involvement. A key aspect is to make the image data available to the planetary community for science analysis as quickly as possible to encourage feedback and new ideas for targets.

**HiRISE Co-Is Take Responsibility for Science Themes: **In order to be sure the best possible targets are imaged, the HiRISE Co-investigators (Co-I’s) will each take responsibility for a particular science theme (e.g. volcanism, fluvial processes, polar geology, etc). For each theme, key issues will be identified along with the particular targets that could advance our understanding of Mars if imaged at high resolution.

- Figure 1 – HiRISE acquires panchromatic and color imaging with 30 cm ground sampling at 300 km spacecraft altitude

**HiRISE Co-Is Evaluate Suggested Targets from Science Community:** The CO-I in charge of a given theme will evaluate and prioritize suggested targets from the science community then advocate these targets through the sequence planning process. Workshops in conjunction with large science meetings will be held to facilitate science community input.
**Science Community Invited to Propose Image Investigations:** The community will be invited to propose image investigations that address our understanding of processes on Mars.  The web portal to the database of potential HiRISE targets (HiWEB, see Figure 2) will be open to the community for their direct input.  Potential landing site targets will be supplied by Mars Exploration Program representatives to the project, also via a process that solicits input from the science community.

**Operations Concept:**

**Co-Is Monitor Uplink Process:** The operational concept features scientists monitoring the entire uplink planning process. Co-I’s will make sure the big-picture view of what we’re trying to learn about Mars is present throughout the decision making process including prioritization of targets, resource allocation, and optimization of the camera operating modes.
**HiPLAN Used to Develop Command Sequences:** The Co-I’s will be assisted by operations staff knowledgeable in the software tools used to plan command sequences, and camera and spacecraft limitations. Our targeting tool (HiPLAN, Figure 2)  will be based on the JMARS tool developed by Mars Odyssey’s THEMIS team to target THEMIS images.

**TAG Team Plans Coordinated Observing:** The MRO spacecraft is nominally pointed nadir, but may be maneuvered up to 30 degrees off-nadir to acquire a target. The Context Imager (CTX) and CRISM instruments will also have desired targets. The Target Acquisition group (TAG) made up of the MRO Project Scientist, scientists from each team, and representatives from the Mars Exploration Program, will plan timelines of all off-nadir images approximately 4 weeks ahead of their acquisition (see Figure 3). Updates to the ephemeris will be used to adjust the actual off-nadir angle and timing.  Co-I’s will take turns participating in the TAG process to advocate investigations and to work with CTX and CRISM on joint investigations.

**Nadir Targets Planned ~1 Week Before Acquisition**: Nadir targets of opportunity will be planned ~1 week before acquisition.  These are selected by the rotating Co-I from the data base of suggested observations.   The camera has a number of configuration parameters [2] which will be set by the Co-I based on the science requirements associated with a given image, the atmospheric opacity of Mars, and the data volume available.

**HiRISE Operations Center Located at University of Arizona:** In the same distributed operations architecture used by Mars Global Surveyor and Odyssey, MRO science teams will operate their instruments from their home institutions.  The Operations Center (HiROC, see Figure 4), located at the University of Arizona in Tucson, will be the hub of HiRISE uplink planning and downlink data processing. Requests for targets come in from the Co-I’s, outside scientists, scientists from other MRO instrument teams, and the general public (filtered through NASA Quest, [3]) via HiWEB and are stored in the “HiCAT” target data base.  The actual orbits on which targets will be imaged are planned using HiPLAN.  A final piece of software, “HiCOMMAND,” is used to format instrument commands for uplink to the spacecraft.

**ISIS Image Processing:** The Integrated Software for Imagers and Spectrometers (ISIS) [6] will be used for image processing and analysis. ISIS offers image analysis, cartographic processing and mosaicking capabilities, control to geodetic networks, and data archive preparation tools. The HiRISE processing capabilities added to ISIS will be freely available to the science community through periodic distribution of ISIS, allowing scientists to perform specialized cartographic and image processing on HiRISE data at their home institutions.

**Data Processing:**

**Timely Access to HiRISE Images:** The goal of the data processing system is to provide timely access to the imaging and to keep up with the high volume (9.1 Tb)  of instrument data acquired during PSP. To meet this goal HiROC will employ  automated event-driven methods  for downloading and processing HiRISE instrument science data. The data processing begins when the downlink organizer, “HiDOG” (Figure 1), retrieves instrument data from the MRO operations center at JPL and delivers it to HiCAT. “HiPROC,” the automated processing engine, will decompress the data if compressed by the onboard FELICS compressor [4], perform radiometric and geometric processing, and format data products according to PDS standards [5]. Data will be made available to MRO Project and community scientists through HiWEB
**Radiometric Correction:** The radiometric calibration process normalizes for global camera operational modes, corrects for the variable sensitivity across the CCD detector arrays, and converts pixel values to radiometric units.  The result is an "ideal" image where pixel values are proportional to scene brightness (see Figure 5).

**Geometric Processing:** The geometric processing applied to HiRISE imaging will depend on the instrument's pixel binning modes [2] used in an observation. Image observations with no pixel binning, offering the highest resolution capability of the instrument, are vulnerable to the effects of spacecraft jitter requiring an analysis (see below) to improve the instrument pointing history and  model the point-spread function (PSF) (see Figure 5).

**References:**

- [1] McEwen, A. this conference. [2] Delamere, W. A. this conference. [3] Gulick, V.  this conference. [4] Howard, P.G. and J.S. Vitter (1993) *Proc. Data Compression Conference*, J.A. Storer & M. Cohn, eds., Snowbird, Utah, 351-360. [5] Planetary Data System Standards Reference (2002) JPL Document D-7669. [6] Eliason, E.M. (1997) LPS XXVIII, 331-332. [7] McMahon, S.K. (1996) *Planetary and Space Sciences, *44,1, 3-11.

**Standard Data Products:** The standard data products produced by the team will be the EDR and binned RDR products (panchromatic and color) and will be made available to the general science community within weeks of data acquisition through HiWEB's data distribution capability and periodically delivered to NASA's permanent archiving institution. Table 1 summarizes the products generated by the HiRISE team.

**HiRISE Products Delivered to the Permanent Archive Facility:** The MRO Project requires instrument teams to maintain an updated dataset of the best version of data until meaningful changes in data calibration no longer occur and support the timely processing and distribution of data including their final deposition to the permanent archive facility at the Planetary Data System (PDS) [7]. The distribution of data products to the PDS will be coordinated through the Project’s Data Archive Working Group (DARWG) made up of representatives from the MRO project, science payload teams, and the PDS. The DARWG provides the oversight for data product preparation, acceptance, validation and delivery to the archive facility.

| 
Table 1 - HiRISE Data Products
 |  |
| --- | --- |
| EDR | “Raw” data from a single CCD, up to 14 EDR products for each observation. First delivery to PDS is PSP + 6 months |
| Binned Panchromatic RDR | RDR products are radiometrically corrected and resampled to a standard map projection. Data acquired at full resolution will be binned 2x2 on the ground; data acquired with 2x2 or greater binning will be processed at binned scale. First delivery to PDS is PSP + 12 months |
| Binned Color RDR | Data acquired from NIR and Blue-Green CCDs (in addition to panchromatic RED) will be assembled into color images at the scale of NIR or Blue-green binning (typically greater than Red binning). First delivery to PDS is PSP + 12 months |
| Full-Resolution Panchromatic RDR | Same as binned panchromatic RDR products except resampling has preserved the full resolution through PSF deconvolution and high-frequency pointing characterization by spacecraft jitter analysis. Delivered to PDS EOM+6 months |
| Full-Resolution merged color RDR | Merge binned NIR and Blue-Green data with Red data scaled to full resolution of observation. Delivered to PDS EOM+6 months. |
| 2x2 Binned Stereo RDR | Reprocessed imaging with PSF deconvolution and high-frequency pointing characterization by jitter analysis. Delivered to PDS EOM+6 months. |
| Digital Elevation Models  | Surface elevation models derived from digital photogrammetic stereo analysis. A few dozen stereo models will be developed by the team. Delivered to PDS EOM+6 months. |

**Data Products:**

**Spacecraft Jitter Problematic for HiRISE****:** With the instrument's 1 microradian instantaneous field-of-view, the full-resolution (unbinned) imaging is sensitive to spacecraft jitter resulting from the spacecraft's moving parts. High-frequency spacecraft jitter broadens the PSF and reduces spatial resolution.  Lower frequency spacecraft jitter distorts the image geometry. We have been exploring methods for internally characterizing the jitter effects on imaging.
**Correction for Spacecraft Jitter:** The CCD layout on the detector array (see Figure 5) allows for 48-pixel overlap among adjacent detectors in the orbit crosstrack direction. In the downtrack direction the CCDs are offset by different amounts ranging from 608 (the minimum offset) to 640 lines. Ground features in the image data can be correlated between the 48-pixel overlapping pairs or triplets of CCDs to characterize the divergence between actual and predicted spacecraft motion. Based on the spacecraft jitter analysis a more accurate model of the instrument pointing history can be constructed to improve the geometric processing. The high-frequency component of the jitter analysis is used to construct a varying PSF model throughout an observation. The PSF model is used to perform image sharpening through an adaptive PSF deconvolution.