We crossed the ten thousand observation mark this week; that’s our total number of observations since arriving at Mars. Roughly 9800 observations are of Mars (of course). Then there’s Phobos, Deimos, Jupiter, and the Earth and Moon (hope you were smiling!).

Over 9400 of these observations have been released to the Planetary Data System as JP2 files (over 9000 of these have color). As of today, 365 observations have been received after the end of the last PDS delivery, and are in the queue for the next one.

A handful of observations have data gaps in critical portions of the raw files (namely, science channel headers), or other severe problems that prevent processing from proceeding. We’re working on improved tools and procedures to alleviate the large amount of manual work to process those images; there’s a very good chance that the usable data can ultimately be recovered and released.

The rest (243 to be exact) are ‘CAL’ or calibration observations, used to verify settings on HiRISE, or obtain data that helps us remove noise and other imaging artifacts in our automated processing. They’re normally taken while on the night side of Mars with ’stim’ lamps on to provide a known, fixed light source.

Take a look at the plot below, which shows the cumulative number of observations received (in salmon) and the cumulative number released (as RDR’s, in mauve) as a function of time.

• The big steps are PDS data releases. The first was six months after beginning the primary operations in November 2006.
• There’s a missing step around December of 2007. That’s because we released a large number of color images, getting caught up with our color processing in lieu of a standard EDR/RDR release.
• The horizontal steps are not completely horizontal. The slope is our rate of weekly featured image releases.
• As noted earlier, just about everything is released, the totals are converging, the lag is 365 observations, or about a month at our current rate.
• The totals are a little less than 10,000; that’s the difference made by the CAL observations and the handful that currently can’t be easily recovered.
• There’s a ‘hump’ of received observations in late 2008, that’s the high data rate period (when Earth and Mars were closest).
• There are a few flat steps where no observations are received. One is the month-long solar conjunction period centered on Nov-Dec 2008, the safe modes of February 2007 and February 2008, etc.

We’re doing about ten observations per day at the moment. During the high data rate period it was nearly double that.

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Yesterday morning we turned the MRO spacecraft around to see our point of origin – the Earth. We took a special calibration image of the Earth and Moon. HiRISE isn’t the first to take a picture of the Earth from Mars, but we’re hoping ours will be even more detailed. We expect the Earth to be about 90 pixels across its diameter, and the Moon about 24 pixels. So it won’t be a big beautiful clear image like you’re used to looking at from our weekly releases, but we should be able to resolve features like continents!

This diagram simulates of what the inner solar system would look like if it were being viewed from above right now. MRO is looking from Mars (orange) towards Earth (purple). You can see from this geometry that we’ll only see the sunlit part of the Earth and Moon as a crescent. They’ll look somewhat less than half full.

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It seems that things are (dare I say?) settling down into a routine here at HiROC. As the cycles progress, we get a little better with each one: software tools are being developed, our procedures are being refined, and we’re becoming more adept and making fewer mistakes (hopefully!). Of course, there are always little interruptions and semi-emergencies that preclude relaxing too much.
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I thought I’d offer a few more words as to what is done with images at HiROC. Validation has been mentioned in the blog, and I’d like to explain a bit more about that. I’ve been involved in writing the primary validation tool, HiVali, and I will be the primary student validator for the next month. (The regular student validators are from out of state, and are going home for the Christmas holidays. I’m from around here, and offered my services to look at pretty pictures from Mars all day;-))

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Well, it’s been a while since we’ve been posting a lot, so I thought I’d just give you guys some kind of an idea as to what we’re doing these days.

The uplink team is constantly looking where to point the camera next. There is a program which is in beta testing now called HiWeb which allows scientists and other people to input suggestions. The Uplink team reviews the suggestions in the database, assigns a priority to each of these suggestions, and then finds when we can point the camera at the part. They also make sure a certain percentage of the upcoming pictures are assigned to look for a Phoenix landing spot, as this is a high priority item at the moment. They are still learning exactly how to best command the camera, and are constantly sharpening their skills.

The downlink team is making sure operations run smoothly at HiROC. They are verifying that the processing has taken place, make sure that the images have been calibrated correctly, that there are no image processing artifacts on the images we are about to release. If there is any artifacts created from processing the image, the source of the problem is identified and fixed, and then the image is reprocessed. While previously we have sent images to the public that had some small processing artifacts during the post-MOI and Transition imaging, we currently are waiting until the images have been completely validated. The downlink team is also taking a quick look at each image that comes down, and making sure there isn’t something unexpected, for example, haze at Mars, lots of saturated pixels, etc. If any such problems are found, they notify the uplink team, to ensure that we don’t have continuing problems. These problems are very rare, but on occasion happen, due to the changing nature of Mars. (more…)

The raw HiRISE image data needs to be cleaned up, and the HiCal pipeline is where this work is done. Now that the raw image data has been converted to a *.cub file format, ISIS tools can be used. These include hiclean, hipical, and hidestripe.

Hiclean does just what is says. Noise introduced into the image data by spacecraft electronics is corrected. Noise can show up as vertical and horizontal lines in the raw image and other periodic manifestations.

Hipical is a newer tool that performs calibration on the image data. For example, flatfield and gain corrections are performed by hipical. Hipical will be upgraded as we learn more about our instrument in its environment around Mars.

Hidestripe corrects a known striping pattern in HiRISE images.

We use other tools to collect even more statistical data about the newly calibrated image data. The HiCal pipeline will continue to be upgraded as our software matures. New statistics will be collected while corrections are added or improved.

After cleanup has been completed and a new *.hical.cub channel product created, HiCal creates a variety of jpeg browse and thumbnail images. The cleaned up channels are large, and for quick previews, these smaller jpegs come in handy.

Finally, HiCal lets the next pipeline – HiStitch – know that cleaned up channels are ready to be stitched together into CCD products.

Below is an example of raw data, prior to going through the HiCal pipeline. This image sample was taken from TRA_000873_1780; “Victoria Crater” at Meridiani Planum.

Below is the same image sample after going through the HiCal pipeline (notice that the bright vertical line in the center and the faint vertical lines throughout the image have been correctly removed by HiCal):

After a channel of raw data has been downloaded and converted into an *.IMG file, we need one more conversion before cleanup of the image can begin.

The EDR_Stats pipeline creates a *.cub file from the *.IMG file. These cube files are the file type used in ISIS 3.0, an image processing software package provided for planetary science missions by the United States Geological Survey (USGS). This package contains an entire suite of useful tools, many of which are used by our pipelines.

During the creation of a cube, a variety of statistics are gathered. For example, the number of gaps, saturated pixels, calibration pixels, and other pixels are counted. Image mean, standard deviation, and other statistics are also calculated. EDR_Stats takes these results and uploads them to our database. The resulting cube is archived in our storage directory.

The final EDR_Stats pipeline step lets the next pipeline – HiCal – know that an image channel cube file is ready for calibration processing. Let the cleanup of image data begin!

HiRISE images pass through several layers of calibration. The purpose of calibration is to make the image appear more realistic, more like how the surface really is. It makes science more possible, in general terms (Not limited to HiRISE) to determine the composition of surface materials, easier discoveries of surface features, and as a whole makes the images more useful. Irregularities arise from the camera system, from the optics, from any number of things. These features are mostly corrected out if calibration is done correctly. There has been some question as to what an image looks like before calibration, and after, and I’d like to give you an example, using our picture from Victoria Crater.

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Sorry we haven’t been posting much lately!

To tell the truth, some of us are experiencing a little bit of a lull. We’re in conjunction right now — this means that the Sun is directly between Earth and Mars, so we can’t communicate with the spacecraft. (Here’s a link with a few diagrams to illustrate this.)

The HiRISE instrument is turned off, and we’re not taking any images. However, there are other activities going on at HiROC….

We start imaging again on November 8, and a few of us are already planning for that. PSP, the Primary Science Phase, is divided into two-week cycles. The first cycle is rm001, the second rm002, etc. Each cycle has a Targeting Specialist assigned to it (this one isn’t me, or I wouldn’t have time to write this!). The Targeting Specialist works with a member of the science team, the “Co-Investigator of the Pay Period,” (”pay period” because of the two-week cycle) or CIPP. The CIPP helps to choose scientifically important targets, and the Targeting Specialist does the scheduling and commanding. They work together on coordinating with other teams, choosing camera parameters, etc. There are a lot of details that need to be worked out!

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