There are three stages to validation: quick look validation, in-depth validation, and geometric validation. Most of the validation is done by undergraduate students in a variety of departments from the University of Arizona. If they notice something odd, they flag it and notify the full-time operations team, who do a more detailed analysis. Currently there are two students who work solely with validation, and me. I volunteer when their work load becomes heavy (normally I work as a programmer for different software needed at HiROC).

The first stage is to let the staff at HiROC know quickly if there is any problem in commanding, or if there is haze in the field of view. Low resolution “browse” images that have come down in the last 24 hours are examined by someone (usually either myself or RichardLeis) to see if there is anything obviously wrong. If there is suspicion, a flag is raised and then other people will take a look at the images. This quick look helps prevent any commanding issues from continuing, and also helps us avoid taking more pictures in areas with some kind of atmospheric distortions (”haze”). This could include dust storms, clouds, melting ice caps in the polar regions, etc.

The second stage of more in-depth analysis involves a tool called HiVali. This tool allows one to quickly take a look at an image in more detail, and see if there are any kinds of problems with it. It reports statistics of pixels to see if there is saturation or low contrast. It checks to see if there are any gaps in the image, and other kinds of routine image checks. One part of this process, the part that takes the most time, is the visual validation, where a human physically looks at every inch of the picture in high resolution to see if there is anything odd. These are usually things which can be fixed in the calibration processing.

The third stage is also a quick look, which is done after the image has been geometrically projected. If something is found that is strange in this stage, then the geometric processing is re-done to correct the error. If the image is in good condition, then many of the intermediary files are marked for deletion. Note that the EDRs and the final products are always kept, but there are several stages to the pipeline, as readers of this blog will know.

Sometime during this process, science team members also look at the image, to find if there is anything of special interest in the image. If there is, a caption is written, and it is prepared for the next batch of images to be released. If not, the image may be released without a special caption. All images will be released within 6 months of being taken. Once everything is perfected at HiROC, this release time will be reduced greatly, perhaps even to a few weeks. Currently, though, we are still working on the process of getting the images released.

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.

During and after the validation process, the images are reviewed by several of the science team members of HiRISE. Things of special nature are noted, and these images receive captions. The others are slated for a more general release. Due to the large size of the HiRISE images, it is almost impossible to search every square inch of the pictures by any one or even a small group of people. I’m sure many of you have noticed this with just the images which have been released, there are many more which are still being validated which have yet to be released.

The Systems team is responsible for making sure that the HiROC computers are all working in top shape. They are quick to find problems when they arise and fix them so that it does not affect the flow of data here. They are preparing servers for two upcoming services that HiROC will provide, HiWeb, which was mentioned previously, and a JPIP server, which will allow for the effective distribution of JPEG 2000 images.

The software team is writing software that will make people’s lives easier. Some are working with the HiPlan suite of tools, which is used to plan upcoming images, to make it even easier to use for the uplink team. Some are working on HiVali, the validation software, which is used to make it easier to verify that an image is ready to release to the public, quickly finding problems with the image. Some are working on HiView, a program which will allow distribution of images over the JPIP protocol to the general public. Still others are working on getting HiWeb ready for public release.

Let me also talk a bit about a few upcoming products mentioned in this entry. HiView will allow you to download only the parts of a HiRISE image that you find most interesting. It will work great, even for those who have slow internet connections. I personally have tested this with a connection rate of 1kBytes/sec, and it works reasonably well even at that slow speed. It will allow the user to save the parts of the image they find the most interesting to their hard drive for future study (HiView will require a constant internet connection to download the image)

Another upcoming product is HiWeb. HiWeb will allow any user (Yes, that’s you!) to suggest future targets to image with the HiRISE camera. Preference is given to targets of scientific interest. The suggestions are given a priority, and placed in a database to be targeted depending on the orbit of MRO and the allocated bandwidth.

So, that’s what’s happening at HiROC these days. In short, we are all very busy, but very much enjoying our work. I personally can’t remember a time that I’ve had as much fun working as these last few months have been. And surely the best is yet to come!

I would just like to offer my thanks to all of those who helped to make HiRISE at Ball Aerospace, the flight engineers at JPL, operations team, programmers, targeting specialists, scientists, and everyone else involved in the project. The long period of preparation is over, and now we begin with the real thing. Have a fun 2-year PSP all!

This is an example of a HiRISE image pre-calibration. Notice the vertical streaks across the image. Harder to see is something known as dark current, which appears with any camera if a black picture is taken with it. There is also variations of pixel sensitivity, all of which must be accounted for. This doesn’t include the special calibrations needed for color images, but there are some as well.

This is the same image in roughly the same spot, taken after the calibrations have been done. Note that there is no longer any vertical lines, at least, none that are obvious. That is one of the things that is corrected during calibration. There are several other things which are done as well, but they aren’t as visible, but the image as a whole has been made more scientifically useful. There is always the risk of cutting into the useful part of an image, but HiRISE has several advantages in this respect. HiRISE has a high SNR, or Signal to Noise Ratio. SNR is exactly what it sounds, the ratio of the signal (In our case the light reflected from the Martian suface) to the noise (Which can be anything from Thermal noise, Cosmic Background Radiation, etc) With HiRISE’s large mirror, and pushbroom CCD arrays, it is able to achieve what hasn’t been achievable in other cameras. What this means is that even relatively dark surfaces are still visible to a degree with HiRISE, which has not been the case with most previous imagers.

Calibration images are taken to assist in this process. They are mostly taken by pointing HiRISE at the dark side of Mars, with various temperatures, recording what image results. There are a variety of what’s known as Stim lamps to give an approximation of white light as well, which also assist with calibration. The results from these images (Which are all very small) are placed into a database to know the correct way to calibrate each image. All of these are done so that everyone can see Mars the way that it was meant to be seen.

1. The image is taken by the HiRISE camera, and is stored in up to 28 channels, two for each of the 14 CCD arrays of the camera. Each channel covers about half of the image. Of the 14 CCDs, 10 are red CCDs, two are blue-green, and two are near-infrared. The color CCDs are aligned with the center red CCDs.
2. The image is placed inside a buffer on MRO, awaiting transmission to Earth, along with science data from the other instruments on MRO.
3. The image is received in packets by the Deep Space Network (DSN).
4. After 4 hours of collecting data at the DSN, the Jet Propulsion Laboratory (JPL) puts the packets together for what is known as a “quick look”. The entire image generally has not yet been received by this point in time, but it is enough of the image that it can be processed to take a quick look at it. Subsequently, JPL puts together all of the data it has received every 4 hours and makes it available to the computers at HiROC.
5. After the files have been put together by JPL, then one of the computers at HiROC looks and sees that there is data on the JPL server and copies the data to our system at HiROC. This is the start of what is known as the pipeline, the system of programs at HiROC which process the images. This usually happens either via a direct connection to JPL (slower), or through the Internet 2(Faster, but sometimes can be bogged down).
6. The images are put together into a viewable format, using the minimum processing possible, and create what’s known as an EDR, or Experimental Data Record. This is done without calibration, stitching together the channels, or any other processing, aside from putting the image together. For an image which uses all 14 CCDs, there will be 28 EDRs. These generally speaking are of mainly scientific interest, but they will be released to the general public via the Planetary Database System (PDS). They will be in the standard PDS format.
7. After the EDRs have been created, they are converted to another format for ISIS. ISIS, the Integrated Software for Imagers and Spectrometers is a suite of tools used for processing images for most interplanetary missions, that was developed by the United States Geological Society (USGS). Most of the tools that we use at HiROC for processing our images are written for ISIS files.
8. After the ISIS files have been created, they are calibrated via a program called HiCal. This reduces the inherent noise of the camera to be more consistent with what is being photographed. All digital cameras create some level of noise, and while HiRISE is an extremely good instrument, it still generates a low level of noise.
9. After the individual channels are calibrated, then they proceed to a program called HiStitch, which puts the two channels of the same CCD together. As they are a part of the same CCD, this requires little processing.
10. Next, after each CCD been stitched together, the full CCD images run through a program called HiccdStitch. This program puts the different ccds together, making a mosaic for each color band. This requires some processing, as the ccds slightly overlap, and it can sometimes be difficult to match the different arrays exactly.
11. If the image has not been completely received, then at this point, the pipeline stops, until JPL has received the entire image, or if there are a few confirmed gaps in the image which we haven’t been able to recover. Transmission over the vast distance between Earth and Mars is not easy, and even the best systems have some small error.
12. After the image has been completely stitched together, then the image is geometrically projected. To understand this, realize that the images that HiRISE takes are flat, while Mars is actually round. Geometrical Projection alters the image so that the image points in compass directions, while correcting any distortions that are created by the ellipsoidal shape of Mars. With the geometrical projection images and the right software tools, such as qview for ISIS, the exact distance can be found between two point on the image. In order for this to happen, we must wait for information to be gathered on the exact position of the spacecraft. This is done by the nagivational team, based off of the downlink frequency. This takes two weeks after the picture has been taken, so Geometric Projection might take a while. This is the longest wait point of the operation. An image can be released from predicted information, however, most images will wait for the correct SPICE kernels to be calculated, in order to get the best information. If an image is geometrically projected from predicted information, it will be calculated with the correct info after it has been received.
13. The images are then validated by a team of students known as the HiRISE Validators. They check to make sure that everything in the pipeline worked perfectly, see if there are any gaps in the images, and other similar tasks. If they notice a problem, they contact the HiRISE Operators, who will take steps to resolve the problems, which may include passing part or all of the image through the pipeline again, or tweaking the software to make it work perfectly.
14. The image is converted to a format that the general public can use. Currently that format is JPG, or TIFF, but eventually we will use JPEG 2000.
15. After all of this, the science team members of HiRISE will look at an image to see if there is anything noteworthy. If there is, it is given a caption, and perhaps a press release. If not, it will be posted on the HiRISE website. They are also posted on the MRO website, and occasionally on others.

This process may take as long as a week or two to complete, depending on the load of MRO, scheduling concerns, load at HiROC, etc. The first image took about 9 hours to be completely processed after it was taken by HiRISE. The Victoria Crater picture, taken during a much busier time on MRO, took about 36 hours to make its way to our hands. This was in part due to the larger size of the image, as well as the cache of images already awaiting transmission on MRO to earth. The captions for the images taken during Transition imaging took anywhere from a few hours to a few weeks to write, and this will likely continue to hold. We at HiROC want to release the images we take as fast as possible to the public, and we are doing everything we can to realize this goal. Several shortcuts were taken during the Transistion imaging phase that allowed for images to be released quicker. For Primary Science Phase, this will take a bit longer because these shortcuts will not be taken, but we expect that we will release most images within two weeks after them being taken, shortly after we have finished receiving, processing, and captioning the image.

There are some variations to this process, for example, the Victoria Crater picture was released in a press conference jointly with the Mars Exploration Rovers (MER) team. Also, color images require extensive calibration and take a lot more time. However, this is the general idea. Currently the entire system, except for writing the captions and adding the images to our website, is essentially completely automatic for receiving and processing HiRISE images, due to years of preparation by the HiTECH and HiOPS teams.

For those interested, let me give you an idea what we are up to. The targeting specialists are starting to find the next places we’ll image. We are getting ready to start our regular imaging meetings, which will take place biweekly, to discuss the locations to image during the upcoming weeks.

HiOPS, the Operations team, is reviewing the operation of the camera, still verifying that everything was taken correctly. So far HiRISE appears to have operated nearly perfectly.

HiTECH, the technical support team, is making some adjustments to our software, tweaking it so as to make sure everything is running perfectly.

HiEST, the engineering team, is analyzing the telemetry of the pictures, and making sure everything ran as expected. Their report was that the instrument is in perfect condition.

Everyone is still looking at the images we have already taken, and the HiRISE internal email is full of cool segments of pictures, and commentary about these pictures. Everyone is very excited for the next batch we will receive!

So, we are all getting ready for Primary Science Phase. It’s amazing to think we’ll be able to get these high-quality pictures for such a long period of time! We are all just waiting to see what will happen. All that we really know is, we will learn many new and exciting things about the Red Planet, more than we have ever known before. And we can’t wait to do so!

The picture being shown currently is the part of the first image we have currently received. We still haven’t received the entire image, it is coming in soon.