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;-))

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.