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;-))
Posts Tagged ‘validation’
To conclude our exploration of the pipelines that take raw channel files and create a beautiful, unmapped mosaic, let me introduce the Stitch pipelines: HiStitch and HiccdStitch.
The HiStitch pipeline combines the matching HiCal products for the same CCD into one more-or-less lined up CCD cube file. HiccdStitch combines these HiStitch cubes into RED, IR, and BG mosaics.
Both pipelines take some time, as overlapping pixels are accounted for and brought together. After these mosaics are created, additional steps create smaller jpeg files for easier viewing, and full-sized jpeg2000 files. We use these jpeg2000 files for validating our images.
There are later pipelines, but we first validate the HiccdStitch products: Did the previous pipelines work correctly? Did the uplink team command the camera correctly? Is there haze or clouds obscuring our view of the surface?
If everything looks good, and we have received the correct reconstructed SPICE ephemeris data, then the geometry pipelines are invoked. These pipelines project the images mathematically to a model of Mars and add geometry data to the images so that each pixel becomes a point on Mars with latitude and longitude coordinates.
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 first HiRISE image data of the Primary Science Phase (PSP) arrived in Tucson last night sometime around 9 PM. Although we thought the first data might not arrive until early this morning, I was a little antsy and took a look from home around 9:40 PM to see a complete first observation ready for validation.
We are waiting for reconstructed SPICE ephemeris data, which comes out every Wednesday – starting next week – before sending these data through our geometry pipelines, and ultimately releasing them to the scientific community and public. Last time, we forced images through our geometry pipelines using predicted SPICE kernels; we do not want to double our workload by continuing that practice. The SPICE kernels released next Wednesday will cover some of the images captured this week.
Once the images have been visually and statistically validated and the matching SPICE kernels have arrived, one of the downlink folks will send the images through the geometry pipelines. We also need to get a select group of captions written and automatic caption information generated for the rest.
We are producing JPEG2000 products now in addition to smaller jpeg browse images, to be ready for our viewing client when it is ready for public release. However, there are many different JPEG2000 viewers and plugins already out there to start practicing with. One example is ExpressView from LizardTech.
Once we are on a roll, the data release will be steady and no one will be able to keep up with the wealth of Mars data coming in. Until the first public release of PSP images, we will try to provide here on HiBlog more details about the many tasks that must still be completed.
I decided the blog does not have enough pictures, so a few of us gathered around a MacBook Pro and said “Cheetos!”. Audrie is on the left, I’m next, Kite is next to me, and Tahirih is on the right. Yes, Kite has Princess Leia hair. No, I’m not a nerf herder. Who’s scruffy-looking?
Audrie, Tahirih and I did not previously appear in pictures on HiBlog because during transition imaging we were busy working in our offices and Tuvas for some reason did not visit us. We feel so left out (joking)! The three of us make up HiRISE Downlink Operations, which includes downloading new images, processing them, and image validation (the Student Validators also participate in this task). Audrie also works on instrument monitoring and safety. Tahirih also does most of the geometry processing. I also eat cheetos and chocolate cake. When Kite is not busy with HiRISE Uplink tasks – which is generally NEVER – she is blasting her way out of impossible situations that often involve walking carpets.
Some of you out there may be asking: what happens to a HiRISE image between the time that it is taken and the time that it is released to the public? Well, I’d like to give a summary here.
My new temporary daily routine here at HiRISE Operations:
- Validate the image data that have arrived since last time I checked. Are the raw image files we receive gap-free and are the file sizes as expected? Did the Uplink team command the HiRISE camera properly? So far, they have a perfect record!
- Keep checking to see if new data is arriving for processing.
- Are our automated processes running properly?
- Is the data being stored correctly and can the team access the images in the appropriate places?
- Finally! Actually look at the new images. In between “oohs” and “ahhs” check to see that the images look good. Did our automated software handle the data correctly? Do I need to do any manual reprocessing of image data?
- Report my findings to the team via email.
- Get up and see what the scientists and other team members are up to.
- Eat some Cheetos.
- Repeat as necessary.
- A million other tasks.
By the end of the day I am covered in Cheeto dust (joking) and amazed by some new vista of Mars (seriously).
What is it we find so amazing? I can only speak for myself, but in observation TRA_000823_1720, the boulders lying about casting shadows indicate just how “Hi” resolution the HiRISE camera can go. In the second observation – TRA_000825_2665 – the stack of water ice and dust layers and the patches of water frost make for a distinctive landscape. At this resolution, there is a marked difference between the north polar region on Mars and the pictures I have seen of the Earth’s own polar regions.
To me, this is the great joy of planetary science: seeing new vistas that are at once familiar and unfamiliar, and never, ever routine.