HiRISE coverage of the Opportunity field site, version 1.0

After analyzing the HiRISE coverage of the Curiosity landing site, I thought it would be easier to analyze Opportunity coverage, because I'd developed some good strategies along the way. Although those strategies helped, it has turned out to be much harder to summarize the Opportunity coverage than it was to summarize the Curiosity coverage, and in fact this post was two years in the making. But I've finally done it: I've located all the Mars Reconnaissance Orbiter HiRISE images covering the Opportunity field site, and figured out which parts of Opportunity's mission each one covers, and where to look for the rover and other hardware. Hopefully this effort will be useful to a few of you, academics if no one else! I've titled it "version 1.0" because I'm hopeful there will be a few more images to add later (more on that below).

One reason that analyzing HiRISE coverage of Opportunity is more difficult is because of the direction that Opportunity traveled. Opportunity did a lot of north-south driving. HiRISE images are oriented roughly north-south. That can be a good thing, because one image swath can contain many hundreds of sols of traverse. But it can also mean that Opportunity's path often crosses into and out of an image more than once -- three times is common. Another reason that cataloging all the images has been a challenge is that they performed a huge number of repeat images of the area around Victoria crater, because they were interested in watching how Opportunity's tracks evolved over time, and now they are doing the same at the western rim of Endeavour, which is conveniently parallel to the HiRISE ground track.

It became clear that in order to develop a summary of Opportunity site imaging that would be of use to people in the future, I would need to focus on answering a specific set of questions. The questions I chose to answer:

• Which grayscale images are the best ones for mapping the entire traverse?
• Which color images are the best for mapping the entire traverse?
• In what order did Opportunity enter the color images?
• Which images contain hardware (lander, backshell, parachute, heat shield, rover)?
• Which images contain hardware or tracks (or at least the places where tracks used to be) in the grayscale or color parts of the swath?

Which grayscale images are the best ones for mapping the entire traverse?

For Curiosity, the answer to this question was obvious, because there were Digital Terrain Models that tidily covered all the past and planned future targets for the rover. This isn't true for Opportunity, because the landing site is mostly so incredibly flat that DTMs really aren't needed. There are only two DTMs, in the only two places where there is substantial topography: the area right around Victoria crater, and on Endeavour's rim. Here is the information about them:

So: for the areas outside the DTMs, which images are the best for mapping the rest of the traverse? Although there are not DTMs everywhere, there are stereo pairs, which could theoretically be used to make DTMs in the future, and which have (in most cases) already been combined into 3D anaglyphs. Two anaglyphs cover most of the rest of the traverse. ESP_022380_1780 covers the area from the landing site to well south of Victoria, and ESP_012820_1780 covers the traverse's westward excursion from Victoria. There is still a gap over Santa Maria crater. HiRISE took two images in quick succession while Opportunity was sitting at that spot, ESP_020758_1780 and ESP_021536_1780; I don't see any reason why those shouldn't be an anaglyph, but for some reason, they haven't been processed into one. (There is one more anaglyph that does cover the traverse, but it's totally redundant with the Endeavour DTM, so I'm not listing it in the table, but it's PSP_010341_1775.)

Which color images are the best for mapping the entire traverse?

In general, the traverse is fairly well covered in color, but there are a couple of surprising areas that are missing. On the other hand, there is an enormous amount of overlap in the region of Victoria crater, as well as in the short section of the east-west part of the traverse that is south of Victoria. But that turns out to be a good thing, because the tracks vanish over time.

I had hoped it would be possible to narrow down the choices here, but despite the amount of overlap, nearly every image is valuable for at least some part of the swath. And the way that Opportunity wanders in and out of the color strips along the traverse really complicates things. So in the middle of writing this blog entry I changed my question to a new one.

In what order did Opportunity enter the color images?

I will list them here in the order in which Opportunity entered the color portions of the swath. Images are listed multiple times where Opportunity exited and then re-entered them. There's an asterisk (*) next to the swath names where they're listed for a second time. There are only a few gaps; I have already gone to the HiWish website to put in requests for four images to cover the remaining gaps. One of the surprising things I figured out is that HiRISE has never imaged Opportunity's landing site, or its parachute, in color! That's my highest HiWish priority.

Which images contain hardware or tracks?

Sol 957: TRA_000873_1780 (color)
Sol 998: PSP_001414_1780 (color)
Sol 1013: PSP_001612_1780 (color)
Sol 1216: PSP_004289_1780 (gray)
Sol 1302: PSP_005423_1780 (gray)
Sol 1410: PSP_006847_1780 (gray)
Sol 1584: PSP_009141_1780 (gray)
Sol 1783: ESP_011765_1780 (gray)
Sol 1858: ESP_012754_1780 (gray)
Sol 1863: ESP_012820_1780 (gray)
Sol 1949: ESP_013954_1780 (gray)
Sol 2153: ESP_016644_1780 (gray)
Sol 2465: ESP_020758_1780 (gray)
Sol 2526: ESP_021536_1780 (color)
Sol 2712: ESP_024015_1775 (color)
Sol 3361: ESP_032573_1775 (color)

Sol 3614: ESP_035909_1775 (color)
Sol 3678: ESP_036753_1775 (color)
Sol 4475: ESP_047263_1775(gray)

Sol 998: PSP_001414_1780 (gray)
Sol 1216: PSP_004289_1780 (gray)
Sol 1302: PSP_005423_1780 (gray)
Sol 1584: PSP_009141_1780 (gray)
Sol 1949: ESP_013954_1780 (gray)
Sol 2540: ESP_021747_1780 (gray)
Sol 2588: ESP_022380_1780 (gray)
Sol 3705: ESP_037109_1780 (gray) (backshell only)

Sol 998: PSP_001414_1780 (color)
Sol 1216: PSP_004289_1780 (gray)
Sol 1302: PSP_005423_1780 (gray)
Sol 1584: PSP_009141_1780 (color)
Sol 1949: ESP_013954_1780 (color)
Sol 2540: ESP_021747_1780 (gray)
Sol 2588: ESP_022380_1780 (gray)
Sol 3705: ESP_037109_1780 (gray)

Sols 0 to 998: PSP_001414_1780
Sols 0 to 1216: PSP_004289_1780
Sols 0 to 1302: PSP_005423_1780
Sols 0 to 1584: PSP_009141_1780
Sols 0 to 1949: ESP_013954_1780
Sols 0 to 1864: ESP_021747_1780
Sols 0 to 2572: ESP_022380_1780
Sols 92 to 2424: ESP_037109_1780
Sols 362 to 2153: ESP_016644_1780
Sols 406 to 957: TRA_000873_1780
Sols 522 to 1013: PSP_001612_1780
Sols 742 to 1410: PSP_006847_1780
Sols 912 to 1863: ESP_012820_1780
Sols 916 to 1783: ESP_011765_1780
Sols 929 to 1021, 1202 to 1813, 2335 to 2581: ESP_028459_1780
Sols 1673 to 1858: ESP_012754_1780
Sols 2375 to 2526: ESP_021536_1780
Sols 2383 to 2465: ESP_020758_1780
Sols 2614 to 3361: ESP_032573_1775
Sols 2623 to 2712: ESP_024015_1775
Sols 2361 to 2593: ESP_046485_1780
Sols 2375 to 2526: ESP_021536_1780
Sols 2383 to 2465: ESP_020758_1780
Sols 2589 to 3576: ESP_035408_1775
Sols 2614 to 3361: ESP_032573_1775
Sols 2623 to 2712: ESP_024015_1775
Sols 2629 to 3678: ESP_036753_1775
Sols 2656 to 4475 (discontinuous): ESP_047263_1775
Sols 2661 to 3614: ESP_035909_1775

Please feel free to let me know if this information has helped you in any way!

Some notes:

• To find images, I went to ASU's Global Mars Data website and queried the HiRISE images using a box extending from 354.2 to 354.7 degrees east and -2.5 to -1.9 degrees north.
• The following color image coverage gaps need to be filled:
  • Over the landing site and early traverse: gap bounded by ESP_037109_1780 on the west, ESP_012754_1780 on the south, ESP_013954_1780 on the east, and covering at least as far north as the extent of ESP_013954_1780.
  • Over the westernmost excursion of the traverse: color swath adjacent to ESP_016644_1780 and overlapping slightly, centered near the same latitude, does not need to extend so far in latitude (1/3 the height would be sufficient)
  • Over the final remaining gap: it looks a bit too wide for a single image. Gap is bounded on the west by ESP_020758_1780 and on the east by ESP_018846_1780. Centered at similar latitude and having similar extent as ESP_021536_1780 would work, although it might be nice to push the extent farther (to match extent of ESP_020758_1780) to pick up interesting terrain in area.