Google Mars HiRISE base images for Opportunity Options

[elakdawalla]

Because it has become a forum FAQ, I've created this sticky thread containing information on where to obtain new base images for Opportunity's traverse for Google Mars, and for discussion on creating new ones. I will continue to add links to new base image layers to this first post as they become available.

New users: Download this 4-MB kml file and open it in Google Earth
Then go to the last post in the Opportunity Route Map thread for the latest traverse map
You need to download the new KML file each time in order to follow Opportunity's peregrinations.

Google Mars comes with a color base image mosaic created from HRSC imagery. In addition, there is an inset full-resolution HiRISE image covering the area from the landing site at Eagle crater, through Victoria, up to the point between sol 2040 and 2041 (just west of Mackinac) where Opportunity drove off the map.

Unfortunately, this Victoria crater HiRISE layer included within Google Mars is not perfectly registered to the HRSC base map. As far as is known, there is nothing to be done about that. Both John Cody's image layers and Eduardo Tesheiner's traverse maps are aligned with the inset HiRISE layer included with Google Mars, NOT to the HRSC base map.

In June 2009 SFJCody posted a reduced-resolution mosaic of HiRISE tiles that cover the entire future traverse area including Endeavour's rim. I have made some small modifications to that map and have hosted it in a single file here (17 MB). Download the file, run Google Earth, select the Mars view, and File>Open the KMZ to view it.

In September 2009 SFJCody posted another HiRISE base image, this one at full resolution, covering the Western Route and reaching not quite all the way to Santa Maria. Here is a link to the kml file (4 MB). Here is a link to a zipped version if you'd prefer to have it locally (256 MB) and I also wrote a blog entry about it.

During the discussion below, in late 2010, I created a small tile that covers just the immediate area around Santa Maria. Here is a link to the kml file covering that region.

In February 2011 Eduardo Tesheiner provided another set of base images covering the area from Santa Maria to Endeavour's rim. Here is a link to the kml file. If you would like to work from a local copy, you can download this 75 MB zip file and unzip it to a folder on your drive, then open the file PSP_010341_1775_RED.kml within it.

All three base images can be loaded at once using this kml file (the same one that is linked to at the very top of this post).

[elakdawalla]

OK, we are almost there, but not quite. I downloaded MapTiler and ran Eduardo's selected of the Santa Maria image through it. In a matter of two minutes MapTiler generated 1000 tiles and associated KMZ files with a single KML file in the top directory. When I opened the KML file in Google Mars, bingo! It worked just as Eduardo said. The numbers for the corner coordinates aligned the tile nearly perfectly with the existing map (it's offset to the northish by about 3 meters, give or take a meter). So far so good. That is a solution that will work for people -- as long as they are willing to download 20 MB worth of data per 8000-pixel-square image tile.

But Eduardo suggested that I save everybody a lot of hard drive space and hassle by hosting the image tiles at the Amazon S3 server (where the Planetary Society serves large files) so that people don't have to download the entire enormous map. Using MapTiler I specified the location of the S3 server (http://planetary.s3.amazonaws.com), and it regenerated the tiles, KMZ files, and KML files. The top-level KML file looks like it points to the right place:

CODE

<Link>
        <href>http://planetary.s3.amazonaws.com/santamariatest/0/0/0.kmz</href>
        <viewRefreshMode>onRegion</viewRefreshMode>
      </Link>

However, when I try to open the local copy of the KML file in Google Mars, it does not *quite* work. (Please try it for yourself: here's the KML file.) It's really puzzling, because it's not a matter of a broken link. It is clearly finding the georeferencing information within the KMZ files to correctly locate the corners of all the image tiles, but the images are not showing up:


What is really weird is that if I point my browser to one of the KMZ files, it finds the image data just fine. For instance, try http://planetary.s3.amazonaws.com/santamariatest/0/0/0.kmz (the very same link listed in the code block above, which is the lowest-res tile, the "apex" of the image pyramid) for yourself, and you should see this:

It works! So I don't understand why opening the KML file does not work.

Here is what I did with MapTiler. Help me figure out where I am going wrong and why the image tiles aren't showing up.
Tile Profile: Select Google Earth (KML SuperOverlay)
Source Data Files: Locate local file. I started with a PNG version of the image Eduardo selected, the tile that overlaps Santa Maria; I set the black pixels transparent using Photoshop. Click on its name and "Georeference" button. Put in 4 coordinates listed by Eduardo in green text in his post above, in 'north south east west' order as software specifies.
Spatial reference system: I selected WGS84. I wonder if we should be specifying some Mars-specific projection here -- but WGS84 seemed to work OK for the locally stored version of the map.
Tile Details: Accepted defaults (min zoom 0, max zoom 5; Hybrid JPEG + PNG)
Destination: Result directory: I specified the name of a local directory (the path to the image plus the folder name "santamariatest", so in the end it was "C:\Documents and Settings\Emily\My Documents\Google Mars\james canvin's images\santamariatest"); Destination URL: "http://planetary.s3.amazonaws.com"
Viewers: Google Earth (KML SuperOverlay)
Viewer Details: I specified a map Title (this is just metadata)

[Tesheiner]

However, when I try to open the local copy of the KML file in Google Mars, it does not *quite* work. (Please try it for yourself: here's the KML file.) It's really puzzling, because it's not a matter of a broken link. It is clearly finding the georeferencing information within the KMZ files to correctly locate the corners of all the image tiles, but the images are not showing up:

It's working perfectly for me.
It takes some time to download the first time but all LODs are working.