CALTECH MOLA and MOC ArcView Demo
1.) ArcView Interface with Viking MDIM version 1 (Approx. 1 km/p).
2.) MOC context image (250 m/p, Boxfiltered with a 201 box size). One reason for using MOC mosaic is better registration of MOLA. Registration between MOC and Viking varies from approximately 6-14 km, and could possibly be higher.
3.) MOC context image (zoomed in to middle). This MOC context images was created in ISIS using the MOC context images that have been released to this date. This image was created from 15 MOC frames averaging 250 m/p. The processing used mission specific software in ISIS, including a boxfilter to normalize the contrast between the images (this decreases albedo information, but makes the mosaic look better, though in this case it did not fix all the seams - it is a crude method for tonal matching). After processing and geo-referencing, the images were mosaiced. Explanation of ArcView image registration included with MOC NA (see below) images.
4.) MOLA points over MOC context image. The MOLA points were selected using the PEDR2TAB program (available from the MOLA team). A lat/long box is chosen and PEDR2TAB outputs all the MOLA points that fall within the range into an ASCII file. This ASCII file is brought into ArcView via an Avenue script that allows ArcView to translate the file to a shapefile. ArcView operates best in an earth-based longitudinal system (-180 to 180 positive east), so all MOLA data has to be converted from the MOLA longitudinal system (0 to 360 positive east) to terrestrial (this involves the Avenue script simply recalculates the 0-360 system into the -180 to 180 system).
5.) Surface interpolated from MOLA points. This is done using the spatial or 3D analysis in ArcView This surface was created using a cell size of 1000 m, via an inverse distance weighted (IDW) algorithm with a fixed radius of 9km and based on the topography data.
6.) Contours generated from DEM surface. Again, part of the spatial or 3D analysis available in ArcView
7.) Location and direction of profile 1 over MOLA Dem
8.) Profile 1. Generated with 3D Analyst ArcView extension using DEM. Exaggeration 10x
9.) MOC narrow angle image over MOC context image (Note the 2 KM shift). During LEVEL 2 processing, the images are resampled to a Martian projection. Once this is done, the ISIS labels contain the information that ArcView needs for image registration. This data is written to a world file with the same name as the image, but different extension. The equations below will calculate the middle of the upper left pixel in meters (these are still being checked for correctness)
x(meters) = ((SAMPLE_PROJECTION_OFFSET) * MAP_SCALE *1000)
y(meters) = LINE_PROJECTION_OFFSET * MAP_SCALE * 1000 *-1
10.) MOLA points drawn over MOC narrow angle image with some elevation values tagged. Note how similarly located MOLA points can have very different elevation values. The MOLA team has determined that MOLA's vertical accuracy is ~10m and the footprint size is 130m with 330m spacing along the surface.
11.) MOC context image draped over DEM surface in 3D. You can barely see the two MOC narrow images. Exaggeration 10x
12.) MOLA shaded relief draped over DEM surface in 3D. You can again see the two MOC narrow images. Exaggeration 10x
