Basic SeisWare Data Loading Instructions for Mars Radar Data
Written by Than Putzig, 2013 Feb 7

When you create a project in SeisWare, you will need to choose and configure a projection system. I typically start with a standard Earth system, usually WGS 84 in either a UTM zone or one of the polar stereographic projections, whichever is nearest the area of interest for the particular project. Edit the projection parameters to use values appropriate for Mars. See the accompanying Screenshot1_projection.tiff, which shows a coordinate system customized for Gale Crater. Here, I started with UTM Zone 53S and then modified values for False Easting, False Northing, Semi-major Axis, Semi-minor Axis, Inverse Flattening and some of the "Name" fields.

After you get a project created, you'll want to load SEG-Y radargrams, created previously using the IDL procedure RAW2SGY (which may also call RDR2SAN if you are using PDS standard SHARAD products as input). Begin the process by selecting "Seismic > Data Loader..." in the SeisWare main menu. Once you have the SEG-Y file(s) for your project selected, click the "Read Header" button on the second screen of the Data Loader window. You will need to override the data format (it comes up as "IBM Float" but should be "IEEE Float"). The sample rate for the PDS radargrams should read "0.750 ms". The true sample rate is 75 ns, so this is off by a factor of 10000. We do this on purpose because SEG-Y requires a unitary sample rate, which SeisWare reads as microseconds. The factor applied in RAW2SGY is 10000 rather than 1000 because the sampling of the radargrams from the other processors in use internally to the SHARAD Team is 37.5 ns. See the accompanying Screenshot2_headers.tiff. Two screens later in the Data Loader (you can accept defaults for the screen in between), you will need to select a keyword file that tells SeisWare how to read the headers -- see the accompanying Screenshot3_keywords.tiff and the accompanying COSHARPS.kwd file. You can take default settings for the rest of the Data Loader screens. After the tool finishes running, you will find new SEG-Y file(s) in the project directory.

Once the SEG-Y data are loaded, you will need to load the location file produced by RAW2SGY in order to post the radargram ground track on the SeisWare Basemap view. Select "Seismic > Import Locations..." on the main menu. On the "Import Locations" dialog, select "2D Columnar ASCII" under "Type of Input Files" and select "Match CDP" under "Import Into". Then use the "Files..." selector to find the *latlon* location file(s) that was created previously. Next, click the "Define Columns..." button and then the "Load Format..." button that comes up on a separate window. Select the COSHARPS_latlon.txt file. See the accompanying Screenshot4_locations.tiff. Click "Ok" on the screens and you should see status messages indicating that the location file(s) were loaded.

Next, bring up "Seismic > Line Properties", select the newly loaded data, and select "Edit > Activate". Then run "Launch > Basemap..." from the main menu. You should get a map view of your project area. If you don't see the ground tracks, you may need to adjust the Basemap settings. In particular, select "Edit > Layer Visibility..." and toggle off the "Use layer visibility control".

Radargrams can be displayed either by double-clicking ground tracks on the Basemap or by using the "Seismic > Line Properties" dialog to select a particular observation and then selecting "Tools > Seismic Viewer...". You will likely want to adjust the seismic viewer properties ("Edit > General Properties"). If you began with PDS data, copy the accompanying "FPS display properties.xml" into the project subdirectory "Properties/ViewerProperties" and use the "Load..." button on the Seismic Viewer Properties menu for a starting point. Once you have the Seismic Viewer displaying the data properly, experiment with the "Pick Horizons" tool and try displaying the associate horizon ribbons on the Basemap.