MARSIS data visualizationusing open source tools

Anton B. Ivanov (anton@psi.edu) Ecole Polytechnique fédérale, Lausanne, Switzerland

Planetary Science Institute, Tucson, AZ.

Overview

•What you need to know

•Access and plotting tools

• vanilla, GMT

• IDL

•Goal for today

• Show a simple example of MARSIS data use.

Structure of MARSIS data

grd2cpt d1885.grd -E256 -Cgray > ddd.cpt

•What you need to know to process MARSIS data

• Get a Mac • On Windows you can get by using Cygwin

• Get vanilla executables• http://software.mars.asu.edu/vanilla/

• there might be an updated version of vanilla for more efficiency

• I can highly recommend GMT for plotting solution

• MOLA datasets come very useful for analysis

Software set

vanilla• Originally developed at Arizona State

University to access MGS TES data

• Provides a database like access to PDS table data.

• has capability of joining datasets. In MARSIS case we join radar data and geometry

• provides facilities for easy data search

• use with MARSIS data require additional description files in the data directory

Use of vanilla with MARSIS

•.FMT files • have to be copied into every directory where data resides

• located in LABEL directory

•dataset file• it is not necessary to have many separate files, it is possible to

have just one master file

• in order to increase efficiency of search it makes sense to have subsets of dataset files. For example, 3XXX or 4XXX files.

• possible to select either part of an orbit, the whole orbit or set of orbits (e.g. lat /lon locations)

vanilla examples

• vanilla dataset.ss3 -fields -select • list of fields can be found in .FMT files

• grep NAME FRM_SS3_TRK*FMT is very useful command.

• possible to select either part of an orbit, the whole orbit or set of orbits (e.g. lat /lon locations)

Simple example

•How to plot tracks using vanilla and GMT.

• make sure all the LABEL files are in the directory

• vanilla -files GEO*DAT -fields "SUB_SC_EAST_LONGITUDE SUB_SC_PLANETOCENTRIC_LATITUDE" > orbit.dat

• psxy orbit.dat -JM25 -R-180/180/-60/60.125 -B30/15:."MARSIS coverage": -Sc0.07 -H1 > orbits.ps

A bit more complex

•Look at what data was taken• vanilla -files FRM_SS3_TRK_CMP_RDR_1885.DAT -fields "OST_LINE_NUMBER C_LOL "

• Retrieve actual data

• vanilla -files FRM_SS3_TRK_CMP_RDR_1885.DAT -fields “DIP_F1_R_-1"

• Retrieve data for dipole Freq 1, real part, doppler -1 into a binary file (native float). Take only data for OST line number 5 (essentially retrieve a certain frequency band of data )

• vanilla -files FRM_SS3_TRK_CMP_RDR_1885.DAT -Bfm d1885.dat -fields "DIP_F1_R_-1" -select "OST_LINE_NUMBER 5 5"

• this line produces a file with 469 records and 513 bytes header. Format : 4 byte native float.

• xyz2grd d1885.dat -Gd1885.grd -I1/1 -R1/469/1/512 -ZLTfs513

• grd2cpt d1885.grd -E256 -Cgray > ddd.cpt

• grdimage -JX4/4 d1885.grd -B100/100 -R -Cddd.cpt > d1885.ps

Browse product

Complex browse product

1855

IDL

•Use standard PDS tools to read data table by table

•read_vanilla

• I have put together a simple IDL script which is essentially an interface to the vanilla utility

GIS

•It is quite possible and useful to integrate MARSIS tracks into a GIS (ArcView or GRASS).

• Makes sense for analysis of data coverage, quality

• Integration with other datasets (e.g. MEX HRSC data)

• Hard to integrate MARSIS browse products

•It is quite possible to produce .shp files using vanilla interface. This is a task in progress. Let me know if you’re interested.

Caveats

•With respect to vanilla tool there are still a few issues

• current datasets contain small errors

• standard vanilla tool does not work in database sense• however allows working with the data file by file

• labels have to be fixed in order to allow better handling of the data.

• all of these will be fixed in the next data release