GRASS Usage for Virtual Planetary Exploration

Installation: Kurt Schwehr

Documenation: Daniel Delgado and Kurt Schwehr

 
 1.1 What is GRASS?                                            1
 
 1.2 Usage for the VPE Laboratory                              1
 
 1.3 Tutorial                                                  4
  1.3.1 Logging on to the computer                             4
  1.3.2 Starting up GRASS                                      4
  1.3.3 Creating a GRASS Database for use with the Mars data   5
  1.3.4 Accessing Mars Data from the CD-ROM                    7
  1.3.5 Creating the GRASS header Support Files                9
  1.3.6 Registration using Kilauea Data                       11
    1.3.6.1 Specifiying the Location and Mapset               12
    1.3.6.2 Customizing the Database Environment and Selecting
    the Graphic Output Device                                 14
    1.3.6.3 Obtaining a Grey Scale                            14
    1.3.6.4 Grouping the first Raster Image                   16
    1.3.6.5 Targeting the First Image                         17
    1.3.6.6 Using `i.points' on the First Image               18
    1.3.6.7 Rectifying The First Image                        19
    1.3.6.8 Grouping the Three Other Images                   20
    1.3.6.9 Targeting The Three Images                        21
    1.3.6.10 Using Points on the Three Images group to prepare
    to Register with the First                                21
    1.3.6.11 Rectifying the First Image Group to the Three Image
    Group                                                     24
  1.3.7 Visualization of the Kilueau Mapset                   25
 
 1.4 Resources                                                33
  1.4.1 Software                                              33
  1.4.2 Databases                                             33
  1.4.3 Tutorials                                             34
  1.4.4 Newsgroups                                            34
  1.4.5 Programming notes                                     35
  1.4.6 GIS Mailing Lists                                     35
  1.4.7 GRASS Mailing list                                    35
  1.4.8 Useful Information obtained from the Mailing List
  Archive:                                                    39
    1.4.8.1 Compiling Grass on IRIX 5:                        39
    1.4.8.2 Mars Data                                         41
    1.4.8.3 Searching through the grassu-list archives        41
    1.4.8.4 Histograms                                        42
    1.4.8.5 Color display in GRASS explained                  42
    1.4.8.6 Running GRASS programs without starting grass     43
    1.4.8.7 Sample usage of r.mapcalc                         43
    1.4.8.8 Autocad DXF files                                 44
    1.4.8.9 Databases and GRASS                               44
    1.4.8.10 New r.in.hdf Command                             45
 
 1.5 Appendix                                                 46
  1.5.1 Stanford Workshop GRASS Tutorial                     ---
  1.5.2 C Code Written During Installation                   ---
  1.5.3 Installation Size                                    ---
  1.5.4 VOLINFO.TXT Mars CDROM                               ---

Style Guide

Word for Windows 6.0

This section does not currently apply.

This document uses 12 point Times New Roman Font.
GRASS output uses a Courier 9 point font
User input is a Courier 9 point font that is bold and italicized
GRASS or UNIX command line input uses a Geneva 9 point font
that is bold and italicized

What is GRASS?

GRASS stands for Geographic Resources Analysis Support System, and is a widely used software package allowing one to manipulate geographical information. Software like GRASS is known as a Geographical Information System (GIS). GRASS is released free of charge by the US. Army Corp. of Engineers (The FTP site for obtaining it is in Section 1.4: Resources)

The internet posts a monthly NetNews article in net.answers called the 'GIS FAQ' that answers Frequently Asked Questions about GIS systems. Two definitions cited are:

A GIS is ...

An information system that is designed to work with data referenced by spatial or geographic coordinates. In other words, a GIS is both a database system with specific capabilities for spatially-referenced data, as well as a set of operations for working [analysis] with the data. (Star and Estes, 1990)

... simultaneously the telescope, the microscope, the computer, and the Xerox machine of regional analysis and synthesis of spatial data (Abler, 1988).

A typical use for GRASS would be the creation of a map suitable for urban development. The map might be required to show vegetation, all areas that are currently range land, plus any slopes equal to or less then 15 degrees. For this application, the GRASS database would contain several types of data; such as Digital Elevation Models (DEMs) with x,y,z information, raster pictures (perhaps from LandSat photos), road locations, and vegetation densities.

With GRASS you can display these types of data easily and in relation to each other (only several display commands are needed). You can overlay the raster pictures on the DEM data, and include road and vegetation information. You can then zoom in on areas of interest, and using the database functions of GRASS, do queries for additional information.

The VPE GRASS installation contains a sample database (spearfish, located in Montana), that can be used to create a map of this type. A tutorial (Section 1.5.1 Stanford Workshop Grass Tutorial) is included that shows the procedures for this process.


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Email to:
Kurt Schwehr schwehr@cs.stanford.edu -- Dan Delgado renata@eos.arc.nasa.gov

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