Help

[Virginia Jackson]

Help      Help     Help    Help             I am a GRASS beginner.




I need some help from the GRASS community concerning the following:

    1.  General overview of how to use GRASS 4.1
    2.  Data loading instructions for DMA (ITD) data

Please read on if you think you can enlighten me.  




Acronyms

    DMA      Defense Mapping Agency
    DTED     Digital Terrain Elevation Data
    ITD      Interim Terrain Data
    UTM      Universal Transverse Mercator


Part 1.  General overview.

I am new to GRASS and I would appreciate a general explanation of
how to use GRASS 4.1.  An example that demonstrates the order in which 
processing should be done would be helpful.  I just requested the ftp 
document grass4.0/documents/grass_doc.wp.Z in the hopes that the manual 
is complete enough to walk a beginner like me through GRASS using the 
sample Spearfish data.

I currently have the following tutorials:

    Performing Boolean Operations in GRASS 4.0:
        r.combine Program Tutorial  (December 1991)
    GRASS 4.0 Map Digitizing Manual:  v.digit  (December 1991)
    GRASS Tutorial:  DLG-3 Data Extraction  (April 30, 1992)
    GRASS 4.0 Tutorial:  DTED and DEM Elevation Data Extraction
        (December 1991)
    GRASS Tutorial:  Image Processing  (undated)
    GRASS 4.0 Inference Engine:  r.infer  (December 1991)
    Performing Map Calculations on GRASS Data:  
        r.mapcalc Program Tutorial  (December 1991)
    A Tutorial for "TIGER in GRASS"  (December 1991)

Please feel free to reference them or to suggest another document. 
Do tutorials exist for GRASS 4.1?


Part 2.  Loading DMA (ITD) data. 

Last week I loaded GRASS and some DMA (ITD) data on our Sun from tape.  
My long range goal is to load the DMA data into GRASS, perform Boolean 
operations on the data, and extract the resulting DMA data from GRASS.
For now, I will settle for being able to load the DMA data into GRASS.  
I reviewed the DMA data extraction tutorial; however, my data is not 
in DTED or DEM format.  I have the following data files in ITD format:  

    hyd_line.add        obs_line.add
    hyd_poly.add        obs_poly.add
    hyd_pt.add          slope.add
    loc_line.add        surf_mat.add
    loc_pt.add          veg.add
    
According to the README file in my data directory, 

%    Each file contains data records which represent either points, 
%    lines or polygons (regions) with the following record format:
%
%        1.  Record number
%        2.  Polygon Attribute String
%        3.  Number of Vertices
%        4.  Vertices
%
%    Vertices are given in UTM coordinates.

Is ITD format close enough to DTED format that I can trick GRASS into 
thinking my data is in DTED format?  Do I have to extract the data from 
a tape?  If the data is already on-line, do I still "extract" it for
GRASS? 

Thank you in advance for your help.


Virginia Jackson
Engineering Research Associates
e-mail:  jackson at era.com
phone:   (703) 734-8800