MAPGEN

[Ken Sibley]

Jill,
You might want to post this message to the SCS gis bulletin board as well
as send it to analysis, am, etc...

Ken Sibley
PS - Good info to know.


> From grass-lists-owner at max.cecer.army.mil Fri May  6 15:38:12 1994
> Date: Fri, 6 May 94 15:12:28 CDT
> From: jschuler at ncg.scs.ag.gov (Jill Schuler)
> Sender: grass-lists-owner at max.cecer.army.mil
> Reply-To: grassu-list at max.cecer.army.mil
> To: ngardner at ncrds.er.usgs.gov, grassu-list at max.cecer.army.mil
> Subject: Re: MAPGEN
> Cc: jschuler at ncg.scs.ag.gov
> Content-Length: 3033
> 
> %%%----- Begin Included Message -----
> %%%%
> %%%Our version of Mapgen4.1 will not work when we
> %%%are using a Latitude and Longitude Projection.
> %%%
> %%%The following text demonstrates the process going into the
> %%%interface.
> %%%
> %%%When setting up the location we responded to
> %%%the question concerning ellipsoid as sphere.
> %%%This is what the DEFAULT_WIND looks like:
> %%%rncrds0:34> more DEFAULT_WIND
> %%%proj:       3
> %%%zone:       0
> %%%north:      33N
> %%%south:      32:52:30N
> %%%east:       92:45W
> %%%west:       92:52:30W
> %%%cols:       2500
> %%%rows:       2813
> %%%e-w resol:  0:00:00.18
> %%%n-s resol:  0:00:00.159972
> %%%
> %%%Creating PROJ_INFO & PROJ_UNITS with
> %%%g.setproj works fine, here are the PROJ_INFO & PROJ_UNITS file:
> %%%
> %%%rncrds0:35> more PROJ_INFO
> %%%name: Latitude-Longitude
> %%%proj: ll
> %%%ellps: sphere
> %%%
> %%%rncrds0:36> more PROJ_UNITS
> %%%unit: degree
> %%%units: degrees
> %%%meters: 1.0
> %%%
> %%%When going to mapgen for the first time with
> %%%An error occurs, which allows us to go no furthur:
> %%%
> %%%The PROJ_INFO file for Location <long_lat_test> 
> %%%is not in the correct format.
> %%%Please run the command g.setproj from the PERMANENT mapset.
> %%%EXITING ..........................................
> %%%
> %%%Is it possible that our errors come from the way the software
> %%%was loaded onto our system?
> %%%
> %%%
> %%%We would also like to know if there is a driver for either
> %%%the Calcomp 1044 or the Calcomp 5800 Series Plotters for 
> %%%mapgen4.1 .
> %%%
> %%%----- End Included Message -----
> 
> > The MAPGEN documentation states that g.setproj should add '"es" or "e"
> > and "a" values' to the PROJ_INFO file.  However, it does not.
> > 
> 
> Unfortunately, at SCS we very seldom use the LL projection.  
> When I revised the mapgen4.1 script for compatibility with Jerry's 
> mapgen4.0, I assumed incorrectly that all PROJ_INFO files would record 
> the same information.  Other projection's PROJ_INFO files set a and es 
> ellipsoid parameter values.
>  
> The LL PROJ_INFO file does not record this information.  
> If you must work in LL then manually add the es and a values to the 
> PROJ_INFO file.  The values and format for the PROJ_INFO file are:
> 
> name: Latitude-Longitude
> proj: ll
> ellps: sphere
> a:6370997.0
> e:0.0
> 
> The 4.12 mapgen interface is not fully functional with a LL mapset.  You
> will not be able to use the make.fill command in lat/long.
> 
> 
> Give me a buzz back if you have any more problems.
> 
> Sincerely,
> 
> Jill
> 
> *********************************************************************
> 
> #  # #### #### ####      ######  #### ##### Jill R. Schuler
> #  # #    #  # #  #      #      #     #     USDA 
> #  # #### #  # #### ### ####   #     ####   Soil Conservation Service
> #  #    # #  # #  #        #  #         #   National Cartography and 
> #  #    # #  # #  #       #  #         #    GIS Center
> #### #### #### #  #   ####  ###### ####     P.O. Box 6567 
> 				            Ft. Worth, TX 76115
> e-mail: jschuler at ncg.scs.ag.gov             Phone: (817) 334-5559 x3086
> 
> *********************************************************************
> 
>