[GRASS-user] Working with USA Public Land Survey System

[Patton, Eric]

Henry,

Are you looking to section a vector into quadrants, or are you interested in
sectioning an analysis region? 

If you need analysis regions sectioned, you could set current region to one
of your square sections and then create a vector polygon from it using
v.in.region. If you convert the region to raster via v.to.rast, you could
try my script r.fragment which sections a raster into an arbitrary number of
smaller sections (you define how many rows and columns it gets sectioned
by). Then convert back to vector with r.to.vect

You can download the script here:
http://grass.gdf-hannover.de/wiki/GRASS_AddOns#Raster_add-ons

AFAIK, it hasn't undergone any serious testing yet (by anyone other than
me), so it should be considered beta, and probably contains bugs. However,
it may be useful. If you do decide to use it, please report any bugs to me.

Regards,

~ Eric. 

-----Original Message-----
From: grassuser-bounces at grass.itc.it
To: grassuser at grass.itc.it
Sent: 8/30/2006 9:14 PM
Subject: [GRASS-user] Working with USA Public Land Survey System

I have a set of surveyed-section boundaries* for northern California
from the United States Public Land Survey System and would like to use
GRASS to find geometric fractions of these roughly square sections.
For example, I would like to divide a particular section into equal
quarters by bisecting it east-west and north-south and then save the
northwest quarter for further analysis. Can anyone suggest a method to
do this acurately?

* Used for legal descriptions of parcels given in terms of townships and
  ranges.

-- 
Henry House
+1 530 753 3361 ext. 13
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