The Forestry Forum

General Forestry => General Board => Topic started by: Wudman on June 04, 2003, 07:03:44 AM

Title: GPS Units
Post by: Wudman on June 04, 2003, 07:03:44 AM
Howdy Folks,

I am looking into purchasing an inexpensive handheld GPS unit.  Primarily, I want to be able to map harvest units and calculate acreage and map road systems to incorporate into a GIS system (ArcView).  

Any input on units and software that you may be using would be appreciated.  Thanks for the Help.

Wudman
Title: Re: GPS Units
Post by: Tillaway on June 11, 2003, 12:30:22 PM
Wudman,
Define inexpensive... it seems that interacting directly with ArcView requires a professional reciever and software solution.  However you can bypass this by  importing and exporting in an ascii format.  The problem with this is that you are very limited wth the type of data you can collect with the consumer GPS's.  Generally it is better not to even try to collect lines or area features with them.  Use a series of waypoints and connect the dots for area and lines.  Also naming and feature descriptions are a PITA and are limited.

The best receiver and software solution I have found is from CMT  www.cmtinc.com (not a link).  The PC-GPS 3.8 software is excellent.  It is much simpler and has tools specific to forestry.  I have found it much more fuctional for map making than ArcView.  The receivers are much less expensive than Trimble, Thales, Sokkia, etc. and are actually just as or even more accurate when compared with these units.
Title: Re: GPS Units
Post by: Wudman on June 12, 2003, 08:46:16 AM
Thanks for the reply Tillaway.  When I said inexpensive, I guess I meant cheap.  We've tested units from CMT, Trimble, and Northup on the high end scale.  I have decided to go with a Garmin Etrex Legend which I found for $139 after rebate.  I'll use this in conjuction with "GPS Utility" written by Alan Murphy and a script that will allow this data to be converted to a shapefile.  Once into a shapefile, I can import it into ArcView and utilize it in our GIS system.  The accuracy of these units is sufficient for our purposes.  To quote from Dr. Rich Oderwald, a pencil line on a 1320 scale map is 40 feet wide.  Thanks for your input.

Wudman  
Title: Re: GPS Units
Post by: Kevin on June 12, 2003, 05:33:20 PM
I have the Etrex Summit and the only beef I have is that the navigation numbers are too tiny.
I don't know if they've made any improvements as of late.