[Hvcatskillcewg] Terra sync vs ArcPad

[Joshua Clague]

Raphael,

 

Welcome to the world of land and easement management in the Hudson Valley!
It's nice to have another GIS/GPS user in the community and as I'm sure
you've already noticed, we've all leaned a lot from each others experiences.


 

I think that when purchasing the Trimble GeoXT, you will generally be happy
no matter what software and peripherals you also get, but I'll share with
you a few lessons we learned along the way.

 

1.	Software: We use ArcPad instead of TerraSync.  We made this decision
because like most GIS users, we have ArcGIS desktop software and wanted the
transition from field to office to be as painless as possible.  So far we
are happy with this decision.  Keep in mind that if you are buying the GPS
from an authorized Trimble dealer, they will most likely sell TerraSync (a
Trimble product) as superior to ArcPad, but this may or may not be the case.
I have heard good things about both.  An advantage to ArcPad that we have
encountered is that some 3rd party extensions (i.e. The Nature Conservancy's
invasive weeds management database, called 'WIMS') are both free and
available to other land trusts, but will only work on ArcPad.
2.	Differential Correction for Maximum Accuracy: We made the decision
to go with Beacon receiver to get real-time differential correction instead
of post processing.  Looking back, I would have gone the other way around
for two reasons: 1. We don't need the high accuracy in real-time, but only
when we're doing our mapping in the office.  Although I've never used it, I
think using the GPS Analyst extension on your desktop for post-processing
would be less painful than lugging the Beacon receiver all day.  The results
will be the same either way, and the cost is not much different ($1800 for
Beacon receiver vs. $2000 for GPS Analyst).  2. Although this doesn't happen
often, occasionally we lose the Coast Guard beacon signal that provides us
the real-time accuracy.  With post-processing, this won't happen.  
3.	Antenna Reliability: When we were sold our GeoXT, the salesman told
us that tree cover in the Summer would not really effect our ability to get
clear satellite signals.  This was absolutely NOT the case.  Actually, we
even had a hard time getting signals in the winter in heavily wooded areas.
This was very discouraging at times, so we bit the bullet and bought an
external antenna (called a Hurricane antenna) and the results have been
amazing.  Weather and vegetation cover are never an issue anymore.  The only
thing that blocks the signal now is the land itself (mountains, valleys,
etc.)  This antenna did come at a cost though: $900 including the mounting
backpack. 
4.	Signal Reliability: As you may know already, there are occasionally
windows of time when the satellite coverage in a given location is not
sufficient to provide the desired accuracy.  As Russian and European
satellites are integrated into our GPS system, this is becoming less of a
problem but it still can occur.  Our Trimble salesmen never told us about
this, but Trimble has a free software program, available for download, that
predicts when these 'blackouts' will occur and can graph them for you.  We
now always use this before going into the field to make sure we're in the
clear.  You can download the Trimble planning software at:
http://www.trimble.com/planningsoftware_ts.asp.  Pleas keep in mind that
when using this software, you will need to include and regularly (once a
week?) update an ephemeris file that has all of the satellite information.
Trimble also maintains this file and makes it available at:
http://www.trimble.com/gpsdataresources.shtml .

 

I hope this information helps in some way but it not too much information!
Please feel free to call if you have other questions.  And..good luck!

 

Josh            

 

  _____  

From: hvcatskillcewg-bounces at lists.ltanet.org
[mailto:hvcatskillcewg-bounces at lists.ltanet.org] On Behalf Of Raphael Notin
Sent: Monday, November 19, 2007 6:16 PM
To: hvcatskillcewg at lists.ltanet.org
Subject: [Hvcatskillcewg] Terra sync vs ArcPad

 

 

Greetings,

 

I am starting a stewardship position with Winnakee Land Trust. I am
currently gathering some information concerning equipment as we are looking
into acquiring a GPS unit. I would appreciate some advices concerning GIS
software. 

 

We are about to buy a Trimble GeoXT with a Geo-Beacon receiver. But to go
with it, Trimble recommends the Terra sync Pro Pathfinder office software
while ESRI pushes me toward ArcPad within their Geo-collector Submeter
package. The price difference is not very significant; I am most interested
in the functionality and ease to use. (FYI, we use ArcGis 9).

 

What would you recommend for easement monitoring? 

Do these two options actually provide the same services?

I would welcome any other comments on this equipment.

 

Thank you for your help.

 

Raphael Notin

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.ltanet.org/pipermail/hvcatskillcewg/attachments/20071120/173ceabd/attachment-0001.html