2.25.2008

TopCon (GMS-2) v. Trimble (GeoXT) for GIS Data Collection

Here is a rough assessment of the two GPS units. I recently conducted a field trial on the GMS-2. Most of my experience is with a GeoXT. Both of these work pretty much the same with the same kinds of data collection issues. If the GPS receiver is obstructed, the accuracy goes down, even with post processing). In Sacramento ("The City of Trees") we have this problem and with tall buildings or near the sides of buildings (i.e. water meters, tree inventory, sign inventory).

TopCon

Pros

-Accept Glonass (Russian) Satellites (i.e. more satellite coverage than other GPS units)
-Built in Digital Camera (very cool!)
-Pictures are automatically downloaded and hotlink field is automatically maintained
-Can add Flash memory
-WAAS correction
-Post processing or real-time correction with additional modules/software

FAST (Form Building software)

-Easy to create
-Easy to import to GPS unit
-Can add a component for Digital Camera and/or GPS if desired
-GIS add-on will allow for export to shapefile and can see GPS data on ArcPad

Cons

-Form and ArcPad do not integrate
-Can only see current point within ArcPad interface
-Must convert .DBF file to Access Table, then import into the FAST Form to update existing records
-GIS workflow is not as streamlined as GeoXT (more steps and must build a process to manage and maintain a unique ID)

Accuracy (submeter - 2-3 meters, depending on satellite coverage and post processing capability)

Cost

(~$5000-6000, includes all hardware/software - GMS-2, FAST with GIS capability, post processing software)

Trimble GeoXT

Pros

-Straight forward GIS workflow (must use Trimble GPS Analyst and GPS Correct)
-Completely integrated with ArcPad
-WAAS Correction
-Post processing with GPS Analyst or add-on real-time correction beacon and software

Form Builder software

-Build forms through ArcPad or ArcPad Builder

NOTE: You can use TerraSync (field data collection) and Pathfinder Office (post processing and form building), but this will not work very effectively for use in an ArcGIS environment, thus I don't mention it.

Cons

-Digital Camera separately attached
-Photo management on back end or through additional software
-No Glonass satellite reception

Accuracy (submeter - 2-3 meters, depending on satellite coverage and post processing capability)

Cost

(~$4000-5500, includes all hardware/software - GeoXT, GPS Analyst/GPS Correct, ArcPad)

7 comments:

Anonymous said...

thanks... i had just heard of the topcon line and was looking into comparisons. ive used various trimble gear quite a bit. i dont necessarily need the camera so i might stick with trimble... Glonass would be nice though

Anonymous said...

I'm going to sell my GMS-2 on Ebay... keep you eyes open

GPS Navigation said...

Nice survey! Thanks for publishing informative post.
Regards
GPS Navigation

Anonymous said...

Topcon has added full ArcPad functionality using their Field Tools extension.

Glonass is a very nice addition, surveyors have been enjoying this from Topcon for many years.

Did the XT cost include a camera?

Anonymous said...

http://inovagis.com/downloadables/Response%20to%20Trimble%20White%20Paper.pdf

Anonymous said...

Here is a link with the whole story about the "White Paper" from Trimble !

http://www.inovagis.com/ger/gps-empfaenger.htm

Naticus Maximus Cartographica said...

Apparently, TopCon has some new information out about this unit. Read through it. Some of the information on my blog can be updated. It looks like the TopCon Unit works a little more seamlessly than what I experienced. This may be newer functionality than what I tested or the sales person I talked to did not provide me the additional resources to test.

Basically, they are comparable. It depends on your project workflow and data managment requirements.

See my additional post regarding the sign inventory that was also published in ArcUser Winter 2009.

NMC