Does anyone out there use a Trimble?

[+biosearch]

I've got the chance to use a trimble, one of the better ones, with the antenna pack, etc. Was wondering if anyone out there used one, has used one, uses one for work (surveyor, etc.). Would like someone to discuss issues and quirks concerning these units. Something about being able to place a cache and having sub-foot accuracy for the coord give me a kick, why I don't know....

[+JustAnotherGeek]

I work on and sell Trimble GPS along with Sokkia GPS units...mostly to Surveyors which need extremely accurate GPS units (sub-centimeter or better).

 

The Sub-Foot GPS units you are refering to use post-processing either onsite or back at your home/office to process the sat data to get better accuracy. In these post-processing units you have to stay stationary on the point you are taking a reading at for anywhere from 30min to a few hours (depending on sat coverage).

 

As we all know...when we are hunting for caches or whatever...the accuracy is not very good. But if you were to record all the readings for about 5 minutes over the same point and average the readings together you can have a better and more acurate reading of the true coordinate. The averaging is what the post-processing procedure does...it helps you in placing the caches and recording the cache coordinates...but it won't help you as far as accuracy in finding them.

 

There is one GPS system called RTK (or RTTK) which uses a Static Base GPS unit placed over a known position (surveyed or processed) along with a Roaming/Rover GPS unit. Since the Base is placed on a "known" point...it can calculate an "error" between this point and whatever the sats are telling the base it's at. This "error" is brodcasted (RF) to the Rover which in turn takes the same sat signal of where the rover is and uses the calculated error from the base to calculate an extremely accurate position Only problem with these RTK systems is that it's not cost effective for caching (costing more than 20K for the system).

 

KE4MUR

[+Hoosier_Daddy]

I am a land surveyor, albeit not a licensed one. I have used a trimble 5700 and 5800 a little bit. Let me know what your questions are, either here, or on my email, and I'll see what I can tell you. I may be able to consult others at work on Monday who can offer more answers.

 

Hope I can help!

 

p.s. I didn't scroll down to see if there was a reply. Go with ke4mur. He's probably MUCH more qualified to give you a correct answer.

Edited November 11, 2006 by Hoosier_Daddy

[+Moore9KSUcats]

It might be fun to place a cache and then see what kind of "error" other people get or comment on when finding a cache, but if you were using an extremely accurate unit finding a cache someone else has hidden, you still have their measure of unit error to contend with. It may bring down the error circle some for finding, but I don't know how much.

 

We got one of the newer GPSr units with the super chip (Garmin 76 cx), and have been real pleased with its coverage under trees and beside cliffs. We have posted updated coordinates on a few tough finds in our area where people have had trouble finding the cache. (Error on those caches was maybe 40 feet or more, due to tree or cliff interference.) Several commented that our coordinates did help find the cache.

[+biosearch]

Thanks for the information already and once I get my hands on the unit I may just be e-mailing one or two of you to discuss it. I'm thinking of using it more for placing caches then hunting for them. The post prucessing software, along with the pack antenna which I also have available, should give me a far better location then I would get with my magellan.

 

I am interested in the idea of taking multiple readings and averaging them, however, I know that there is some error to this still. I am wondering how to average, or is there a program that is able to accomplish this?

 

Thanks...

[astrodanco]

I hate to dredge up an old thread, but what the heck...

 

Thanks to Ebay, some eight years later (!), I now have dual frequency survey grade RTK ability as well. Being able to do RTK is the bomb. Being able to use the local RTN and not needing my own separate base is a bonus. (But I also have my own base to play with.)

 

I am interested in the idea of taking multiple readings and averaging them, however, I know that there is some error to this still. I am wondering how to average, or is there a program that is able to accomplish this?

If you want better accuracy you can do a static survey, collect data for somewhat over four hours and submit your data online to OPUS for post processing. Repeat that at different times on several different days for comparison purposes.

Edited May 7, 2014 by astrodanco

[+Roman!]

I hate to dredge up an old thread, but what the heck...

 

Thanks to Ebay, some eight years later (!), I now have dual frequency survey grade RTK ability as well. Being able to do RTK is the bomb. Being able to use the local RTN and not needing my own separate base is a bonus. (But I also have my own base to play with.)

 

I am interested in the idea of taking multiple readings and averaging them, however, I know that there is some error to this still. I am wondering how to average, or is there a program that is able to accomplish this?

If you want better accuracy you can do a static survey, collect data for somewhat over four hours and submit your data online to OPUS for post processing. Repeat that at different times on several different days for comparison purposes.

 

That’s one more find for me! Thanks so much for hiding this geocache.