Do not use any 360 prisms in your traverse if you are, they will get you bad results. Trimble 360 prisms should only be used for topo and stakeout.
The S6 has a built in barometer in it. Only need a good thermometer.
Thanks for the suggestion, I will try that. Things have picked up here at work and haven't had time to run the test loop. Trying the 3 leg traverse will probably be much more do-able with my time constraints.
Just wanted to refresh this for anyone else who may have this issue.
We ran into exact same issue (relatively same traverse length and misclosure).
I discussed with our Trimble representative.?ÿ
Solution Part 1 (and most important): Turn "active tracking" to "semi-active" in prism settings. This tells the gun to look for the glass and not the lights.
Solution Part 2: Make sure prism is rotated to have one piece of glass perpendicular to gun just as you would a convention prism.
This solved our problem.?ÿ
Sounds like a ~$3000 traverse kit would've saved you a lot of money in the long run...
How long are your loops?
I've found that when using a -35mm offset prism that isn't Trimble traverse kit -35mm, use a custom prism type and key in the offset.
Having some Leica prisms, I toggled between custom and traverse kit and was consistently getting different readings.
How much of a difference??ÿ You know you can't use the offset printed on a Leica prism for any other brand of equipment...:
Found this with a quick search:?ÿ?ÿ https://www.lasersurveyingequipment.com.au/latest-news/42/leica-prism-constant-explained.html
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It was sub-hundreth for x,y & z, but there was always a difference.?ÿ I didn't take the time to find out if the errors were compounding over multiple set ups.
Is it just me, or does 1:20,000, 1:30,000, and 1:50,000 sound like good closures? I have topcon gpt8205 that I have gotten over 1:50,000 with, but I also get many 1:20,000 + closure with it as well and never worry about it. I can't say I ever remember getting over 100,000 with it. I call that luck.
This is all singling the angles and running the older style A6 360 prism with it, and taking the traverse shots with tracking mode which I assume is the same as autolock on a trimble.
I am doing primarily residential and rural boundary and residential home construction stake-out work.
I have been meaning to upgrade the prism which I will probably post about soon in another topic.
I read that you are using 30mm offset prisms and I assume tilting ones at that, so I guess my comparison is not totally valid.
The comments about tripods are spot on as you do need the best ones with robotics or at least in my experience. I had some closure issues when I first got my GPT8205 Topcon, as I continued using the same tripod I had with my conventional total station, but I upgraded by a suggestion from Troy Deaton to a Crain Trimax and I have had good results ever since. I have been using that same Crain since 2007 too.
Ben
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@ Ben Davidson
On small acreage surveys, there is very little difference between 1:20,000 and 1:75,000.
I remember one particularly defiant setup from the late 1980s that no one of the half dozen that tried to double an angle and none had satisfactory results, averaged error was ?ñ20". It was at a poopnot hill along a rural road and the only place to setup and see both directions. An enormus oak was on the east side of the road and a root ran under the setup and its natural state of rocking to and fro was causing the error.
Bottom line, not all locations are suitable for setting the instrument. The tell is in the results and not how hard you try.
That sort of error sounds like a distance constant error. If your angles are doubling and add uo to what the figure dictates that would be the likely culprit.
Look up 'ABC distance meter check' in your search engine. It's a simple routine that will tell you what sort of constant error you are dealing with.
