Guys,
I'm new to the forum, and have a question about level loops with a total station. A little background:
I used to work in SC near the coast, and we did a LOT of elevation certificates. My former boss had a way of using his Trimble S6 similar to the way one would use a transit for running level loops. That is, he would use it strictly for vertical data collection, which means we wouldn't have to set up on each traverse point, zero, etc. and it saved a lot of time! But I never learned how to do it....
Well, about a year and a half ago, I took an opportunity to move to HI for a Land Surveying job. Until recently, we didn't do many elevation certificates, but now with FEMA's new Biggert-Waters legislation, we are seeing more and more of them coming in the door.
I am wondering if you guys could tell me how to run level loops with Survey Pro software and a total station. It could end up saving me a LOT of time!
Thanks
-Arthur
I have never used a total station for trig leveling. I do have some papers that Jessie Kozlowski shared some time ago.
These won't help with the Survey Pro portion, but hopefully it will help.
Good luck!!!
Set instrument height to zero, target height to your pole height. Take a shot to the prism and with Vd (Vertical distance) on the display you can note this down for back sight and foresight. The vertical distance shown should allow for the target height, worth checking first though.
Only difference to normal level booking is that is negative Vd is equivalent to a positive staff reading and vice versa.
Come to think of it getting survey pro just to display simple things like Ha Hd Vd for manual booking always seemed to be quite difficult during the time I used it.
I think you have to use "side shot" and record a point each time you measure, but you can observe the VD on a result tab.
Or I think there used to be a survey basic mode you used the star button to get to. I think that was slope distance only though.
I would probably use the remote elevation function in Survey Pro. You still have to book the elevations because the DC is going to ask you which elevation you know. I don't remember if Survey Pro has a trig leveling routine. In any event I would run the vertical collimation routine prior to commencing any work. I know people who this routine exclusively and get excellent results.
charlie, jesse and james
yes, charlie and jessie are authorities on this subject. they should both be available.
james ray is good at this as well. you might want to check in with him. i think i still have his contact if you need it.
Good links, Jimmy! Thanks.
Dave
Why not use the proper tool - a level?
Because it would take 50 turns to run down that cliff.
You will get best results using a tilting prism and taking repeated shots just as in traversing.
Trig levels with total station
Precise trig leveling using methods outlined in Jesse's article yield excellent results, especially using a motorized robotic station with multiple sets of vertical angles. Some tips: Run your compensator routine on each different setup. Set station and target height at zero (you're measuring DIE between instrument and prism). Use a fixed height pole with a tilting prism. Do NOT mix poles.
The method is especially useful for solo robotic crew. Applicable for transfering elevations from hidden BMs under canopy to GPS observable points, measuring down cliffs, across narrow bays, etc.
I do not know if SurveyPro has a trig level routine. You may need to book the DIE. Good luck.
Regards,
Mike Moran
And...?
I forgot to say the Vd (others call it DIE?) should be observed on both faces. You can also do as many repeated sets as you want and average the measured Vd.
Curvature and Refraction compensation is built into most instruments as well. This should be checked for long sights.
Just watch that first step, it could be a doozy.:-O
:good:
How to run "trig heighting" loops with a total station
Anyone else bothered or confused by the original title? In my mind, you can only run "level" loops using a level. Where i came from (UK), you'd run "trig heighting" loops using a total station. Just curious, don't want to make a big deal of it...
How to run "trig heighting" loops with a total station
Technically, you are correct.
I've worked for at least two companies that never owned a level.
We used a transit for our level loops with great results.
I haven't used an actual level since the '80s myself.
Most data collector have an ELEV option to run in 3D mode and carry elevations.
I have a cogo program that has an option when adjusting the traverse to also adjust the elevations obtained on that loop, either to a closed point and/or to a known point with an elevation for a non closed run.
I recently set a monument on a knoll with good visibity aside a 250 acre lake for a flood study.
It is easy with the TS to setup, measure HI and shoot the current water level on a pier and transfer an elevation to the water surface for use all around the lake.
As they say, good enough for dirt grade.
0.02
How to run "trig heighting" loops with a total station
Read the papers written by Jessie! It works and is a real time saver. My problem with using the method is that it is not standard practice and it is difficult to get peers to go along with it. I like the comments of surveyors that use this method maybe it will become more common in the future.
It would be great if the data collector programmers would write software for this method because it can get confusing doing it long hand. My 2 cents, Jp
How to run "trig heighting" loops with a total station
Thanks, everyone, for the helpful advice!
Yeah, I really like the papers posted up earlier, very helpful. And I agree, there should be more user-friendly program features for trig leveling.
I will have to try running some loops using these methods, and report back...
Thanks again,
Arthur
I ended that article asking manufacturers to write trig leveling routines. It took years, but now there is one called Level Me for Survey Controller and Access written by SETTOP. I got a nice email from them -
