I'm new to this group
I took some surveying classes in college and worked briefly on a couple of survey crews, but I've never taken the time to learn how to run a total station.
My current job requires me to survey longitudinal and cross-sectional profiles of creeks.Ā Until now we've been using a laser level and long measuring tapes.
I'd like to start using a total station to do these surveys and have some colleagues who are willing to show me how.
Anybody have any tips/recommendations for this type of work?
My colleagues use a Nikon DTM 521 for their surveys and I found one on Ebay that's within my budget.Ā Any comments on that unit?
Any input would be greatly appreciated.
Thanks,
--Kirk
Replies
Trig levels can dramatically cut down on field time and produce a moreĀ accurate surface model (t-net).Ā Ā However it is also prone to more errors. The only way to combat this problem is to incorporateĀ redundant checks in that dataĀ acquisition when using this method. There are a few ways you can do this.
1) Run conventional levels through your control points that the total station will be making observations from.
2) Shoot a known control point as a backsight with your total station so that you can compare the trig elevation to your conventional elevation before you start gathering data.
3) After you have made your observations turn back to your backsight and observe it as your last shot from that setup.
One of the ways to avoid errors is to fix the height of the prism pole either all the way up or all the way down. This helps filter out mistakes in prism pole height. Another trick is to fix the prism at the height of the instrument thus avoiding a prism height and gun height correction. These methods can be employed depending on the terrain and sight line problems of your particular project.
As an unrelated note if you are required to make observations at a certain interval or pattern within a certain tolerance then you can generate coordinates for a grid graphically, input those into your data collector and then be able to turn your instrument to the designated grid intersection faster than your rodman can walk to that spot. This method avoids having to stake grid lines. This is done by simply taking a piece of paper and drawing a graph with an x,y axis. You make coordinates along the appropriate axis of the graph (i.e. 0, 50, 100, 150, 200) depending on what your minimum observation interval is. Do this for both the x axis and the y axis. You can now enter those coordinate pairs for the grid intersection you are trying to observe into a data collector and generate a right angle and distance to it.Ā
Hope this is helpful.Ā
Hey Kirk,
Choosing a Total Station depends on the actual circumstances like the Jobsite you are going to use it and the distances you are working on.
Ā
The Nikon units are pretty good but if you want me to help you more personally and find out if you could use even a cheper unit, Ā feel free to Shoot me an Email: [email protected].
Ā
Best.
Mike
Mike