Land Surveying 101 - Total Station Levelling Error

In this video I explore the errors associated with the improper levelling of a total station and how to retain good accuracy when your instrument drifts out of level.
00:00 - Intro
00:49 - Level Compensators
01:45 - Compensator Index Error
03:15 - Standing Axis Error
04:12 - The Test
05:51 - Test Results
08:34 - Final Thoughts

[@lztoniolo]

My dream is to watch an 1hour video of you just working in the field and showing your procedures to make such great science and piece of art called surveying.

[@TechWizeGuy]

I love your vids, I could nerd out on your shit all day!

[@DroneMappingTools]

Love your content! Thanks and I look forward to seeing the follow up videos!

[@markmayer5788]

I ran a similar test - not as extensively or as systematically - some years ago with a Trimble 5603 and got similar results. Up to about 3 minutes out of level the angles were consistent. I also reached the same conclusion about centering errors. Which makes resected setups all the more attractive.

[@timd9430]

Smart as a whip.

[@Alfred2695]

Great video, thanks for all the work :)

[@_JohnDo]

Excellent content sir

[@tassimotown9667]

Youre doing God-tier work!

[@murreasy]

Loved it.

[@Construction_Survey_Czar]

Do you have the list of what total stations you used? Do you have the specs on what each manufacturer states the amount of compensation their compensator will handle? In situations where resections are performed with a significant temperature shift (20 degrees F up and back down) from the start to mid day to the end of the day from one set up, and no back-site rechecks performed, how well is the typical compensator performing? This example is pretty typical for general contractors self performing their own construction staking, grade checking and running machine control with a total station and a dozer. A really great video, with good info to help those who overly complicate certain aspects of how to use instruments. Looking at myself here.
that's a pretty sweet location you performed your tests. Was that site pre-existing or did you develop that location for this and other videos?

[@The3rdDimensionSurveying]

I used a 0.5" Trimble S9. I do not have the compensator spec, only real world observations on how it actually performed. If there is that amount of temperature shift and a backsight isn't performed over an extended period of time you are going to be dealing with other error sources creeping in. I would be more worried about tripod hysteresis at that point. Whenever I was doing construction layout I would always have a backsight setup to reorient every 10-30 minutes depending on conditions. You'd really be playing with fire if you didnt have a point you can continually check into and reorient when doing precision layout.
That is a pre-existing location, I wish I had it just for video creation.

[@OnLineSystems1]

always comp. level your base before you attach your scope. feel the ground and ensure no vibration or movement occurs.

[@bobb325]

good to know, ty

[@masonhope]

good content

[@nafnist]

The sun heating one leg of the tripod, is annoying, and will affect the plummet. In a case like this, the compensator works good.
However vibrations can mess things up beyond what the compensator can handle. There times were you can not see a big change in the plummet, and only staking a controlpoint will tell the truth.

[@antvander4456]

if i level the station and do a resection on uneven ground (where it can easily move to 1 min out after a bit of time), are you suggesting that as long as I reset backsite I should still be accurate?
Also, does distance from the total station affect anything here?

[@The3rdDimensionSurveying]

As the instrument settles and BEFORE reorientation there will be an increase in error. Once you reorient, the error caused by settlement will be reduced to a negligible level, until it begins to settle again.
Distance always increases error of a total station. Both angularly and the EDM has a scaler component to the error spec as well.