Error sources of a total station measurment

Unless you meant it in the subcategories comment, HI and OH measurements are two big ones. Calculation errors which can include bad entries for coordinates and such.

Also time, maybe not strictly "error", but mismanagement of time causes all sorts of havoc.

A loose nut behind the knobs.

Changing temperature as when the instrument is brought from storage indoors to the field. Or strong sun on one side causing differential warming.

Histeresis (ie/stability) of the tribrach and tripod.

Snow and Ice, other forms of unstable ground.

I realize you are looking for more high-end procedures, but based upon my long experience with stupid survey crew tricks:

Running the gun in the summer but still using the winter settings (really)

Forgetting to actually set up diredtly over the point, leaving them wondering why they miss the backsight a tenth of two.

Taking a shot on the prism while the wind is blowing and the rod is wobbling all over (no bipod anywhere to be seen).

Histeresis (ie/stability) of the tribrach and tripod.

Pretty much begins and ends here. If a crew cares enough to take care of the tripod, likely they will do the rest. If not, there isn't much point to the rest.

Thanks for all the replies so far.

Yea I would consider measuring HI/HT under instrument and target centering error. It would be the vertical component. But you are quite right. There is a ton of vertical error that can live here.

Changes in temperature and differential warming is a great point. I always try to stress that my field crews let their instrument acclimatize. Cold drives with those windows down boys. It causes a collimation error but it may deserve a category on it's own as its more of a temporary collimation error. Thanks for this, I think I will separate it.

I did have unstable ground/tripod instability on its own but being that it can be argued as a subset of standing axis error I took it out and lumped it in with that. Maybe that was the wrong decision. Unstable ground causes the instrument to sink off level (standing axis error) but a poor quality tripod introduces more error that just that.

I never knew Hysteresis was the actual term before. Thank you very much for this. Added. This is why I love this forum!

Bruce, I believe what you're describing would fall under instrument and target centering error.

I also forgot pointing & reading error. It's a random error that not much can be done about it other than taking extra shots and using the mean but it's an error none the less.

Strong winds and vibrations from earth compaction machines ,or heavy excavators digging on site. If you look through the scope in these conditions, the crosshair and the target are all blurry. I'm assuming that the ATR doesn't do a great job locating the center of prism.