Best Method for Leica Viva least Squares

> Has anyone ran a large least squares network with Leica VIVA/LGO and if so, what was your approach? Leica doesn't make it very easy to store the "same point" over and over and I have never really used LGO for a least squares adjustment. Thanks!

Yes, I have. It's been a couple of years, so my recollection of the details is faded. It seems that I had to edit point numbers in LGO. Have your field crew number subsequent ties of the same point as PNa, PNb, and so forth (were PN is the point number). Beware, LGO doesn't always reactively update the way it is supposed to and will yeild garbage until it does. Restarting the program, or changing something and then changing it back will usually, eventually, force the update.

LGOs approach is actually better than StarNet for truly large adjustments. As in statewide large - spanning SP zones large.

Aaron23,

I may be misunderstanding what you are say about Leica makes it difficult to store points multiple times. With Leica you can store the same point number 10,000 times with each individual observation set attached to it. The system averages the coordinates of that point when 2 or more observations are made and each observation is stored seperately. There is an averaging limit that you can set in the job parameters that warns when an point exceeds a tolerance when averaging. So, again I am not sure what you.

What instrument are you using?

LGO can easily take in the observations for performing a least squares adjustment. You will need to have the 3D adjustment license installed. StarNet also offers a Leica Importer that will import the Leica data files directly into a StarNet project. If you need the System1200 and Viva can export a RW5, RAW. or an FBK formatted file with the traverse data.

> Aaron23,
>
> I may be misunderstanding what you are say about Leica makes it difficult to store points multiple times. With Leica you can store the same point number 10,000 times ...
I have always found that field crews are really freaked out about the idea of overwriting a point. I agree with you, of course, that it can be done in Viva, as it can be in most all dc software. And the tool for averaging observations in Viva is pretty cool.

Norman,

I have always "battled" the point numbering method in training sessions with crews. I think it is just because in most older field software a point ID could only be used once and everyone is in the habit of renaming points when observing them. Most users finally acclimate to the method and like it. I remember that I had to get use to it myself when I first stating using Leica software.

Thanks for the reply. I've seen the averaging function on the VIVA but never really understood the use for TPS. I have used it for GPS when shooting several windows, but I assumed that the Leica software does only what it says "averages" and wouldn't be a true least squares.. CAD also doesn't allow you to pull in the same point number so I don't know if the averaging function would be useful or not. Does LGO allow multiple points with the same number or? My equipment is TCRP1203 and a Viva CS15.

You can have as many measurements on the same point as you wish, each time you store, you are storing the measurement (wether single or averaged) along with the point. If you are out of your set tolerances, then the software will report it.

>... I think it is just because in most older field software a point ID could only be used once ....
I think that the vast majority of data goes unadjusted. Most crews have rarely experienced having their data adjusted. They tie it once, and that's the "control". Overwriting that "control" is to lose that control, or at least to throw things into a confused state. Sad, but I think that it is the norm. (But not this Norm.)