Are you using SurvNet and how is it going? I have been trying to learn the system and have watched the webinars on it. My concerns are:
-Most of my work is of the Conventional Loop variety. Is SurvNet the right tool to reduce my closures with least squares?
-SurvNet seems pretty complicated and I think it will take a while to learn to use it properly. C&G editor is used in the webinar and we always use raw data editor. It would be nice if there was a webinar using raw data editor instead.
-How do I include Vectors from OPUS data into my reduction? I have no experience post processing my own data. I either run RTK on localized coordinates (based on a balanced loop, or I RUN OPUS to establish State Plane Coordinates for a couple of control points.
-Raw Data editor also has a Least Squares reduction, is it any good? On a closed loop what are the differences?
I understand the strength of least squares is that you don't have to run conventional loops, but with the VA state standards the way they are, they still require a closure. They also have a note about maximum permissible positional uncertainty based on the 95% confidence level.
Is that a term related to least squares? Does anyone know of a good class I can take to help me learn more about least squares and implementation into my work.
Thanks in advance.
Survnet is pretty easy to use .
Hers some tips.
Put control in a separate file , txt file . For opus you will just have north east coords in a separate txt file .
Make sure raw file is clean , get all garbage out of it.
Put vector rtk data in a Seperate file.
Follow the setup box , you will know if it works correctly.
I took a class on it a while back and it was a VERY good class. Mr. Goodman and Carlson taught it themselves.
If you want to get the most bang for your buck with ANY least squares program, throw in a cross tie or some GPS data.
It will still work with conventional loop, but it showed me the true possible error - larger than I thought.
Another great method is, as you traverse around a project if you can see a cell/radio tower in the distance take angles only observations to the same spot on it (and call it the same number). In some circumstances this can work great to help contain angular error. The caveat with this approach, though, is that the spread of angles across the network to the remote object must be large enough to allow for some strength of figure.
If there is a delta from on end of the project to the other of, say, 5 degrees you'll probably introduce more additional error than what it eliminates; which makes this approach rarely helpful.
I took a Carlson class at the Kentucky Conference earlier this year. It was a great class. I believe it was Mr. Goodman and Mr. Carlson taught it.
Larry Phipps has good DVD that he sells. I can recommend it as being a good class/course on the subject. I learned a lot when I watched it.
Good luck.
I'll try to answer some of your questions.
SurvNET is valid for any type of traverse, even simple loops. However, the statistics are more meaningful if you have redundant measurements as in networks of traverses.
The OPUS "extended" report has the raw vector data in it and we can extract that information for processing. Instead of processing the vectors though, most people will use the calculated OPUS coordinates as control points and assign them a reasonable standard error based on the report.
The Least Squares routine in the Carlson Editor is a true least squares program. However, is designed to process individual traverses and is not as flexible as SurvNET when it comes to processing complex data sets.
Any certification asking for Positional Uncertainty, Positional Tolerance, Positional Accuracy or Positional Precision requires a statistical report like the one created in SurvNET. These terms refer to relative error between two points shown to a certain confidence level.
SurvNET can also calculate closure information but you have to define the traverse by listing the point numbers in a "closure file". This is necessary because SurvNET does not require the measurement data to be in any specific order so it can be difficult to determine the traverses.
I would be happy to help you set up a project in SurvNET and answer any questions you have about the report.
Dean Goodman
Carlson Software