gpsGeorge, post: 438234, member: 12857 wrote: I??m looking forward to digesting the material. I??ve been in the Operating Engineers (Local 701) here in Oregon since 1974. For the last 10 years I??ve been building 3D construction models, making use of GPS technology (via Topcon) beginning with job site layout and grade checking. We are now using machine control on dozers and excavators with impressive results. For the entire 10 years I??ve asked everyone I??ve met to explain the technology. No one has had all the answers. Many of the sources such as the dealers (the only way those of us in the field can interact with Topcon) have a basic presentation but that's all.
Treat machine guidance systems like an RTK system where the machine is the rover with a model of the planned construction. When the rtk reading meets the desired grading level on the model then the grading is complete. One thing you should always have is a QC/QA plan that includes calibrating the machine to make sure the grading is consistent with the model.
Thomas Taylor, post: 438100, member: 12899 wrote: Hello, New guy here to this site.
I'm and old retired licensed land surveyor in California where I spent a lot of my later working life at Caltrans working on implementing new technologies and conducting geodetic surveys and RTK surveys.
About 13 years ago I wrote a class of 12 modules for the local Operating Engineers' Apprentice Training Program for Surveyors. They have a license to use it but I retained the copyright.
I haven't done anything with them for awhile. So, if there is an interest I thought I would post them here for anyone to read.
Here is the first module........
Yes very interesting, please continue to post.
Mark Mayer, post: 438360, member: 424 wrote: That picture is an http://www.snopes.com/misaligned-bridge-photo/&apos ;">old thing that has been around for years. It isn't any particular bridge at all.
Thomas Taylor, post: 438361, member: 12899 wrote: Ha, Evan..... No, I got that from a presentation by Dave Doyle or Dr. Snay of NGS.
I did, however, work on the geodetic control for the Bay Bridge project and a bunch more in the SF Bay Area and all of them got built without the page 6 problem.
I should have used the sarcasm font. Just yanking your chain Tom. I've seen that picture before and don't recall if the first time was before or after the Bay bridge was regularly in the news for bad steel and negligent inspection. Based on what the news outlets were saying, seems like the surveying was the only thing to go right on that job.
Thomas Taylor, post: 438100, member: 12899 wrote: Hello, New guy here to this site.
I'm and old retired licensed land surveyor in California where I spent a lot of my later working life at Caltrans working on implementing new technologies and conducting geodetic surveys and RTK surveys.
About 13 years ago I wrote a class of 12 modules for the local Operating Engineers' Apprentice Training Program for Surveyors. They have a license to use it but I retained the copyright.
I haven't done anything with them for awhile. So, if there is an interest I thought I would post them here for anyone to read.
Here is the first module........
Thanks Thomas. I actually taught a RTK field class in 2002-2003 for local 12. They / I, really needed a training program like you put together. The training back then was based on how good the gps salesman was. People always bad mouth the unions, me included but the operating engineers had a darn good apprentice program and all that went through it had a good basic knowledge and were productive because of it. Thanks again, Jp
FYI,
I should make it clear that a lot of the information in the modules was compiled from information on line from NOAA and other resources. The pictures were downloaded from NGS and other stock web sites. I do not intend to misrepresent anything or to step on anyone's toes. The Geodesy Tree picture showing the relationship of geodesy to other disciplines was one of many on line pictures showing the exact same information. The site I got it from had a bunch of stock images and this one had no attribution.
Last night I received the following message:
7/24/2017 Thomas Taylor I just looked at RPLS (been under the weather for several days) and saw your post.
I got to page 3 (which is not numbered) and see you have a picture that shows the relationship of Geodesy to other
disciplines.
My question to you is; DID you get permission from Dr. Petr Vanicek ???
It states in his book where you got this from "Geodesy the Concepts, 2nd edition the following;
"All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in
any form or by any means, electronic. mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner."
The picture you show came from page 24 of above book.
After all you are trying to protect your work.
John Nolton
Yeesh.
So, I decided that separate threads for this topic doesn't work. I will now post all subsequent modules on this thread.
Here is the third module, Transformation and Mapping Projections.
As a point of reference, my approach to writing this was to establish a linear fundamental foundation of geodesy, an understanding of projections and transformations, to have a clear understanding of the basis of geodetic surveying utilizing global satellites, and to describe GNSS surveying guidelines and the collection of data and processing of it.
Use as you see fit. Or not.
eapls2708, post: 438353, member: 589 wrote: Good stuff Tom.
Is that picture on the top of p. 6 from the Bay Bridge project?
There is an actual bridge that ran into a similar problem. It was built between Germany and Switzerland, where Germany used the sea level at its north coast and Switzerland used Mediterranean Sea level.
A few typos:
Syene is Aswan, not Answan.
plum lines -> plumb lines
Some more characteristics of Lambert conformal conic:
If you set the standard parallel to 0?ø, or the two standard parallels to x?øN and x?øS, you get a Mercator projection.
If you set the standard parallel to 90?ø or -90?ø, you get a polar stereographic projection.
If you set one standard parallel to 90?ø and the other to something else, you get an error. I've done this on two different computers using the same code (the Bezitopo mentioned elsewhere), and got wildly different results.
And to round out the Geodesy portion of these pdfs I will skip the chapters dealing specifically with California, The CCS, and the step by step methods of calculation for projecting lat/long to a state plane coordinate and the reverse by using the polynomial coefficients method. If anyone wants those, send me a message and I will send it to you.
This module deals with vertical datums, orthometric heights, geoid heights, and ellipsoid heights.
The GPS modules will be uploaded to a new thread.
And to round out the Geodesy portion of these pdfs I will skip the chapters dealing specifically with California, The CCS, and the step by step methods of calculation for projecting lat/long to a state plane coordinate and the reverse by using the polynomial coefficients method. If anyone wants those, send me a message and I will send it to you.
This module deals with vertical datums, orthometric heights, geoid heights, and ellipsoid heights.
The GPS modules will be uploaded to a new thread.