Ive got close to 160 hours of full up from PLS taught vendor specific training in Bentley and Trimble, and can honestly say about 50% is stuff I already knew, but the stuff I did learn was esoteric to the hardware's and software and it's worth the money to not waste your time learning on the fly. some mistakes you're not going to be able to get fixed by getting a more knowledgeable person to work with it
they need to get you the proper training you deserve for taking this on.
period.
They better be willing to pay for every minute of training you need, as well as throw in a nice big pay bump for you taking this on.
Eh, I get your point, but there are times when the opportunity is there for the taking, and the extra dollar means less than the chance to expand your knowledge base, and make yourself vital to this company or the next
The vendor training will get you a jump start on the data collector and rover but usually doesn’t teach the math underlying concepts of satellite positioning and grid to ground. They assume you know all of that and here is what button you push to get to what you need. Every one here has stated very clearly what all is needed. I think if you get the training for underlying concepts down and how to get the software to do and be able to check what you want you will be fine. Its a firehose you will be going through. Geodesy for the layman is a good free download. NGS. On that site is also some free webinars that were pre recorded on datums and some basic geodessy as mentioned above. Grid to ground What state are you in? You can look up also on NGS site the publication of that states coordinate system so you will know if you are dealing with a Lambert Connical or transverse Mercator. Scale factor was mentioned but you also need ellipsoid factor then combined factor. Scale factor and ellipsoid or sometimes called elevation factor make the combined factor. These terms you need to understand. Geoid model as well. With gps or gnss you will need this understanding. Ellipsoid and geoid heights are not elevation. I think the support at carlson would be on my speed dial. They have some great support and good training presentations as well. Tap into that as soon as possible. Don’t let all of this scare you. You can learn it. Do lots of redundancy checks. Set some points measure them with total station until you get the feel of everything down. Know your difference of ellipsoid vs elevation height rough that will save you check with opus or known monuments. To make sure you are on datum. Depending on state know if you are a us survey foot vs international foot. On which datum. Nad83 nad27 etc. even some cities and counties withen a state have there own systems. Know ngvd29 vs navd 88 vertical datums. Look up PDOP VDOP GDOP. Terms for GPS rms precision values vs accuracy. Precision vs accuracy. You are coming in as things have changed dramatically in the Gnss world. You will see more satellites at any given time than they even had in the sky when i started. This site will be a tremendous help. Very knowledgeable people here. And all are willing to help. We are all learning together. Always.
There is a HUGE difference between using something almost every day and understanding EXACTLY what is happening and why. Your mentor needs to be someone competent, not necessarily someone who has a lot of experience but little knowledge.
We now have surveyors who are writing descriptions that will not agree with what they find already in place. The reason is as simple as assuming any State Plane coordinate is perfect to be used over and over for different projects that are not a part of the first project. We now have people not recovering existing monuments that were visited once some number of years in the past, as the thought is that there is no need to do so. In PLSSia this leads to moving coordinates from one section into controlling those in other sections, incorrectly.
We are also finding descriptions that are too long or too short on certain courses as one is written in grid and one is written in ground. Or some factor was applied to one but not the other.
The same firm may show record bearings that vary greatly from "new" bearings when following their own work from a few years earlier due to the difference between which "system" of North is involved,.
While it's nice to know something about how GNSS works, your immediate need it to be sure you understand the coordinate systems and projections involved. You should have had some exposure to this in class.
GNSS receivers do their calculations in earth-centered XYZ coordinates and the receiver or data collector can convert to other representations. To end up with ground distances, you will need to use either State Plane Coordinates, UTM, or a custom projection to get the numbers you need out of the hardware. If it isn't a custom Low Distortion Projection (a very useful tool) you must know how to convert from the plane projection to ground distances that are compatible with total station data.
Get that workflow going and then worry about how the GNSS works.
you must know how to convert from the plane projection to ground distances that are compatible with total station data.
An excellent point!
When the Push Button Was New, People Were Freaked - JSTOR Daily
“You press the button, we do the rest”
Don't be a button pusher!
User Guidelines for Single Base RTK Positioning Useful and free from the NGS. The USCOE publication that GeoddMike linked is also worth the price. Van Sickles GPS for Land Surveyors has been recommended and I strongly second that.
Many people treat their GPS units as little more than black box coordinate generators and, mostly, as long as you understand that and the limitations, it is an OK place to start. Just don't pretend that it is anything else until you understand it better. Everybody has to start somewhere.
@goodgps we will probably start out with the more basic option you laid out. It will be a base and rover from carlson and SurvPC.
@nate-the-surveyor We use Civil 3D for our drafting and Surveying. I setup all our templates when I got hired and have pretty much been running the CAD since. Before I got here they did all drafting in civil in the model space and never bothered to learn paper space. They used another program for years but I am not sure off the top of my head what it was.
GPS is easy.
Always, always be sure your basis of coordinates is good geographic data.
There is never a reason to skip using all the CORS, Vendor, OPUS, VRS calculations available to set up any job on good Lat, Long data.
Always project your coordinates to a grid that's definable, it may be State Coordinates, UTM, a user defined LDP.
My advice is to never, never calibrate, you will thank me as time progresses if you avoid that cluster of madness.
It may be that the company has lots of terrestrial data to merge the GPS with, rotate and translate the old data to the new projection whenever possible, don't hold the old data and try to make GPS conform to it (it's sold as the way to do it, but it's not).
And use a Geoid Model (the latest is the best) even if it means applying a correction to get on local control.
Really, GPS isn't all that difficult to use and understand, you won't need to do double differencing calculations.
My advice is to never, never calibrate, you will thank me as time progresses if you avoid that cluster of madness.
It may be that the company has lots of terrestrial data to merge the GPS with, rotate and translate the old data to the new projection whenever possible, don't hold the old data and try to make GPS conform to it (it's sold as the way to do it, but it's not).
And use a Geoid Model (the latest is the best) even if it means applying a correction to get on local control.
Some really good nuggets there
My advice is to never, never calibrate, you will thank me as time progresses if you avoid that cluster of madness.
It may be that the company has lots of terrestrial data to merge the GPS with, rotate and translate the old data to the new projection whenever possible, don't hold the old data and try to make GPS conform to it (it's sold as the way to do it, but it's not).
Best advice so far!!
My advice is to never, never calibrate, you will thank me as time progresses if you avoid that cluster of madness.
It may be that the company has lots of terrestrial data to merge the GPS with, rotate and translate the old data to the new projection whenever possible, don't hold the old data and try to make GPS conform to it (it's sold as the way to do it, but it's not).
That has been my long term policy as well.
Hmm, I'm going to get really picky here.
My advice is to never, never calibrate, you will thank me as time progresses if you avoid that cluster of madness.
...
And use a Geoid Model (the latest is the best) even if it means applying a correction to get on local control.
A calibration can be a way to apply a correction to get onto local control.
If you have a well-defined coordinate system, a single point calibration will give you position and orientation.
And it is easily checked in the field.
Around here our local control is based on ITRF2000 not WGS84 so this a common practice.
It does help to understand what is going on, and the implications, but calibration is just another tool in toolbox
YMMV
