Static Survey

> Hey guys! I'm pretty new to the profession and currently dont have anyone in my shop to show me how to do this. But Im trying to figure out how to setup for a static survey to layout a benchmark. I have a 5700 and a tsc2 to work with.

So, how are you using your 5700 presently to determine the elevations of things? If you aren't familiar with using GPS, you should turn the whole effort over to someone who is. If nobody in your "shop" is proficient with GPS, then it's going to be a rough ride any way you saddle up.

Tall order. I suggest using OPUS.

Think the "Wicked Jester" may be living up to his Name!

Lol, kinda figured these would be the responses I'm getting. Don't really want to "turn over" the GPS portion to someone else as I'm trying to learn it. Also we have no one to turn it over to except maybe a outside contractor...

Right now we don't use the 5700 as the guys before me said it was missing components.. which it isnt.

Also I'm working on getting a computer that is off network so that I can download from our tsc2. Yes I have to have a computer off network to he able to download something via Usb.

I've read through the user guide. It does explain fast static very well. But from my developing knowledge of GPS I wonder if it logs enough data to establish a control point or benchmark. Where I have the base setup it is able to receive from 9 sats. So probably over thinking it all but I thought I would try to reach out and learn more.

WJ,

You don't need the TSC2. Just turn on the 5700 and let it "cook" for a few hours. You can then download the two necessary files from the 5700 and send them to OPUS to give you a solution.

Pay no attention to Kent. He doesn't know much about GPS.

Dave

> Just turn on the 5700 and let it "cook" for a few hours.

Don't forget the blue button!

> You don't need the TSC2. Just turn on the 5700 and let it "cook" for a few hours. You can then download the two necessary files from the 5700 and send them to OPUS to give you a solution.

Excellent idea. That way you'll know the elevation of the base of the 5700. If you actually are interested in knowing the elevation of the benchmark (which will, of course, be limited by various factors, not the least of which is the quality of the geoid model), you'll need to accurately determine the height of the base of ARP of the unit above the ground mark.

The duration of the session should be at least four hours for a best quality OPUS static and six would be better. Two different days, adjusted by least squares, would be a minimum to improve the ellipsoid height obtained via OPUS and demonstrate that the uncertainty estimates generated by OPUS are not unrealistic.

The other issue is how important it is that the benchmark be integrated into the local leveling network. If that doesn't matter and the geoid model is known to be without significant problems, then OPUS is a good option.

:bad:
Fool's(Jester's) Errand

If you're going to send it to OPUS the blue button is not a bad option; I would hard boot the receiver first (about 40 seconds holding down the power button; when the satellite light comes on for 15 seconds and then goes back off it's finished). This will ensure that there are no boot files creating undesirable behavior and that the memory is clear.

If you use the TSC2 check the Fast Static survey style - in Base Options make sure the antenna information is correct and that you're logging at 15 (or 30) second intervals to the receiver. in Static Point options make SURE that none of the boxes are checked that would make the session stop after a fixed length of time. When you start the receiver start it as a base.

After the session(s) conclude you can transfer the file(s) to the TSC2 to download using the Receiver Files command under Instrument. Trimble has a free Convert to RINEX utility on their web site, download it and convert the T01 file(s) to RINEX and submit to OPUS.

NGS has plenty of info on their page as far as how to evaluate the quality of an OPUS solution, if you're willing to do some research you can learn everything you need to know to successfully accomplish what you want to do.

Just an advice.
If you are going to use it for static observations without using the DC for recording the station name & HI, then better not to forget to record the receiver number(a sticker to the side of the receiver is what I use)start time, end time for each station. Raw data from the receiver without using the DC will comeout with no clues as to the station it occupied so you will have to refer to your fieldnotes or you might be making a kind of guessing game at the office.
Oh and did I mention the HI? HI will be important if you need to refer to elevation values derived from GPS observations.

Again did I mention HI???

You might want to consider getting your hands on at least one other receiver and using the second to simaltaneously gather data on other known benchmarks with published values so you have some idea of how yours 'measures up' in the larger scheme of things. The HI and using the correct phase center antenna model will also be critical to obtaining good repeatable results.

RTK 1000 times then run a level loop to it.

Just a suggestion

Just a suggestion. Hire another surveyor, who is familiar with this whole game. INCLUDING the post process, geoid portion.

What you want for a final product is:

Elevation, as though somebody had 3 wire leveled it, with a closed loop, however, using GPS. That is your final goal.

You want an honest NUMBER, with a genuine error estimate. For elevation.

And, as a side benefit, go ahead and get the actual SPC for the site. And, learn a bit about combined scale factors, elipsoids, and the actual things that happen, to derive useful answers, using GPS. Stuff like US survey feet, and international survey feet. Go ahead with the error estimates for the horizontal too.

Get your money's worth. Don't be afraid to get rid of somebody that knows enough about it to do what you need for this job, BUT not enough to really teach you.

N

:good: