In the Adirodacks our surveys have no open fields for RTK. Plus many large tracks have no cell coverage and poor UHF radio range due to hills, valleys and trees. If you need open sky around here, the best one can do is wait for a deep freeze to utilize lakes and swamps. Which we are lacking this year.
I disagree with your RTK suggestion. In my experience RTK will be more of crap shoot with a single vector than a static network solution using many vectors to the same point.?ÿ
I really appreciate this discussion hashing out these ideas. ?ÿI think you both (all) are making excellent and appropriate comments. ?ÿKeep them coming.
Some might say I am better off running my RTN rod up to ~15 feet to try to get a real time fix rather than try the static gps approach.
In the Adirdack surveys we have no open fields for RTK. Plus many large tracks have no cell coverage and poor UHF radio range due to hills, valleys and trees.
That is also very much the case in western Oregon and Washington. You get some GPS positions where you can and traverse the rest. But the OP is in Indiana.
Some might say I am better off running my RTN rod up to ~15 feet to try to get a real time fix rather than try the static gps approach.
I won??t say from personal experience that I know this works as I??ve never done it myself or been able to check the results in the office - but when I was much younger on a field crew, I remember a party chief doing this somehow with a 5/8-11 threaded dowel & the receiver on the top of a 25?? fiberglass grade rod. I remember thinking then that was a bad idea with all the flex/deflection at the joints in the rod haha. I wouldn??t recommend doing this with a loose rod though but I bet raising the receiver up higher on a rigid pole would be beneficial?ÿ
I've got a 25' Hixon pole, with special Hixon bipod. For this very purpose.
And, a 20' one. Now a days, I use. The 20' one to hold the base radio antenna, because it fell over, and got bent up a little.
N
Raising the antenna might be a miracle cure on a Christmas tree farm, but can you get enough height to benefit in mature forest?
Bill, I bought the tallest, and best I could buy. It became my final conclusion that for the most part, that 16' was as long of a pole as I really needed. Here in Arkansas, you can have 2 basic layers of trees. The 50' plus bunch, and the up to 15' group.
Now a days, 12' is as tall as I need. Usually, to get a roof corner.
It got cold last night. In the teens.
N
@nate-the-surveyor I have one of those 25ft Hixon poles with bipod. There is a lot of sway up at 25ft.
Works great for Wetland flag locations.
When collecting static data in challenging conditions (tree canopy, urban canyon, etc) more is better - more time and more occupations. It is also a good idea to assess your data using TEQC, as there will often be many cycle slips, which can be cleaned up before submitting to OPUS or post-processing on your own
https://www.unavco.org/software/data-processing/teqc/teqc.html
?ÿmany cycle slips, which can be cleaned up before submitting to OPUS or post-processing
Is there somewhere with a good discussion of how to do this?
Interested in learning this skill also.
Can you see evidence of a cycle slip in the rinex file?
Or how does it look in the graphs you get in post processing software?
The tutorial is somewhat comprehensive.
https://www.unavco.org/software/data-processing/teqc/doc/UNAVCO_Teqc_Tutorial.pdf
One of my staff just did this for some very noisy data collected near some large conifers on the grounds of the State Capitol in California. NGS initially rejected it (without the TEQC clean-up) but afterwards it was accepted through OPUS Projects for inclusion in the NSRS, although it hasn't been published yet (horizontal). Adjusting the elevation mask helped some also. The PID given from the recent (last summer) First Order leveling campaign is DR6931.
Of course you can leave a unit on a point then spend lots of time processing and removing portions of bad data, but why?
How big a deal is any point that you spend client's time and money doing static.
It's always been better to find out with RTK what you're up against and do what you can with it, if that means setting up the robot then that's what you do.
Going back out to traverse after spending all that time messing around with a static session and it doesn't work; that time should be eaten by the surveyor.
And how much time are we discussing, I often hear put the unit up for 4 hours minimum, seriously??ÿ
What are you doing for those 4 hours?
You have 4 corners in deep woods to set, what good it static??ÿ
Can't set them with it, so all you can do is locate something.?ÿ
What??ÿ
A point under a tree and you're going to static it for 4 hours?
Then what??ÿ
This is all interesting academically, but in the field it's always better to leave the site with good data, whatever it takes you to get it. And there are time constraints, putting up a bunch of receivers and "letting them cook" is expensive, who pays??ÿ
Charge for 4 hours of receivers - 16 hours of GPS=$xxx
Charge for setting up 4 receivers=$xxx
Charge for processing 4 static sessions=$xxx
Charge for going out again and traversing into the 4 points=original $xxxx/2
lost revenue=original $xxxx.?ÿ
?ÿ
The sole purpose of the survey I mentioned was to do what was required to process in OPUS Projects and get the geometric position accepted by NGS (bluebooked) to couple with the First Order Class I vertical position established last summer. If you look at the location of the mark in NGS Data Explorer, it was not set "under a tree" but in a concrete mass with as open of sky as possible considering the location.?ÿ
@spmpls?ÿ
These posts can get off-track sometimes. I wasn't replying to your post, although I can see that it looks that way. I'm more referencing Brad's OP and using static in boundary location workflow. My position is to use RTK till you can't, pull out the robot, supplement with PPK or static when it fits into time constraints, but not to rely on static, it can bite you if you do.?ÿ
During reconn of large 100 acres plus tracts I setup my base with 4 constellations in wide open sky as I can find running static and RTK simultaneously. As I do reconn I will try RTK for a few minutes if suitable,?ÿ else I will drop a static receiver on the point and move on to the next one. Since I have 8 recievers this is quite effective while using an ATV or a few helpers. Once all 8 units are set I will wait 30 to 60 minutes, doing comps or lunch. Then head back to collect the gear and back to the office. Not really much down time, or wasted time as noted here by others.
@leegreen question: ?ÿon that open sky base, do you quick grab an RTN coordinate on that point as well before you start cooking on it as a static base?
If cell coverage is good, yes I will take a few minutes to collect coordinates with VRS or RTN. Then use this to start RTK. I will also check this against OPUS, DPOS or post process myself to utilize GNSS. OPUS is still using GPS, only one constellation.?ÿ
