Is their a way to operate a survey grade GPS without a base (RTK) and get submeter points like a GIS unit. Can I take say a single Trimble R8 (or 4700) without a Base or VRS and collect sub meter data?
WAAS is supposedly sub-meter... maybe. You don't want to do any post processing yourself, right?
No base to post process from. Maybe could use a CORS, but how far out from the CORS could you be? I tried PPK once and had a bad experience but it was better than sub meter and I needed as good as RTK. I had to go back and redo 4 hours work.
> Is their a way to operate a survey grade GPS without a base (RTK) and get submeter points like a GIS unit. Can I take say a single Trimble R8 (or 4700) without a Base or VRS and collect sub meter data?
Sure, just process your rover data as a code phase solution using the nearest CORS. It works fine in GPSurvey, so there is bound to be a similar option in TGO. To paraphrase A.C. Mulford (who probably had never been to Utah):
>It is far more important to have faulty measurements on the place where the fence truly exists, than an accurate measurement where there is no fence at all.
Sub Kent in America
Sorry Kent, not boundary work. Asking for a friend working for fiber optic design firm. Apparently the engineers are good with sub-meter and don't want the extra expense for RTK accuracy. They don't have sub-meter equipment, trying to save a few bucks.
As far as the fences go it doesn't surprise me you are trying to make derogatory hay in an unrelated thread.
Ponder this though. What if the record is clearly not actuate in the measurements, has no calls to any corner markers, the GLO corner posts and mounds haven't been seen since about 1860 and about the only evidence on the ground is fences which appear to have the right pattern and have been respected as the boundaries for 50 to 100 years. Are the fences evidence that should even be considered in a land survey? The other choice is to just start making things up, turn sleeping chaos into a biggest cluster imaginable.
Also, how do you measure to within 0.01 feet and crank the least squares if there is no marker at all (not on the ground or in the record)? What do you hunt for? Maybe pick the nearest pebble or something? What if the wind or water moves it before the next guy comes along (tap it back with the vise grips)?
I imagine you don't need to contemplate such things in Utopia, eh?
And about laugh's, I'm amused at the derogatory comments you make against folks that do all day long presentations at national survey conferences and state conventions all over America. From what I hear you don't even attend such events (let alone present) yet put yourself up as the greatest land surveyor in America (safely in cyberspace). YEAH, that makes me LAUGH OUT LOUD!!
What do you do? Volunteer to teach third grade math? Maybe protest boundary law in front of the supreme court?
Yeah, you've posted more and said less substance than about any surveyor on the planet.
Sub-meter Engineers
> Sorry Kent, not boundary work. Asking for a friend working for fiber optic design firm. Apparently the engineers are good with sub-meter and don't want the extra expense for RTK accuracy. They don't have sub-meter equipment, trying to save a few bucks.
Well, the engineers have *survey-grade* GPS but can't figure out how to get sub-meter results with it. Is that the idea? The solution is still the same even if it isn't you out mapping fences with it. That's great that you're helping them figure out how to just scab something in there without having to go to the enormous expense of actually having to pay a surveyor. That's what I call civic-minded!
Sub-meter Engineers
Surveyor has single receiver that works on the state VRS. Going out of town where there is no VRS. Asked me, but I've never done the sub meter thing. Just trying to help a friend get what he needs.
So if you were going to plow 50 miles of fiber optic out through the middle of nowhere why would you need centimeter accuracy tweaked by a least squares? Sometimes your mouth in the speaking for others to put them down mode gets so far out ahead of your over blown ego that it's amazing you can talk at all.
Everyone’s ignorant until they ask the questions and seek the answers. Did you ever ask any questions or did you just start answering at birth?
OPUS-RS works pretty good. It takes a minimum of 15 minutes L1/L2 occupation per point, but reliably (at least for me) acheives much better than just plain sub-meter results.
Sub-meter Engineers
> So if you were going to plow 50 miles of fiber optic out through the middle of nowhere why would you need centimeter accuracy tweaked by a least squares?
Well, usually you would want the fiber optic cable to end up where it was supposed to and to have a pretty good as-built of it. Cables in highways and rail rights-of-way aren't exactly supposed to be eyeballed in if they have an assigned alignment in the right-of-way.
Sub-meter Engineers
> So if you were going to plow 50 miles of fiber optic out through the middle of nowhere why would you need centimeter accuracy tweaked by a least squares?
I think that must be the same theory that the pipeline surveyor I've had to follow all over South Florida must use. "It's Just Cow Pasture, within a foot or five is close enough. The intersection of those two fences over there must be the section corner, because it's a fence corner".
All was fine and dandy with his paper easements recorded at the courthouse until I had to map those easement legal descriptions when the rancher sold his property, and what do you know... I started finding gaps in the easements where one description coming from one section corner didn't come close to abutting one that started at a different section corner a mile or two away. I'm sure there was a pipeline burried there, but that's all I could be certain of...
I've surveyed long enough to realize that your "middle of nowhere" is usually someone's backyard, and the land owner cares as much about the accuracy of where you are locating something as the guy with a 75'x100' residential lot does.
Sub-meter Engineers
I don't always agree with how they built America. I know guys that plow fiber. I've complained about how they are there first and screw up the whole right-of-way for the next guys doing water sewer, what ever. Ever followed a cable and then it swings out into the road and then back near the fence. We'll this is how it happened. As they plowed there was something parked in the ROW. They just went around it to save time.
Also there is intent for an easement that it crosses the property, most times it will say that but no matter. If the record distance is short there isn't a gap, just a bad record distance. If all else fails, most of the time the utility has been there so long that the physical location must be taken into consideration. It's called prescriptive use and there is hundreds of miles of communication lines with easements derived from prescriptive use. If you don't believe that just tell your clients to tear it up in the gap and see what happens.
America can't move forward because of all this nit picky stupid stuff. You can't build anything anymore because it's impossible to make it perfect. Let's just make a cluster out of every little thing, yeah that will get it done.
I think what they want to do is locate a marked cable every 50 feet within a couple feet or so doing several miles per day rather than a few corners per hour.
> I think what they want to do is locate a marked cable every 50 feet within a couple feet or so doing several miles per day rather than a few corners per hour.
This might be an option for you. As I understand it you need to establish a point with a good coordinate every 5 miles or so. You set the backpack down on the known point at the start of the day, and every time you pass another known point. Supposedly your entire route in between can be located to sub-meter accuracy after post processing.
http://www.zupt.com/b-pins-land-survey.html
What about the Trimble GeoXH
Don't know if they make it anymore.
I'd say it's certainly possible if the units store code and if your software can process code only solutions. As to using the CORS for code based solutions then code is remarkably immune to the things we have problems with using L1 only for long base line centimeter solutions. I'd say you could easily use stations over 200 miles away and not have much degradation in the results.
With all the birds then I would think, given enough time on point, maybe 60 epochs then you could probably get reliable results in the one foot range. But make sure you can also log stats to check for outliers. You will find some but not many but this is the only way, other than to rely on visual checking the alignment on a map after exporting points.
That said then I would still advise them to purchase or rent a true unit made for this job. It and the math inside will be tuned better to achieve reliable sub-meter results in less time and also with much less weight.
Sub-meter Engineers
".....the engineers are good with sub-meter and don't want the extra expense for RTK accuracy. They don't have sub-meter equipment, trying to save a few bucks."
"America can't move forward because of all this nit picky stupid stuff. You can't build anything anymore because it's impossible to make it perfect. Let's just make a cluster out of every little thing, yeah that will get it done."
While it's fine to cut costs, isn't it better to do the project right the first time? Or do you just want to postpone the "cluster" until later on?
Considering the cost of repairing a fiber optic cable, I'd think the owner would want to know where it is as closely as possible.
In addition, if surveyors are going to branch out from boundary work into other forms of income-producing work (i.e., layout, scanning, etc., etc.) there has to be a recognition that the "expert measurers" are the people who should be doing it.
Folks on here complain about various portions of geospacial work being taken from the surveyor.....here's another example.
Sub-meter Engineers
I would just say that much of this sort of work has never been done by surveyors but by staff at the utility companies using whatever tools were available to them. I've trained people from Arkla and many other companies that wanted to upgrade their tools to better aid them in asset management. None of the people were surveyors but just professionals that needed to learn new tools to aid in their already ongoing work.
GPS is now the tool for them to better manage their infrastructure. Often it has nothing to do with writing easements or such but locating lines on poor maps more accurately so they can upgrade their AM/FM programs.
Fiber is part of the telephone industry and often has blanket grants where ever they decide to build lines and establish more coverage. We don't have an easement one in Lawton and in the rural areas they are often blanket easements. "A line crossing the SE/4 of Section....." No dimensions and no maps other than the ones the company itself decides to build to manage their lines.
Deral
I tried PPK once and had a bad experience but it was better than sub meter and I needed as good as RTK. I had to go back and redo 4 hours work.
If you've only tried PPK once with Trimble there may be a couple of things that might help. I've also had frustrations with PPK or Infill which is really the same thing. I've found that the longer you let the antenna see the sky during a fixed session the better all the data will be. If you just need one location, then you have to get into the truck and drive 3 miles to the next point and lose lock, then longer observation times at each point (probably 2 min. after fixing) works best. If you are in a smaller area and are taking a number of shots then shorter times (15 sec.) on each point with a long total fixed time works well. There is a default in Trimble processing that requires 120 seconds before it will process a PPK. I turn it down to 5 sec. each time I update the program and that allows me to control times in the field. One of the Trimble trainers told me he sets the base to collect data at one second intervals which allows him to collect field PPK or Infill shots with three second times. I have not had success with those kind of locations.
Also, you can force the program to process the points. If you can, it might be interesting to go back and look at the PPK you did, compared to the results when you had to return to the site. Turn down the minimum observation time and they might process. Or, by "forcing" the program to calculate the baselines (check the blank box on the slide when it tells you that the solution doesn't look great) they often will actually be good solutions. Not that you should depend on such a calculation, but it can be a good check.
It works best if your base is near (10 miles) but you can push it farther. If you have a 5800 I don't think you'll get something better to locate accurate points without a radio connection.
I agree with you Deral! I prefer to static for 2 hours for opus. Using gis equipment for laying fiber will not work! I use TDS Hyper + for all aspects of the job, and when in doubt use the total station. Sorry for the format of this message in the field, I'm in Wichita Falls, Tx and sometimes you have no choose in using fences as a boundry ie has only been surveyed one in 150 years.
Leon
Yes, but you must first set up a survey style for that under configuration. Then use the rover as you normally would, but your corrections are coming from the waas.
If you have pathfinder then you can process against CORS stations. I've done it (it's really fast too) and found that my waas solutions became decimeter solutions on known points.
We were mapping rivers and creeks as boundaries with out submeter until it died and now we use the rover on the r8.
Good luck, you'll love it.