> Okay, then. You need at least three called for monuments to re-establish the bearing system. Got it.
No, you go ahead, and determine what you need, on your own.
Sounds like you either need someone to provide you a plan with SPC or something else, instead of tying into monuments, gathering evidence, and making an educated evaluation of the data, information, etc.
Have at it.
> > Okay, then. You need at least three called for monuments to re-establish the bearing system. Got it.
>
>
> No, you go ahead, and determine what you need, on your own.
>
> Sounds like you either need someone to provide you a plan with SPC or something else, instead of tying into monuments, gathering evidence, and making an educated evaluation of the data, information, etc.
>
> Have at it.
Hey, you're the one who proclaimed that if two called for monuments are found, then you've re-established the bearing system.
It would seem that if you found two called for monuments, that were on some arbitrary basis of bearings, i.e., oriented with some deed called bearing, then there wouldn't be an independent check on that bearing. It would require locating at least one more monument to be able to check the angular relationship between those monuments. If, however, the bearings had been oriented with an astro observation or GPS derived vectors, then you'd have at least one way to check the credibility of the monuments without having to rely on the things that constantly go missing...the actual physical monuments. Disregard monuments, never. Augmenting the monuments with an independent bearing system seems like a win, win, to me.
And you still seem to be under the misconception that SPCS = bearings.
I proclaim nothing in life.
I merely stated that reproducing bearings is as simple as locating monuments shown on a plan, and rotating your work onto them.
However many monuments depends on the situation. And if there aren't enough, then other methods have to be used.
What I can't believe is...
> Auspos supposed works world wide (and is most definitely free to use). Is there any similar things available over there?
As others have pointed out, the National Geodetic Survey's Online Positioning User Service (OPUS) is exceptionally useful. I use it on virtually every project, even those that aren't out in the boondocks. The accuracies typical from more than 4 hrs. of L1/L2 observations are better than about +/-5mm (s.e.) in N and E components.
A surveyor who is using L1/L2 GPS with the ability to log observations has free access to the national datum at what in many parts of the US is excellent accuracy.
you can't be this dense, JPH.
You ought to just stop now and think on this for a while. As these debates wind down, your team always takes the same predictable route. You do realize that the people doing solars and georeferencing their work still dig for monuments with a shovel and research adjoining deeds and senior lines, and hold monuments that they find, right? Surely you're not thinking we go to all of the effort to document reproducible bearings and coordinates on points that aren't seriously vetted as the best evidence of the boundaries, right? We're doing all of the stuff you're doing we're just taking it one step further.
I suspect a lot of the opposition clings to their stance out of fear of the apparent complexity involved in determining an bearing by celestial observation. I have incredible confidence in you, JPH, to be able to do them. I'm no rocket surgeon, I assure you. As in all things scientific, the proof is in the repeatability of a process. In this case, I'd challenge you to make an arbitrary baseline near your office, preferably several hundred feet in length with both ends in decent sun. Take a day and do a set of observations on one end of the line. Then go and do the same on the other end. How did they agree? Do it all again a few days later. Keep doing it until you feel confident in the mechanics of it all. The first time it'll take an hour or two. The second time it'll take half that, until pretty soon, you're doing a set in 15 minutes. At that point, once you've seen what you can do, start incorporating the procedure into your work - as you deem appropriate. Might not be every job. Might only be a few times a year. Then again, once you see how easy they are, you may find yourself doing them pretty regularly.
The point is, the objections just don't stack up. Fear leads us to irrational behavior (like defending an indefensible position). Face the fear.
One Example NOT Related to Reproducible Bearings
I went out to a piece of property down Yarmouth way. This is registered land so the location and title are guaranteed by the great State of Massachusetts.
Registered land is required to be tie into other land court property, as well as have monuments at least within 500' of other bounds.
Well this particular parcel, four sided, had concrete bounds at each of the corners. The original land court plan only showed interior angles and not a bearing on the plan.
Well, now, this didn't stop me at all. All bounds checked within hundredths' of each other for location so we staked the lines without reference to North, South or the moon.
I didn't bother to break out the GPS, or make a sun sight. All lines were less than 100' so it really would have been overkill to occupy a corner for a few hours in order to determine "GPS" north 🙂
I've done sun shots before and got pretty good at it. Kent's right, 20 minutes should cover it, depending on time of day and weather of course.
But I didn't need any of that for this little job.
Let's just consider, "The right tool for the job." My van is filled with surveying tools, but damn if I use everyone on every job!
Like one nefarious poster once said, "I could survey with a banjo if I had to," and I frequently do survey with a "Banjo" myself, since my dog is named Banjo 😉
Dtp
What I can't believe is...
One step forward would be to realize that the priority list for monuments, distances, bearings, coordinates, etc. was created based on what are now outdated relative accuracies/reliabilities.
Coordinates were last because, until GPS, in most instances it was entirely impractical to make them as accurate as distances. Now the distances are often measured by subtracting measured coordinates.
Any of those items should be evaluated in terms probable error and the rules should allow them to be re-ordered according to a realistic estimate of the standard errors of each. Undisturbed monuments still rule because they have no error. The rest (should) depend on how they were measured.
first example
> I think you are letting yourself get confused on the main point. There was no other evidence of those back corners of the twelve foot strip. Had there been we would have used it. We were left with occupation. This isn't about being an expert measurer it's about expertly using measurements to reconstruct a lost boundary. And yes absolutely if I knew the bearings were astronomic I would have staked by that with no other evidence available. Wouldn't you?
From what I know about the 12' strip that is 2000' long.....
I would locate the two pins 12' apart then convert the math of the deed (or plan) into coordinates. Then I would locate the physical evidence (i assume a road traveled way) and convert that to coordinates. Holding one of the pins, I would then rotate the physical evidence to see if it could fit entirely within the 12' deeded strip. If it fit nicely, I would calculate the sets and most likely set additional monumentation to avoid problems in the future.
If I had the additional information of a repeatable bearing base and it conflicted with the occupation, I would most likely assume the Bearing Base was incorrect. Unless there is evidence to the contrary, I would assume the traveled way would be the best evidence of the intent of the conveyance.
One Example NOT Related to Reproducible Bearings
> Well, now, this didn't stop me at all. All bounds checked within hundredths' of each other for location so we staked the lines without reference to North, South or the moon.
>
> I didn't bother to break out the GPS, or make a sun sight. All lines were less than 100' so it really would have been overkill to occupy a corner for a few hours in order to determine "GPS" north .
Just out of curiosity, how easily will you be able to re-establish the corners of that parcel if the concrete bounds are destroyed or displaced? For extra credit, what sort of GPS gear are you using that requires a few hours of occupation to solve a vector 100 ft or in length? Ten minutes of 5 second epochs would be more than adequate with my ancient Trimble equipment at that separation.
One Example NOT Related to Reproducible Bearings
The reproduction of the property lines shown on a land court plan will always be dependent on existing monuments from land court cases, so it will come down to the monuments recovered.
My GPS equipment is Sokkia gsr2700isx, if that means anything. Time of occupation for reduction is mostly an issue related to location. My geographical location is outside the standard polygon for CORS stations therefore longer occupation times are necessary.
Regardless, in my factious reply I was just pointing out that plenty of times reproducible bearing basis is unnecessary...not that it's a bad idea, just over kill on most of my jobs.
One Example NOT Related to Reproducible Bearings
> The reproduction of the property lines shown on a land court plan will always be dependent on existing monuments from land court cases, so it will come down to the monuments recovered.
That's fine but if you have records showing where such a monument was before it was destroyed, surely that would be the basis of a future boundary determination you'd make, wouldn't it? Or in Massachusetts, once a monument is destroyed is the idea that the corner must be re-established only from such evidence as still exists? Surely not.
> My GPS equipment is Sokkia , if that means anything. Time of occupation for reduction is mostly an issue related to location. My geographical location is outside the standard polygon for CORS stations therefore longer occupation times are necessary.
So, you don't have two receivers? One receiver is really not all that useful compared to what can be done with two or more.
> Regardless, in my factious reply I was just pointing out that plenty of times reproducible bearing basis is unnecessary...not that it's a bad idea, just over kill on most of my jobs.
Well, my idea is that one of the most important functions of land surveying is boundary maintenance. Every resurvey is a chance to build reliability by increasing the avaialble information, which includes determining the actual bearings of lines in a way that is independently reproducible.
Kent ??
> >
> Well, my idea is that one of the most important functions of land surveying is boundary maintenance. .
Kent, in a recent post, you criticized the practice of marking the property lines with blazes or intermediate monuments. What could be better boundary maintenance than keeping the lines marked? It's really quite easy to calculate offsets from the traverse stations to quickly and reliably mark a straight line.
Kent ??
> What could be better boundary maintenance than keeping the lines marked?
Well, a bunch of markers that aren't of record don't maintain anything when the boundary is defined by the monuments at the corners and runs straight between them. Maintaining boundaries means being able to determine where the corner monuments are or were and with reasonable certainty.
What I can't believe is...
oooo. good post, Bill.
Kent ??
Sounds like the work is easier in Texas.
first example
it wasn't a road. it ran generally perpendicularly from a highway. the occupation was a relatively new (maybe 20 years old) chain link fence - certainly not a 65 year old wire fence with lots of patina you'd want to hang a boundary on.
What I can't believe is...
I've often thought the same thing. The judges in the early cases that established the priority of monuments didn't just pull that out of their...lets say, robes. The decisions were based on presumptions (the inability to accurately reproduce locations on the ground given the technology, the fact that a lot of parcels were laid out on the ground first, then measurements to create the description were made from them, etc.) that are probable rebuttable in a lot of circumstances today. Especially in urban and suburban settings.
Kent ??
> Sounds like the work is easier in Texas.
I suppose it is in the sense that just because someone drives a piece of junk steel in the ground doesn't alter a boundary as one understands to always be the case in New Hampshire. Eventually, every boundary in New Hampshire sounds as if it will be essentially unsurveyable as more and more rebars and whatevers are driven into the ground by parties unknown and more and more trees get scrapes on their bark, all of which are apparently important boundary evidence. :>
Intent?
Was was the intent in creating a 20 foot wide parcel 2000 feet long? I would have bet money it was for access. What purpose did the chain link fence serve?
Kent ??
> Well, a bunch of markers that aren't of record don't maintain anything when the boundary is defined by the monuments at the corners and runs straight between them. Maintaining boundaries means being able to determine where the corner monuments are or were and with reasonable certainty.
I know it's a difficult concept to grasp Kent, but when the property lines are marked properly and accepted by the landowners for decades, these markers can be used (if necessary) to reset the corner monuments. If a georeferenced coordinate pair, (or a distant monument and a reproducible bearing) conflicts significantly with this evidence along the property line, then these coordinates become suspect. There are countless threads on these survey message boards of people screwing up coordinates so don;t tell me it never happens.
Even if the property line markers were installed sloppily, they will still lead you to the location of the corner. If nothing else, the marked property lines will give you a warm feeling when your pin set winds up it the intersection.
