You set a point in a field somewhere and record its position by gps with survey grade
equipment using all the latest technology and data.
How would you publish the coordinates and how close do you think another surveyor
with comparable equipment would come to locating it
Full metadata / Bang on
Tomorrow - centimeter or two
10 years - depends on quality of meta-data and appropriate corections, but probably decimeter
100 years - assuming something like GPS still exists - meter.
If you have it set up for 4 hours use OPUS Publish. Your position will be sub centmeter. Anyone will be able to find it.
What Is This Point Made Of? And How Big?
If the point is plastic, only the best will find it. If it is larger or ferrous the recovery crowd grows larger.
Paul in PA
N and E with datum. coupla reference ties.
is this a real question?- if so, seems like a tree/forest kinda thing. i mean, i've been doing this long enough to have bird-dogged plenty of old boundary and traverse using nothing more than two-taping (more often than not, just an ability to read a survey and an inherent understanding of visual cues does the trick). i don't know why the above would be any less sufficient than it ever has been. if that's not enough info, then the guy trying to find it needs some more experience, imo.
Assuming proper metadata and that NGS is funded and CORS or replacement technology continues to be supported, why would it degrade in 10 or 100 years?
Continental drift data will be kept so that HTDP or similar tools should correct that the centimeter range, and I don't see any other major factor.
Short Version:
REF FRAME: IGS08 (EPOCH:2013.7997)
X: -1,657,562.988(m) 0.004(m_P-P)
Y: -4,744,797.228(m) 0.007(m_P-P)
Z: 3,917,223.070(m) 0.003(m_P-P)
Long Version...well...LONGER!
Maybe just use the OPUS_Static Extended Output Report, that should tell most folks enough to get a pretty good feel for the POSITION and reliability thereof.
A Least Squares Adjustment Report, might work, but the OPUS_Static Extended Output actually tells you MORE about the solution, and contains all of the requisite information to solve a Least Squares Adjustment of a SINGLE Occupation solution (which is what we are talking about ).
The Extended Output Report also returns the HTDP derived "shifts" between NAD83 (de jour) and IGSxx (de jour), as of THAT DATE.
2-bits
Loyal
My Trimble guy said when he does training he hides a dime in the field and takes a shot on it. He the. Gives the coords to the student and they key it in and navigate to it.
All you need are the coordinates and the datum and you can navigate to anything.
Then along comes a big ole earthquake (or two thousand)
The earth moves and takes the dime along with it.
Has the point moved?
Did ya ever wonder?
We are standing on a ball of molten lava whose surface has cooled to a point where human life can be sustained. Our tectonic plates drift and move around, and we have a coordinate system fixed to something that does not move. However, our earth is an oblate spheroid that spins and wobbles, and rotates around our sun which is spinning around the Milky Way galaxy that is traveling through space. The more gravimetric data we obtain, the better our geoid gets. The plumb direction does not point to the center of earth. A point's physical location now depends on a fourth dimension which is time.
Our day is not quite a day, so we have to lose one every four years. Albert Einstein's Theory of Relativity says that even time can be changed. If the tectonic plates shift along a fault line spanning a section line, does the section line and corner move? It's physical location is where the original surveyor set it. GPS says that it did not move, but it is suddenly over there now.
Has anybody found my prism pole or that dime that fella lost?
So, when/where is Star Date 0.0.0?
I love surveying! Enjoy the weekend, and Monday is a new day! B-)
You are right but I could not tell if the OP was wanting some in depth technical answer and the issues in finding something years or decades from now or if he wanted to get some coordinates and give them to a buddy so he could find something next week.
True for most of us living near the centre of tectonic plates Bill, not so easy for the Japanese:
https://www.fig.net/pub/fig2012/papers/ts03k/TS03K_nagayama_inaba_et_al_5791.pdf
"Osika station, close to the epicenter of the main shock, moved 5.3 m eastward and
subsided 1.2 m"
i read "find a point" as in going out on a job and doing the initial recovery, as opposed to ensuring the next whoever that comes along feels obligated to go rent a topcon hiper+ and install microstation (when he runs leica and civil3D) and replicate your procedures and adjustments precisely. do i have some inherent problem with publishing a novel's worth of metadata on your traverse points? no, but i honestly don't see the point in it, if you're talking in terms of guessing who might come along down the road, and what their equipment, training, and/or procedures might be.
at some level this is going down that worn out road of numbers vs. knowledge. i don't see it as my job to ensure that the next guy gets the exact same readout on his post-adjustment window. that's nigh impossible in any practical sense anyways. and if i have done my job properly then it only reinforces what i said above- simple coords, datum, and a couple reference ties should do the trick- unless our goal is to dumb down the profession to the extent that field crews are interchangeable with your average mcdonald's cashier (something that's already too close to reality in a lot of larger companies around here).
of course, i could be misinterpreting "find a point." doesn't change much, though.
> You set a point in a field somewhere and record its position by gps with survey grade
> equipment using all the latest technology and data.
> How would you publish the coordinates and how close do you think another surveyor
> with comparable equipment would come to locating it
Uh, well, if you did it right the first time, and you publish what realization of the datum you're on and how you got there, then in theory, you should be able to, for the next forseeable future, be able to find it within the tolerances of what it was set with. The fact that the earth moves and the data gets a new realization date doesn't preclude one from working in an earlier realization.