thank you dallas for your reply..here is the deal..the location is not on any deeds, papers, not near property boundaries..its not going to be merely rerunning old property lines...the location is very well within the property lines..the only boundary i am worried about is the one created by this set of coordinates...yes i am looking for a location, and the boundary that encompasses that location...no research will locate the point...it will have to be marked {if even possible} either by electronics that are capable {if there are any} or by a professional that knows the well respected in my book anyway, art of surveying..the info on this project provided us with several sets of coordinates to work with....we did our best at locating these points via gps, delorme mapping programs, aerial pics, taking measurements off known points and then measuring along lines of bearing..we are not surveyors, and these locations were all located mostly by trial and error, and a whole lot of walking/measuring/mapwork..i could get us in the very close vicinity of each location...then we performed excavations, sometimes over pretty big areas, to eventually locate exact point, which has always been marked by original surveyors but always with rock instead of metal..at several of these locations it was no trouble..at our last one, there were areas very close that once an area outside of intended excavation point {intended by original surveyors} was breached, we forever afterwards were besieged by planned problems built to very seriously hinder anyone excavating in the area..anyway, at this point {the one i am working now} i have much info and warnings of what will happen if an excavation on this exact set of coordinates goes outside the intended dig area, which is the area within the lines of 00.00.000n//00.00.000w....say i am looking for 65.65.655 N and the same numbers W..a deviance up or down on the last numbers 655, will result in the end of the project, or game as we have decided to call it over the years...going up to 656, or down to 654, from 655 will result in major unrecoverable catastrophe...this point, {and the others} was marked a long time ago by the best in the business..they would have gone to whatever lengths necessary to ensure perfection as to the locations point, as it would have to be relocated exactly.....they did it in a way that only a professional, master surveyor of 140 years ago could locate it, excavate it, and do it without going outside the prescribed area to accomplish it....oh i can also add that these same surveyors also laid out a 40+ acre plot very nearby, that has many exact points marked on a survey map if that might help...it is kind of a history project, and treasure hunt, and kind of an archeological dig...if we can finish the project it will be one of those things that rewrites history..i can say no more at the moment due to confidentiality issues..a couple of the project members are very old and in bad health...i am trying to ensure we finish the project before it finishes them...and i appreciate any and all serious assistance that can be provided...
While I believe that that has happened on here, I think in this case the poster just has some very bad information as to how good surveyors were 140 years, and some very bad/confusing understanding of the different datums and errors that are possible. There's a whole lot of "knows just enough to be dangerous" thrown in for fun too.
I smell a troll
What you are asking
How can I find a top notch surveyor who can guarantee his ground point marks your given paper point. This sounds like quite a challenge to me. You have coordinates that are 140 years old? You want someone to use modern technology to hit coordinates that are 140 years old? You also need a guarantee so that ups the ante.
Can you at least tell us in what country you are located? And are these coordinates using the third dimension (ie elevation)?
It sounds like your "dig site" was established using celestial bodies to establish a point on the earth and boobie traps are in place like Oak Island. If the excavation isn't precise, the treasure room is flooded with sea water and the Holy Grail is lost forever.
Thant being said, whomever you recruit to retrace the evidence will need to know the means from which the coordinates were derived.
Were the coordinates referenced on survey map of the nearby 40 acre tract? If so, I would start there.
not a prank bill..i can only say so much at the moment..i can say that national geographic and the bbc have shown interest in our little project..i do know delorme isnt correct...neither is any gps i have used no matter the cost, yet i see several surveyors post here that its a simple push of the button on a gps...not so from what ive seen.., been there, tried that, and have been from a few feet to 1/4th mile off on any given day..once used 2 gps on the same spot at the same time and got 2 different sets of coordinates..there is canopy which im sure doesnt help too...i have taken the provided coordinates, and put them in to everything i can come up with,{gps/delorme/maptech/google earth/aerial photos/maps/usgs topos/etc.. mark all the different points {many} i come up with {with a single set of coordinates} on an aerial photo, then take measurements and lines of bearing off of visible objects in the photo, to the marked points, and then go out in the field, measure along these lines to get to my endpoint where only excavations will prove if i am correct..so far i am 8 for 9, as one coordinate was only used as a point and wasnt to have been dug..i can get in close enough to dig around and find the exact point but on this last set of coordinates that will result in the complete failure of everything..there is a property nearby these people surveyed...it has many exact points marked on the original survey map..i have a copy..the coordinates we have been working with have all been derived from a set of documents..every location we have excavated {correctly} has been within the confines of a property less than 25 acres in size...
not a prank bill..i can only say so much at the moment..i can say that national geographic and the bbc have shown interest in our little project..i do know delorme isnt correct...neither is any gps i have used no matter the cost, yet i see several surveyors post here that its a simple push of the button on a gps...not so from what ive seen.., been there, tried that, and have been from a few feet to 1/4th mile off on any given day..once used 2 gps on the same spot at the same time and got 2 different sets of coordinates..there is canopy which im sure doesnt help too...i have taken the provided coordinates, and put them in to everything i can come up with,{gps/delorme/maptech/google earth/aerial photos/maps/usgs topos/etc.. mark all the different points {many} i come up with {with a single set of coordinates} on an aerial photo, then take measurements and lines of bearing off of visible objects in the photo, to the marked points, and then go out in the field, measure along these lines to get to my endpoint where only excavations will prove if i am correct..so far i am 8 for 9, as one coordinate was only used as a point and wasnt to have been dug..i can get in close enough to dig around and find the exact point but on this last set of coordinates that will result in the complete failure of everything..there is a property nearby these people surveyed...it has many exact points marked on the original survey map..i have a copy..the coordinates we have been working with have all been derived from a set of documents..every location we have excavated {correctly} has been within the confines of a property less than 25 acres in size...
I know the answer!
This is a very interesting discussion. Delorme, or any map projection isn't going to render itself to "ground" without a model. The earth is curved, any "map" is a projection from a curved surface to a flat one. No map is ever correct. As far as replicating positions, that is best left to a survey professional, not a layman with a GPS receiver. If you have distances and bearings, that is going to provide the best solution. Provided those distances aren't miles in length, and there is a reference angle with which to begin.
I can wholly replicate a position with our GNSS receivers, based on various methods of positioning. Replicating a position that I know little on how it was obtained, that is inherently unsolvable.
~Raybies
I'm with the gang of "hire a professional surveyor" to solve your seeming problem. I'll add one comment though that you mentioned above wherein you "told the surveyor.... bla bla bla" and thought $1K was too much money. Don't do that, we don't like that. Most of us tend to walk away from those folks, at least I do.
Let them do their job, take the liability, and pay them accordingly. My guess is that 140 yr old survey is more accurate in the property location. Precision is over rated these days because it really doesn't mean squat. Gives some folks warm & fuzzies, but what's the end result. The point is where it is.
I did a job 20 or so yrs ago for an FAA requirement project that effected some cell towers, antenna's and other features on top of 3 or 4 different 20 or so story buildings. I had a geometric nightmare on my hands working in a down town area (me & Mr Robot) doubling, triple shooting tops of things from different traverse points. I had to re-learn trigonometry with that one. Access to the roofs was out of the question, because the short answer was a long rope to hang over the edge, measure the dang tower with my Lufkin. Turns out the FAA had their collective heads twixt thyne buttocks, and my guy was right and the city had records to prove it so. Sweated bullets on that one though, but at the end of the day the tower is where it is and the planes could still fly over without crashing into them, per my measurements. And the city records were really close to being spot on. That research is critical.
Just a long winded silly geezer story (sorry leggers). Some can laugh, some can say "yup, been there, done that". I still like the rope idea myself, but instead I got paid lots more than a spool of calibrated rope would cost. Lots of ways to skin that cat....;-)
A novice with a GPS devise is like a toddler with a loaded revolver.
considering your knowledge of mapping, documents, and GPS it is amazing you have had this much success.
many surveyors use GPS daily and never really get it and struggle with getting close to the same point on another day... not bad surveyors, but not "skilled"
Now is the time for you to step back and have a professional help. You really should be asking for help in selecting the right person for the job.
PS: you should be able to get within one inch of any location and repeat that over and over again. BUT that takes practice, and skill, and Good Equipment.
> A novice with a GPS devise is like a toddler with a loaded revolver.
Or in my neck of the woods, a 9 yr old with an Uzi and can't handle the recoil so shoots the instructor in the head as the fully automatic got out of control. Opps. Didn't mean to kill you at this licensed shooting range. No charges pending, yet. (off topic but a tragic event nonetheless about 45 miles from me)
I just didn't want to get personal with the guy. Legitimate question from somebody who doesn't quite understand things. But I like your parallel, yet I remain civil. (or try to...lol) 😉 Then again, some folks just go fishing and maybe this is just another one. dunno
As others have said you need a local, knowledgeable surveyor and price should NOT be a factor. Give them the whole story and they will let you know how best to approach the project. You may be asking the impossible. Or you may just need a good surveyor. I could review the project for you and determine if what you are asking is even possible, There is a minimum charge and hourly rate that applies to my time.
> not a prank bill..i can only say so much at the moment..i can say that national geographic and the bbc have shown interest in our little project..i do know delorme isnt correct...neither is any gps i have used no matter the cost, yet i see several surveyors post here that its a simple push of the button on a gps...not so from what ive seen.., been there, tried that, and have been from a few feet to 1/4th mile off on any given day..once used 2 gps on the same spot at the same time and got 2 different sets of coordinates..there is canopy which im sure doesnt help too...i have taken the provided coordinates, and put them in to everything i can come up with,{gps/delorme/maptech/google earth/aerial photos/maps/usgs topos/etc.. mark all the different points {many} i come up with {with a single set of coordinates} on an aerial photo, then take measurements and lines of bearing off of visible objects in the photo, to the marked points, and then go out in the field, measure along these lines to get to my endpoint where only excavations will prove if i am correct..so far i am 8 for 9, as one coordinate was only used as a point and wasnt to have been dug..i can get in close enough to dig around and find the exact point but on this last set of coordinates that will result in the complete failure of everything..there is a property nearby these people surveyed...it has many exact points marked on the original survey map..i have a copy..the coordinates we have been working with have all been derived from a set of documents..every location we have excavated {correctly} has been within the confines of a property less than 25 acres in size...
I make a stab at it. I am not a surveyor but I use RTK GPS every day. It is very easy for me to survey a point and go back to it later and be within an inch.
This is not Delorme GPS this a a system that cost around 30k.
A handheld GPS like you buy at a sporting good store should get you within 10' most the time. Under some conditions the accuracy is worse than that but never 1/4 mile off.
I think your problem is a datum issue. Lattitude and Longitude are not just simple numbers like a pound or a foot or whatever. There are different datums from which lattitude and longitude are determined that have evolved over time as our technology and ability to understand the shape of the earth has progressed.
If you are using the same datums it is fairly easy to go to a point given a lat/lon using GPS. If you are using different datum you can be hundreds of feet off.
If you have points that you have found, GPS can be used on those to figure out an adjustment or correction to apply to the coordinates of the last point you are looking for. This would actually be fairly easy for a surveyor that is familiar with a three dimensional world.
Just to get a better understanding of what you have to work with, without giving away your location, is the coordinates in degrees minutes seconds.decimal
In the example you gave in a post above, 65.65.655 N, there are only 60 seconds in a minute and 60 minutes in a degree. That number doesn't make sense to a surveyor.
If you would give us just the latitude, put xx in the degrees, so we can see what format it is in and what precision you have to work with, we may be able to help a little more.
The formats usually used for recreational GPS are:
Degree and decimal of a degree DD.dddd
Degree Minute and decimal of a minute DD MM.mmm
Degree Minute Second and decimal of a second DD MM SS.ss
Mixing these up can get you off by miles. OPUS results are given to 5 decimal places of a second to get survey grade accuracy. Three decimal places of a second would get you to about a foot.
James
Coordinates are just a tool my friend, not the means to an end. In the hands of someone with the right skill set and the relevant metadata, practical and useful results can be accomplished. In the hands of a novice, the tool is very limited in it's potential. So far you've shared little in the way of useful information to allow anyone here to be of any real assistance.
As others have said repeatedly, electronics is quite capable of locating a point that was accurately placed in a known modern system of measurements. But any numbers from 140 years ago cannot be expected to work in a GPS to accurately find an old point. There is a lot of translation needed and original inaccuracies.
If the original numbers were 140-year old latitude and longitude, they were probably astronomical values, which are routinely hundreds of feet from where GPS would put those same numbers. And experts with the best field instruments of that era re-measuring those numbers astronomically might have disagreed by tens of feet at best.
However, surveyors of 140 years ago did not record positions in the format 65.65.655 N. You must have made up those numbers as a (bad) example. I can't figure out ANY format that would have 65 in the middle position. I could take 12.34.567 to mean 12 degrees 34.567 minutes, or perhaps 12 degrees, 34 minutes, and 56.7 seconds. In either case, a least digit change in latitude or longitude represents several feet. Old measurements of latitude and longitude are not going to be that accurate in absolute position, although a set of such numbers might approach that relative to each other, depending on how they were originally derived.
If you have some known points on the ground with numbers in the old coordinate system, the proper approach to find others in that same system is to re-measure the known points with great accuracy in some modern system, fit the old numbers to the new measurements by shifting, scaling, and rotating as needed for a best (e.g. least squares) fit. Then apply that same transformation to the values for the points to be found. That gets values in the modern system that can be accurately laid out on the ground, to whatever RELATIVE accuracy the originals were measured.
while i am planning on hiring a professional surveyor as stated well above, i am first interested in seeing if its even possible for one to do what i need done...i did do a post relating my and my neighbors experiences with local surveyors, and the costs associated..i never said a word to him or about him regarding his price...i paid him the minute he was finished..my intent in posting about it is here i got several saying hire a professional surveyor..so out of 2 local, *professional* surveyors..one spends 3 weeks in the deeds office researching a 2 acre property that only has a total of 4 deeds in all, then a while hunting property stakes i could have shown him in a minute or two, for a grand...then i got the second
*professional* that completely surveys a much larger property, that is actually a conglomeration of several parts of several properties that have been owned by many, cut up, sold off,and plots it all on a map, in a single day for much less....so, i guess the next question is, what is the meaning of professional in the survey world ?..im not kicking anyone here just trying to get to the end of my problem the best way i know how..if i offend anyone here its purely by accident and no offense was intended..
With SURVEY GRADE gps equipment, the knowledge of knowing what calculation are being done inside the "black box", how they are affected by local site conditions, and current precise satellite orbits, one can easily mark your locations repeatable to within the manufacturer's specifications of a few centimeters.
If your coordinates to be staked, are not that accurate to the intended position, (IE, sounds like an excavation site), then your coordinates on the ground will reflect that lack of accuracy but can still be precisely located and staked.
How accurate does your on the ground excavation site need to be? Contained within 1 meter, 10 meters?
Do yourself a favor and write a contract for surveying services. Sounds like lack of contracts and or lack of the understanding of what the results will be have burned you in the past with the Geotech company.
