I expect the subject to get more discussion after everyone returns from the weekend. I’ve tried to summarize [msg=277198]one of the longest[/msg] threads we’ve had in months. If one were to print it out as it appears, it would run to near 50 pages.
If anyone, especially the original poster, can add hard facts to, or correct this summary, please do, but let’s not repeat things that have been repeated many times.
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Mr. looking4aspot, who has no surveying background, is trying to find something of significant historical and possibly monetary value buried in the ground within 25 acres in North Carolina owned by his family.
He is cautious about sharing information, but once he understands what a professional surveyor can and can’t do for him, may hire one and share all the information with that person. The surveyor needs to be willing to digest all the background information and not merely stake out some numbers on the ground.
Some have suspected his post to be a troll, but others are convinced he believes what he has posted.
He believes the buried item was intended to be located from the “copious amounts of info” he has, that was prepared by “engineers, military and naval, surveyors, mathematicians, mining engineers, genious, all wrapped into a few people” around 140 years ago."
He derives from that documentation what appears to be latitude and longitude for 9 points in an uncommon format of DD.MM.mmm North and West, that could be someone’s personal shorthand.
He appears to have no detail about how the numbers were determined 140 years ago. If his latitude and longitude numbers involved any calculation on his part, such as using bearings and distances, then he needs to tell the experts the ORIGINAL data, not something he derived from it.
He has used a consumer grade GPS (with a repeatability of perhaps 10 feet under the best conditions and often worse), aerial pictures (Google Earth?), etc, to guide the digging of large holes, and found what he thinks he was supposed to find in the holes at 8 of those points.
“The coordinates were supplied in an order...we excavated each and at each learned from our excavation where in the documents to locate the next set of coordinates, and so on.”
Some of those holes appeared to be booby-trapped just outside the target location.
He believes that digging near the 9th point without hitting the “exact” spot could destroy what he is seeking, and therefore needs the best possible estimate of that position on the ground. He mentioned geophysical measurements that turned out to not be helpful.
I’m a little puzzled by the statement that the final location is “between the crossing of the north/south and east/west lines of an exact set of coordinates”. If you are just drawing lines between pairs of the 8 found monuments, then you don’t need any fancy measurements. Just go out and sight between points. If it isn’t lines between pairs of points, then what do crossings have to do with it?
He expressed the required accuracy as having the correct least significant digit in the consumer GPS display, which is 0.001 minute and corresponds to a range of about 6 feet north-south and 5 feet east-west. Undoubtedly, he would like better if possible.
It has been pointed out that 140 year old latitude and longitude would not reliably translate to any modern measurement within a hundred feet at best and probably much worse. They cannot be expected to be accurate if plugged directly into GPS, and it is astonishing if he has found 8 correct points within practical-size holes located by old latitude and longitude.
There are two principal reasons old lat-lon values won't work: The main reason is that any measurement is relative to some framework (datum) and it may not be possible to accurately translate from one framework to another. GPS measures with respect to a global framework that has been fitted to modern studies of the earth. Old astronomical latitude and longitude measured with respect to the apparent positions of stars and/or the sun with respect to the local vertical.
The gravity vertical in various locations is inconsistent enough to affect astronomical latitude and longitude by hundreds of feet. The early government Coast Survey had its own framework (datum) that tried to account for those effects but was still many feet from today’s datum values.
Land surveys usually are with respect to local monuments on and near the subject property. Construction surveys are with respect to fixed control points on that site.
It is possible to measure extremely accurately within one framework, but translating between frameworks is difficult and rarely possible at the accuracy that can be obtained within a framework.
The second reason is that the absolute accuracy obtainable in a latitude/longitude framework 140 years ago simply was not close to modern capabilities. State boundaries marked by experts according to latitude were often found later to be 10’s to 100’s of feet from the astronomical latitude they were intended to follow, and many 100’s of feet from where a GPS latitude would fall. Astronomical longitude was even more difficult due to the need to know time very accurately.
However, the old values may accurately indicate the relation of points to each other, depending on how they were obtained. If one point and a bearing were measured astronomically, and careful angle and distance measurements on the ground of the other points were converted to calculated latitudes and longitudes, the relationships to each other could be accurate to the precision expressed, even though the location in the world was off hundreds of feet from a modern measurement.
Therefore the problem at hand is not one of measurement accuracy, but rather defining the framework within which to measure.
The best method to attempt locating his 9th point has been described by various posters in language that may not have been clear to him, and this is what he desperately needs to understand.
An expert using either professional-grade GPS gear or conventional optical instruments should measure his 8 “known” points to fraction-inch accuracy in some convenient modern framework system. A nearby 40-acre survey by the same 140-year-ago surveyors should be included if there is any data to tie it to the mystery locations.
Mathematically comparing those measurements to the old coordinates given for the found points will allow an estimate to be made of:
1) how to best translate the old framework to the modern one and therefore the best estimate of the location of the 9th point in the modern framework,
and 2) how well the old coordinates after best-fit translation agree with the modern found locations as an indication of the likely accuracy of the translated 9th point.
Put me in the "He is pulling our chain" category. Unless his last name is Gates. Then I believe every word.
Not knowing about what departments handle survey information in the USA this suggestion may not be viable, but has looking4aspot considered inquiring with a lands title office of some sort, or even the navy considering it was involved? They may both have more documentation available to ascertain a more accurate and up to date location.
If this isn't possible I would be treating the dig as if I was working around a large diameter high pressure gas main. engage a registered surveyor to mark the site as close as possible, and investigate with a ground penetrating radar. Any confirmation of findings will be carried out by exposing with a sucker truck, although depending on what it is looking4aspot is looking for this may still be too aggressive a method.
The whole project sounds like it a bit more complicated than just punching a few marks into the ground, and if the finding will be as valuable as stated then it would be worth pursuing this thoroughly.
He must be having a wonderful time annoying a group of people who routinely focus on having every scrap of evidence possible before moving forward.
It would seem reasonable that the first eight locations having already been found should make finding the ninth one a much simpler chore. That's assuming the same coordinate system was applied to all.
My guess of the find being Jimmy Hoffa's body is out based on the 140 year ago time frame.
> My guess of the find being Jimmy Hoffa's body is out based on the 140 year ago time frame.
I heard from a very reliable source that Jimmy Hoffa was ground up into hamburger meat.
James
He derives from that documentation what appears to be latitude and longitude for 9 points in an uncommon format of DD.MM.mmm North and West, that could be someone’s personal shorthand.
I am still of the opinion that Mr. Spot's coordinates are a grid coordinates that originated from someone accustom to plotting firing solutions (pirates, militia). The question in my mind is what part of the world did the map's author come from? The answer to this question would narrow down the unit of measure (rod, vara, chain, English foot, French foot, etc...). It would also give us a better understanding of which standard to attempt to adhere to, for example, if using the vara, do I use 32.91 inches per vara (Spain), 34.1 inches per vara (Argentina), or 33 inches per vara (Texas)? Additionally, his simple grid has to have a 0,0 point of beginning, which he is closely guarding.
My advice is seeking the assistance of the Surveying Historical Society and/or a military historian.
My $0.04. I hope it helps!
:good:
Good post. It seems like a good surveyor could just go to him and say that they have the ability to locate a lat. and long. to a high order of precision which is what he wants, and locate it using OPUS, and talk to him in big words and assure his accuracy to a certain precision (along with all of the pertinent metadata), and the guy would walk away thinking he has the "exact" points he asked for. The surveyor could charge $1,000 and walk away and everyone would be happy.
Instead we give him realistic information for free...and he probably thinks we're all nuts. Isn't that like a surveyor...giving all kinds of real and good help, and not charging a dime, when they could be cleaning up.
Great summary, thanks for the effort
if the timeline is about 140 years - that's too new for anything with the Lost Colony of Manteo. North Carolina - maybe the Wright Brothers family? they were both born 1867 -1871 or so. Still so vague.
thanks for the link and compilation. Fun Posts! I don't see anyone mention doing a calibration with RTK, specifically. maybe I missed it. If he has 8 found points and the missing one is relative to those 8, I would locate them all with RTK and tweak a calibration to get minimal residuals and stake that last point.
It might not get him exactly where he wants to put a shovel in the ground, but it could minimize his search area considerably.
AJ
I'm thinking it may be an 1870's survey of something much older.
James
personally, I'd rather go look for the Egyptians in the Grand Canyon..
regarding this bill, I’m a little puzzled by the statement that the final location is “between the crossing of the north/south and east/west lines of an exact set of coordinates”. If you are just drawing lines between pairs of the 8 found monuments, then you don’t need any fancy measurements. Just go out and sight between points. If it isn’t lines between pairs of points, then what do crossings have to do with it?
a lattitude line and a longitude line cross..at this crossing point there is a measureable amount of property at that crossing point....it is only the property within the confines of an exact coordinate point i am interested....not drawing lines off of other locations but thats a thought..
Degrees of latitude and longitude can be further subdivided into minutes and seconds: there are 60 minutes (') per degree, and 60 seconds (") per minute. For example, a coordinate might be written 65° 32' 15". Degrees can also be expressed as decimals: 65.5375, degrees and decimal minutes: 65° 32.25', or even degrees, minutes, and decimal seconds: 65° 32' 15.275". All these notations allow us to locate places on the Earth quite precisely – to within inches.
A degree of latitude is approximately 69 miles, and a minute of latitude is approximately 1.15 miles. A second of latitude is approximately 0.02 miles, or just over 100 feet.
A degree of longitude varies in size. At the equator, it is approximately 69 miles, the same size as a degree of latitude. The size gradually decreases to zero as the meridians converge at the poles. At a latitude of 45 degrees, a degree of longitude is approximately 49 miles. Because a degree of longitude varies in size, minutes and seconds of longitude also vary, decreasing in size towards the poles.
rods and chains....i merely said there was naval experience, not that any navy had participated..and first recorded survey of property at all s from 1960s
that would be okay...i'd probably go right along with it..the dig would prove easily right or wrong..
haha nowhere near all the crater holes around bedford read a little about that...they say even mel fisher dug him a hole there..
nothing at all about rights..merely uncontrollable circumstances should i be off too far...i also noted on bills rework of the thread {which is great bill thanks alot} he said something like reasonable holes dug to locate other locations ...well on most...one was about 100 ft across, another nearer 300 ft across, before we located bullseye...
> a lattitude line and a longitude line cross..at this crossing point there is a measureable amount of property at that crossing point....it is only the property within the confines of an exact coordinate point i am interested....not drawing lines off of other locations but thats a thought..
>
There is no measurable amount of property at the intersection of Latitude and Longitude. That is a precise point. The location of the point will fall within error ellipses depending on the accuracy of the measurements.
nah gschrock you are getting off base a bit....jaro has the right mindset it seems..not after nick cages treasure, nor any miners, wild west cowboys, pirates, bankers or long gone government officials...not even hoffa hes buried at a football field....just looking 4 a spot.
By your own definitions, seconds of latitude to three decimal places only get you to about 28 feet precision. Perhaps less precise than you have imagined. Maybe close enough still for your purposes.
Circumference of the earth at the equator = 24,900 miles.
24,900/360 = 69.16667 miles per degree
69.16667/60 = 1.15278 miles per minute
1.1527 x 5,280 = 6086.667 feet per minute
6086.667/60 = 101.444 feet per arc second
To use your example, that shows the latitude to xx.275 seconds
101.444 x 0.275 = 27.897 feet.
Needs to be expressed to five decimal places to be pinpoint.
Still, 27 feet puts you in a fairly confined neighborhood.
if not mistaken, minutes and seconds, in relation to coordinates, are a measurement of distance not of time..