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New To Benchmark Hunting


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Mrs. CC and I have recently discovered the joy of benchmarking. We found one by complete accident a few days ago, and tonight found another. In the first case, there were no distinguishing marks on the disk, except a year. In the second case, there was a designation number but no PID.


In the first case, it was right next to a cache, so we were able to find it here by the "find nearest benchmark" feature. The second one however posed a bit of a problem. There doesn't seem to be a way to search for a benchmark via designation. We pretty much had to use an areal map figure out its location, (doing to lat/long calculations) to log it.


So my questions are this: what is the association between PID and Designation? If you find a benchmark and don't have the coordinates (say by accident and you don't have your GPSr), how do you log the find here?


Thanks !

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You can search by "Station Name" also called "Control Point Name" also called "designation" (by Geocahing.com) at the National Geodetic Survey (NGS) NGS Datasheet Page. Click on "Datasheets" and then "Station Name". Works OK. One problem is that even in one state, the "Station Name" may not be unigue. You may have to do a little detective work by Lat/ Long. Good luck! Don't forget, if it is "scaled", it's location can be "off" by 600 feet + your GPS error (maybe 25 ft).

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So my questions are this: what is the association between PID and Designation? If you find a benchmark and don't have the coordinates (say by accident and you don't have your GPSr), how do you log the find here?

Just to clarify, the PID (Permanent Identifier or Identification) is a combination of letters and numbers in the form LLNNNN used to keep track of benchmarks in the National Geodetic Survey database (from which the information on geocaching.com is derived).


The Designation is the "name" of the benchmark and often corresponds to the stamping on the benchmark disk (if there is one). Sometimes, these names can be quite colorful and have a bit of history behind them. You might find one at a mental hospital called INSANE (from when the institution was formally known as the County Hospital for the Insane), or one called JONES for the name of a nearby street or BARKLEY for the name of the surveyor who set the point. Along a given road you might find, at regular intervals, a series of marks such as F89, G89, H89, etc., which would represent a series of true bench marks (set for elevation, not latitude and longitude), with the height of each one determined from the previous one.


Many benchmarks have Azimuth Marks and Reference Marks associated with them, and sometimes these marks are independently assigned PIDs of their own: you might find triangulation mark SAUL not far from SAUL RM2 and SAUL RM3 and, perhaps a half-mile away, SAUL AZ MK. (But more commonly, these ancillary marks do not have their own PIDs.)


Hope this helps some.



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CC -


To expand a bit on Artman's reply, the PID is controlled by NGS and is unique. There is one and only one HU1800, for example. Station names or designations(usually, that which is stamped on the disk, but not always) are not unique. There may be many marks designated SMITH in the database. Heck, there may be several SMITH 1962 for that matter. To the best of my knowledge, a disk's PID is never stamped on the disk. That is, the PID and the designation are never the same six characters.


(Now that I've made this assertion, someone will find that one station out of 733,000 where the PID and the designation are the same.) DaveD probably knows it off the top of his head.


Were I to find a mark while out and about doing something else, here's what I would do: First, I would note the info on the mark itself - the agency and designation, etc. For example, I might note that this disk was a C&GS disk stamped SMITH 1935. Second, I would make a good mental note of where I was; say 30 feet south of the center of Jones Road and six feet west of utility pole 99999, about one half mile south of Rte 123. Later, I would consult a toposheet and/or my MapSource software to get the approximate coords of that spot on Jones south of 123. Finally, I would run a search on those coords and check the nearest dozen or so stations to see if any conformed to the disk I found. If one did, I would log the find and include the comment that coords and photos are not included because this was an unplanned find.


Later, I would go back and confirm the coords with my handheld and take the semi-obligatory photos and add them to my post for this station.


I've gotten a couple of effortless finds this way.



Edited by seventhings
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