NGS Database error or???

[kayakingphotos]

I've been thinking about getting back into looking for benchmarks, and I noticed some "unusual" data on a number of datasheets. 

 

Quite a few sheets that I've looked at have "HD_HELD1" horizontal position for previously "SCALED" marks. No recovery updates indicate that they were actually found. Has somebody been inventing their location or is something funky going on with the NGS database?

 

Here are some examples: PH0214, PH0216, PH0217, PH0218.   PH0214 was last listed as "Not found" in 1970.... The others have a recovery on an "UNK" date

 

Patrick

[Z15]

I noticed this before and I think I recall that someone mentioned (years ago) that they were mining geocach recovery notes for that data. Someone derived a script to collect that data, if I recall correctly.

Edited March 20, 2022 by Z15

[DaveD]

These are not in error.  All of those are USC&GS bench marks that have relatively accurate horizontal positions that were determined in 1942 by the U.S. Geological Survey.  Their values are published on the North American Datum of 1927 (NAD 27).  I harvested them and simply transformed the coordinates to NAD 83.  They more than satisfy the requirement to be labeled as HD_HELD1.  I have performed similar transformations for several thousand scaled marks that had been set by USC&GS and later positioned by USGS.  Regrettably the vast majority of horizontal control established by USGS was never formatted and provided to the National Geodetic Survey for inclusion in the National Spatial Reference System.  

[kayakingphotos]

Thanks for the info. I guess I'll have to hunt down some of them and see if they are still around. Having relatively accurate coordinates might help quite a bit. I doubt I'll ever make it to the ones I listed though since the property there is POSTED and PATROLLED.....

 

DaveD, are you also pulling photos from the Geocaching website to include in the datasheets? PG0958 for example.

 

Patrick

[DaveD]

I don't specifically remember PG0958, but in general yes that's probably me.  In general, I review posts each day to see if someone has posted good quality pictures and/or hand-held values for scaled bench marks.  I never post a recovery for a mark found by a geocacher since I did not recover the mark myself.  I validate all hand-held positions to ensure that the match the station description.  Assuming all of decent quality I can then upload them to the NGS Integrated Database.  Having spent years on the NGS datasheet committee I still feel a commitment to do what I can to improve the quality of the reference frames.

[+Michaelcycle]

Thanks for your efforts Dave, that's great! My benchmarking has slowed down some lately but I always try to include a detail, an eye level and a westward looking setting photo for each benchmark I find. I will try to include handheld coordinates for any scaled marks I find from now on (and maybe go back and get them for some local marks.)

[DaveD]

Excellent Michaelcycle.  I must admit to a certain level of frustration when I see a note posted by a geocacher that they found a bench mark with a scaled position and it was "way off" but then they don't provide the value they got.

[kayakingphotos]

Dave, maybe 10 years ago I hiked to a triangulation station disk that hadn't been logged since 1983. I didn't report it since its on private property and I was never able to get good contact info for the property owner (I have access via a relative's hunting lease)

 

If I make it back to it this year and find it, do you want it logged even if I can't get property owner info?

[DaveD]

It's always best if you owner contact info, but if that's not available for whatever reason than yes submit reports detailing mark conditions.  Having an updated recovery does not in any way indicate general right of access on private lands.

[Bill93]

Noting that it is on private land is important. Owners change, so names may become out of date.

[kayakingphotos]

I'll see what I can do about landowner info. Its not exactly a station where somebody will stumble across it and trespass accidentally..... It's about a 10 mile drive off of the public road.

 

PH1673