Ngs - 2 Or 3 Levels Of Destroyed ?

[+Black Dog Trackers]

How often has it happened, when looking through a list of PIDs, you figure this one is worth looking for, and then the last sentence of the description says: "the mark is destroyed". These things are like weeds!

 

Here are 3 examples: hv4301 hv4326 hv4355. (For comparison, hv1919 is actually coded "Destroyed".)

 

In the first example, the CGS made the report, coded the PID's condition as GOOD and in the description said it was Destroyed. In the second example, the NGS coded the mark as Not Found and then said it was Destroyed. In the third example, the CGS coded the mark as Not Found and then said it was Destroyed.

 

The easiest thing is of course to ignore these PIDs. However, I was wondering if the NGS would prefer that all these get coded as Destroyed. Perhaps over the years coding rules have changed. At this point, unless someone at NGS develops some 'fuzzy-logic' program to read the descriptions for evidence of "Destroyed" and to figure out the context, there is no real way to fix this.

 

Unless we can help. It would't be difficult to make some kind of note to the NGS (maybe a PID list now and then) indicating that a PID's description says the PID is destroyed. I'm not talking about us claiming or determining that the PID is destroyed, merely that the description itself says that it is destroyed. Maybe the NGS would rather just leave these coded as Not Found and Good, I don't know. On the other hand, if we could help somehow with a big data cleanup........

 

Any comments?

NGS?

[+Zhanna]

I've come across a few of these and have submitted them to Deb. As long as the text stated clearly and without a doubt that the mark was destroyed, she marked them as such in the database.

 

One or two datasheets said something like "it is assumed [for whatever reason] that all of the marks were destroyed." There was no mention of the structure the mark was on having been torn down, or of the surveying party intentionally destroying the marks when setting new ones. In those cases, Deb left the datasheets as-is.

 

I agree: if there's no doubt, why not clean up the database, and keep everything consistent?

 

~Zhanna

 

http://surveymarks.planetzhanna.com/

[ArtMan]

I've adopted a term that I've seen in quite a few NGS recovery notes -- the station is presumed "lost."

 

It doesn't have the finality of "destroyed," but it does suggest that after careful consideration of all the evidence, it is most likely that the station is destroyed, but that there is insufficient evidence for a report of "destroyed" to the NGS.

 

-ArtMan-

[Gnikhog]

I'm not sure what value a list of PIDs that 'might' be destroyed based on the datasheet text provides to NGS. Unless there is evidence collected and presented to make the 'destroyed' determination, I think the PID should remain active in the database. I'm sure a professional needing a nearby mark will simply choose another, not wanting to waste time looking for something that may no longer exist. On the other hand, perhaps this is where we can add some value by either recovering the mark or confirming, documenting, and reporting its destroyed status.

[+Black Dog Trackers]

Gnikhog -

 

If you check the examples I gave, you'll see that it was the NGS and its predecessor, the CGS, that declared the PIDs destroyed in the text. These examples aren't 'might be' or 'presumed lost' situations. I suspect instead a difference between then and now on coding, but I started this topic to hear primarily from the NGS about these and how they came to be stated as such in the database without matching coding.

 

================

 

Zhanna -

 

Interesting.

I think I should try sending to Deb the unequivocal ones as you did!

Edited May 3, 2005 by Black Dog Trackers

[Z15]

Like this?

 

RL1538'DESCRIBED BY US LAKE SURVEY 1871

RL1538'ABOUT 1/2 MILE NORTHEAST OF PORTAGE ENTRY LIGHTHOUSE, ON

RL1538'EAST SIDE OF KEWEENAW POINT, AND IN 1871 NOT MORE THAN 10 FEET

RL1538'BACK FROM EDGE OF BLUFF RISING NEARLY VERTICALLY 44 FEET

RL1538'ABOVE WATER. MARKED BY STONE POST. WITNESS MARK, HEAD OF NAIL

RL1538'DRIVEN INTO BLAZED HEMLOCK TREE, BEARS N. 43 DEG 53 MIN W.

RL1538'FROM STATION AND IS DISTANT 59.75 FEET. IN 1929 IT WAS REPORTED

RL1538'THAT BLUFF WAS SOFT, AND ERODING, AND THAT STATION MARK

RL1538'HAD PROBABLY CAVED INTO LAKE. IN 1934 STATION WAS REPORTED

RL1538'DESTROYED BY EROSION OF BANK.

Edited May 3, 2005 by Z15

[caseyb]

I would suggest that you send them to Deb.

 

-Casey-

[Z15]

I sent the one I posted to Cherly a while ago..

[joegeodesist]

We should expect that recreational reconners usually have less patience than trained professionals who really want that specific mark to solve a legal or engineering problem. We should accurately record a reconn person's impression of the probability of a mark's existence but avoid painting all with one broad brush.

 

DESTROYED has always meant we saw it destroyed and nothing else; NOT FOUND is like being listed as a POW; we will always keep hope alive.

 

For marks which are really impossible to recover, traditionally we make some notation in the recovery text like station not found, area now permanently flooded. I agree it would be nice to have a database code which keeps folks from wasting time on repeated searches.

 

I'd prefer a modifier for NOT FOUND: either a probability factor or time spent on search.

[Z15]

I like this one

 

RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1996 (GAS)

THE BUILDING HAS BEEN RAZED. ASSUMED DESTROYED.

 

 

I was scanning for a mark on my laptop db and came across one that said.

 

RECOVERED IN GOOD CONDITION, THIS MARK HAD PREVIOUSLY BEEN REPORTED AS DESTROYED.

Edited May 5, 2005 by Z15

[kc2ixe]

We should expect that recreational reconners usually have less patience than trained professionals who really want that specific mark to solve a legal or engineering problem. We should accurately record a reconn person's impression of the probability of a mark's existence but avoid painting all with one broad brush.

 

DESTROYED has always meant we saw it destroyed and nothing else; NOT FOUND is like being listed as a POW; we will always keep hope alive.

 

For marks which are really impossible to recover, traditionally we make some notation in the recovery text like station not found, area now permanently flooded. I agree it would be nice to have a database code which keeps folks from wasting time on repeated searches.

 

I'd prefer a modifier for NOT FOUND: either a probability factor or time spent on search.

Heh,

Deb just recently listed a benchmark destroyed that I submitted, and 1)I didn't SEE it destroyed, and 2)it wasn't an intersection station!!

 

Whant the story Look at KU3824 The mark WAS on the roof of the building - the building is GONE (torn down 1941) and the area is now a park. Sent Deb pictures of the park, plus pointed out that the 1941 note said it was about to be destroyed, and it's place was taken by KU3822

 

Good enough I guess

[joegeodesist]

okay, I'll admit a building is a bit harder to misplace than a buried lump of concrete.

 

I'll stick by my P.O.W. analogy and hope for a qualifier to the NOT FOUND category.

[+bicknell]

I understand the NGS's problem, and reluctance to accept a destroyed without proof, however there are also some clear cut cases around here that I think should be destroyed.

 

I found one locally where it was a disk in a bridge wingwall set in 1942. The bridge was replaced in 1962 (per vdot), and in 1996 (the bridge I found with a plaque). Neither time was a disk reset. The description matches, there's no other roads crossing a stream in a 2+ mile radius, scaled coordinates are right on, it's on a line of benchmarks and is the only one missing along there. Visting the site it's clear the road could not move much to either side (it's a narrow valley), and there's no sign of any old bridge parts on either side of the new bridge.

 

I am 100% totally sure this benchmark is gone. I think anyone who visted the site would come to the same conclusion. However, it was a disc, and I can't produce it to show that it's mounting was destroyed.

 

While this bothered me when I first started, I've gotten over that so I don't care too much anymore. At the same time, this is going to continue to waste peoples time, if only geocachers you want to see if they can find a "not found" mark by going back there.

 

Another case that seemed a bit odd to me, I found a triangulation station where my GPS put me in the middle of a mall parking lot. Several people pointed out the benchmark could be under the pavement and still there. Well, that's all well and good, but considering the likelyhood that it wasn't damanged / moved when the lot was paved, or that if you were to be able to dig up the lot to find it you wouldn't damage and/or move it in that case, and that you can't survey it if it is under pavement I really wonder about the wisdom of keeping the entry in the database.

 

Obviously there are many more marks that simply have bad descriptions, or are buried which might turn up later, and the POW treatment is absolutely correct for them.

 

Ah well, of minor concern to me.

[caseyb]

I am 100% totally sure this benchmark is gone. I think anyone who visted the site would come to the same conclusion. However, it was a disc, and I can't produce it to show that it's mounting was destroyed.

 

i would suspect that you could send this story to Deb, along with a photo of the new bridge and any other "documentation" you can think of, and she will list it as destroyed.

 

-Casey-

[ArtMan]

At the same time, this is going to continue to waste peoples time, if only geocachers you want to see if they can find a "not found" mark by going back there.

Well, that may be the case if you simply report it as "not found" and leave it at that.

 

However, if you provide a full explanation in your NGS report as you did here, I don't believe anyone is likely to see if they can prove you wrong.

 

In my experience an unadorned "not found" filed by USGS or a state agency is of more probative value than one filed by an individual, and a report with an explanation such as you provided or along the lines of "two men searched diligently for 45 minutes" is of more value than a simple "not found" without any further explanation.

 

I respect the NGS for the high standards required to classify a mark as destroyed. And after all, it's their database. In the real world there are shades of gray, and in the NGS database there are shades of "not found." I can live with that and provide as much information as I possibly can to aid those who come after us to assess the value of my report.

 

-ArtMan-

[Bill93]

Maybe the case for your bridge is a little better than the one I had, but this one taught me caution: NJ0584. And this one is another example where I was lucky to not get fooled: LE0221.

[+Black Dog Trackers]

bicknell -

 

I think ArtMan makes excellent points. I will add that there is a tradeoff in 'wasting time'. There is an amount of wasted time, X, in looking for a mark and determining, as you did, that it isn't there. There is another amount of wasted time, 200X, in establishing a new mark when a local mark that actually still exists and is findable with effort but unfortunately is rendered invisible in ordinary listings due to a 'destroyed' report on it.

 

Another factor thingie is that if you find a mark, they put your initials in the database, whereas if the NGS agrees with you on your evidence that a PID is destroyed, your full name gets in the database, so everyone knows who gave the NGS strong evidence that the mark was destroyed.

 

As for the 'under the asphalt' situation, check this out! This mark seems to have been exposed by removing the overlying asphalt.

[+bicknell]

I may try and get my bridge destroyed. If I do, I need to go back and take more pictures. I finally dug up the PID, and I don't have enough pictures showing the area around the bridge.

 

Anyway, here's my bridge mark: JV3108

[holograph]

Bicknell,

 

I've come across a couple of bridges that I've reported NOT FOUND with comments like the following: "The bridge currently at the location bears the date 1979. The abutments were examined from the deck of the bridge and no mark was found." I figure that's enough to let anyone following in my footsteps to judge whether it's worth their while to search again.