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ArtMan

Two stations or one?

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In Staunton, Virginia, we have a mystery.

 

There are two marks called STAUNTON. One is HW3497, and the other is HW3235. They appear to describe the same object, a traiangulation station disk set in the lawn at the highest point on the campus of Mary Baldwin college, near a flagpole and artillery piece.

 

The horizontal coordinates are the same, given that HW3497 is third order horizontal control, and HW3235 is scaled.

 

HW3235 is a first class vertical control station, with elevation of 1568.19 feet (adjusted).

HW3497 is a "third ?" class vertical control station, with elevation of 1383.9 feet (vertcon).

That's a 115 foot disparity!

 

There is some language, which frankly I do not understand completely, on the HW3497 datasheet regarding the computation of the elevation, but which wouldn't seem (to me) to explain this big difference.

 

The NAVD 88 height was computed by applying the VERTCON shift value to

the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.)

The vertical order pertains to the NGVD 29 superseded value.

As I read the USGS topo map, the correct elevation should be approximately the 1568' given on HW3235. And HW3235 appears to be a more modern measurement, but surely even in the 1930s, when the disk was monumented, leveling was reasonably accurate ... certainly to within 100 feet!

 

So my questions are: Why is the same object assigned two different PIDs? How common is that? (I don't believe I've ever run across it before.) And what accounts for the disparity in elevation for the two stations STAUNTON?

 

-ArtMan-

Edited by ArtMan

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Good job Atman. HW3497 and HW3235 are the same station. The current elevation for HW3235 was erroneously copied from HW1575 (STAUNTON BM). This type of error goes back to the days in the late 70s when NGS was transferring all the paper copy horizontal and vertical data to a digital database. There are numerous examples of stations that are separate horizontal (triangulation) and vertical (bench marks) that have the same name (or very close) and are in the same area. Unfortunately the team of cartographers assigned to this task were not trained surveyors and errors like this pop up from time-to-time. Thank you for bringing this to our attention. I have sent a note to the NGS data base team to make the appropriate corrections. This type of data checking provides NGS with a valuable resource to help us strive to make the data in the National Spatial Reference System as perfect as humanly possible. This is another example of the very positive impact the geocaching community is having on this important part of our national infrastructure.

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Thanks for your posting about DU1323 and DU1930. I just had an e-mail from our Arizona state geodetic advisor who visited the site yesterday and confirmed that there's only one mark there. The problem on our end is to figure out which height is correct. Once we've reviewed the data and can make a determination we'll make the necessary changes.

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Congratulations, Art Man!

 

I'm thinking that we should form an exclusive club for benchmark hunters who get a "two-fer." :( My application is in Morro Bay Mysteries Thread

 

Or perhaps a new contest ........ :P

 

cjf

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If you have some time, you can do what I've started on the NM data. This is the tedious way, for folks with no programming skills.

 

1) Go to my webpage with the state by state spreadsheets.

 

2) Download a state, unzip, open up the spreadsheet and sort by Designation, then County, and then PID. Be sure to maximize each column, so the full names are displayed.

 

3) Open up a browser with two Geocaching.com/mark pages.

 

3) Look for two stations in the same county with the same name. Enter the PIDs into the two browser pages, and compare the coordinates/maps. The maps will be easier to spot check.

 

I've gone through about 1/3 of NM and found AF9513 and AA9188, which I had known about before (and I think I emailed Deb; they're oddly listed in the real NGS database when I checked today)...I'll finish NM soon.

 

For folks that can program, you can download all of the counties for a state, run them through the program that pulls the data from the datasheets into a | separated form, using the PID, DESIGNATION, coordinates, and benchmark category. Then you can program a search/print that will compare names (try just for duplicate names, and expand to more sophisticated name matching), compare counties, and then compare coordinates. If it's within an arcsecond or so, I'd print it out. This should give you mostly station/RM 1/RM 2/AZMK combinations, but it will have the duplicates in there as well.

 

Alternatively, focusing on the coordinates is probably a better way to go. Grab the coordinates for each station and then compute those that completely overlap, or are within 1 foot (arbitrary) of each other. This would give you a much smaller group of candidates, with the pollution being RESET stations. However, that will help a bit too. You won't get the odd situations where you have the same station w/ two PIDs, one for horizontal and one for vertical, or other oddities. However, what you get should be a lot easier to handle.

 

If you'd like a zipped form of the state by state merged datasheet files (big old text files), email me. My copies are archived as of last fall, but should be fine for this search.

 

I think I might spend an hour or two with Matlab, working on the state by state datasheet files this weekend. I'll try to create candidate lists (much smaller than the state by state ones) for folks to work through.

 

I suspect there will probably be 100-150 double stations (200-300 stations total) in the database.

 

Holograph can probably do this in 5-10 minutes, but...I'll give it a whack.

 

This is the sort of useful thing we can do for the NGS on the computer, not in the field. It won't find all of the duplicates, but will probably get over 90%.

 

As a note, has anyone noticed that the clock at the bottom of the page (Time is now: ) and the "This message edited at:" (which is 1 hour west of Pacific Daylight Savings Time) are hopelessly out of synch with real time?

Edited by BuckBrooke

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Very interesting. A quick check of Missouri shows 35 pairs of stations with the same designation in the same county and 2 sets of 3 stations with the same designation in the same county. One of the 3s is local to me although I (or anyone else on GC) has visited. A visual checks shows that JC1652, JC1653 and JC1654 appear to be different markers although trying to compare the various descriptions this late at night is difficult.

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Yes, DU1323 and DU1930 are the same disk.

 

Dave, how sure are you?

 

AZcachemeister visited the location of DU1323 as listed in the 'official description' and found this...

 

e5ff4a8b-22c2-4004-8848-261721786dce.jpg

 

He also visited the location of DU1930 as listed in the 'official description' and found this....

 

1117ef7b-3307-4001-8b13-0d04b6e3c6aa.jpg

 

If we follow the written description and find the benchmark is gone and there is a hole in the ground where it should be that would be considered 'Destroyed'.

 

We have here 2 different benchmarks (PIDs) that were monumented in different years (1970 & 1978) and adjusted vertical controls that are different from each other (1568.69 & 1567.98). Also the written description takes you to 2 different locations.

 

Dual name close together may be rare but they do happen as in FQ0607 & FQ0713 both named Grandview and less than a mile apart.

 

Without seeing the original paperwork, it sure appears to be 2 different benchmarks.

 

John

Edited by 2oldfarts (the rockhounders)

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A rather old thread, that I am surprised has not had more recent entries; but it seems to fit what I came across at Lund UT yesterday.

 

USGS 5092 UNK DATE

 

09663631-9c0d-4f0a-9204-bb838c1b7be1.jpg

 

A bit surprised that no one has even done a NOT FOUND/DESTROYED log on this one, as the only thing close to its DS L/L is

 

CHISELED SQUARE IN GRANITE POST

7c20c6dc-9a28-4b49-b522-e9ccff5dd312.jpg

 

Copy/paste of my note at LUND BM

 

'I think that this is a case of double data sheets for the same mark.

 

JO0569'DESCRIBED BY US GEOLOGICAL SURVEY 1938

JO0569'REACHED STA. LUND FROM THE DEPOT AT LUND BY GOING SSW 0.1 MILE TO THE

JO0569'GRADE CROSSING, CROSS TRACKS AND BEAR RIGHT ON THE TRACK ROAD

JO0569'TOWARDS THE LOADING PENS FOR 0.18 MILE TO STATION.

 

As I read it, the USGS found this existing mark

 

JO0306'AT LUND, IRON COUNTY, ON THE UNION PACIFIC RAILROAD, ABOUT 243 FEET

JO0306'NORTHEAST OF THE OPERATORS OFFICE IN THE STATION, ABOUT 95 FEET

JO0306'NORTHWEST OF THE CENTER LINE OF THE MAIN TRACK, IN THE SOUTHWEST ANGLE

JO0306'OF THE LARGE Y, AND ABOUT 2 FEET LOWER THAN THE TOP OF THE RAIL. A

JO0306'UNITED STATES GEOLOGICAL SURVEY STANDARD CAP, STAMPED 5081.532 R LUND

JO0306'AND RIVETED TO THE TOP OF A 3-INCH IRON PIPE.

 

and maybe even did the elevation over-stamping (there is a 5092 under the 5081.532) and encased it in concrete without documentation , but did not plant it

 

JO0569 HISTORY - 1938 MONUMENTED USGS'

 

At least these two agree on elevation:

 

JO0306* NAVD 88 - 1549.960 (meters) 5085.16 (feet) ADJUSTED

JO0569* NAVD 88 - 1549.95 (+/-2cm) 5085.1 (feet) VERTCON

 

I need to get back on the road and try to get north of SLC before the next blizzard. When I get a chance I'll dig into Special Publication #18 to see if USGS 5092 was occupied in 1908.

 

kayakbird

 

PS to TillaMurphs - snoop my recent note and back track to a recent found..

 

PS #2 Found it.

 

SP #18 P. 215 PRECISE LEVEL NET ADJUSTMENT AND STANDARD ELEVATIONS.

 

5092 R Lund.-At Lund, Iron County, Utah, 29 meters northwest of the center line of the main track of the San

Pedro, Los Angele3 & Salt Lake Railroad, 74 meters northeast of the operator’s office in the railroad station; set in the southwest angle of the large Y, 0.7 meter below the top of the rail. (Note 18.”) MEL

Edited by kayakbird

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Back home safe and sound with the leisure to finally read the DS for LUND JO0305,

which I saw, but decided that I did not have time to log. A bit more information

in its DS should help verify that LUND BM and USGS 5092 are exactly the same mark.

 

JO0570 STATION LUND BOX SCORE JO0569 LUND BM 165.127 METERS 10925

1938 STATION LUND RECOVERY ---- U.S.G.S.BM IS AN IRON PIPE WITH CAP.

 

This 1938 TO FIND for STATION LUND reads almost identical to the one for LUND BM.

 

JO0570'REACHED FROM THE DEPOT AT LUND BY GOING SSW 0.1 MILE TO THE

JO0570'GRADE CROSSING, CROSS TRACKS AND BEAR RIGHT ON THE TRACK ROAD

JO0570'TOWARDS THE LOADING PENS FOR 0.18 MILE TO STATION.

 

JO0569'DESCRIBED BY US GEOLOGICAL SURVEY 1938

JO0569'REACHED STA. LUND FROM THE DEPOT AT LUND BY GOING SSW 0.1 MILE TO THE

JO0569'GRADE CROSSING, CROSS TRACKS AND BEAR RIGHT ON THE TRACK ROAD

JO0569'TOWARDS THE LOADING PENS FOR 0.18 MILE TO STATION.

JO0569'

JO0569'U.S.G.S.BM IS AN IRON PIPE WITH CAP.

 

LUND BM just needs a bearing and distance to make it useful.

 

While doing this research I discovered that there is another double PID in the same area

 

NonPub LUND GRANITE POST

 

aa8851a9-68b7-435e-b8ac-9b9f4e3ca04d.jpg

 

>JO0571 LUND GRANITE POST 38 00 27.5/113 26 00.7 2 DD

>JO0571 LUND GRANITE POST 38 00 27.5/113 26 00.7 2 NN

 

L/L match the call '62 meters northwest of the center line of the main track'

and HH2 for 1908 PLN S 8 FOUND 29 FEB 2012 38 00 27.6/113 26 00.9

 

Maybe somebody will wander by there next month and give us a second opinion. kayakbird

 

 

Copy/paste documentation:

 

SP Pub # 18. 'DESCRIPTIONS OF PERMANENT BENCH MARKS BETWEEN LAS VEGAS, NEV., AND ZENDA, UTAH, 1908.'

Page 215 PRECISE LEVEL NET ADJUSTMENT AND STANDARD ELEVATIONS.

 

JO0305 (& NONPUB JO0571)

S 8.-At Lund, Iron County, UTAH, 62 meters northwest of the center line of the main track

of the San Pedro, Los Angeles & Salt Lake Railroad, directly opposite operator’s office in

railroad station and in line with two white posts lettered “R. R. Property,’’ 0.8 meter below

the top of the rail. (Note 11.”)

 

JO0570 BOX SCORE JO0571 LUND GRANITE POST 116.566 METERS 13620 NONPUB IN 2012

1925 DESCRIPTION LUND U.S.B.M. IS 116.575 METERS (382.46 FEET) FROM STATION LUND

1938 DESCRIPTION ---- U.S.B.M. IS A SQUARE GRANITE POST WITH A SQUARE HOLE IN TOP.--

 

GE SCALED FROM DS CALLS LAT/LONG 38 00 27.5/113 26 00.8 ELEV 5089 FT

HH2 FOR S 8 FOUND 29 FEB 2012 38 00 27.6/113 26 00.9

Edited by kayakbird

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Maybe somebody will wander by there next month and give us a second opinion. kayakbird

 

 

I will need to talk to the navigator and see if we will have the extra time to check this out. We have a second moving benchmark we want to check on. We have a 2005 county download from the NGS loaded into GSAK and it has DF3585 STAKE listed in Lincoln County, NV. It is not listed on GC.com, but when I pulled up the most recent NGS datasheet it has moved west to Mineral County. Thing is the coordinates put it in Iron County ,UT. So we need to check on Both STAKE and 108 DOR to verify where they really are.

 

You might send me an e-mail detailing what you would like us to check on these marks. (Old age and all we might forget between now and then and having it in black and white will help us keep it straight.;) )

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2OF's,

 

I think that you will find your STAKE at the L/L in Iron Co Utah. DSWORLD pegs it on GE 1.3 miles east of the state line. I do think that the part of the TO FIND is in error and needs to be deleted.

'TURN RIGHT ON DIM RD 'TURN RIGHT ON DIM RD FOR 7.05 MI, TURN LEFT ON DIM TRACK RD, FOLLOW DIM TRACK RD TO TOP OF LOW HILL AND STATION.,'

 

Mostly kidding on needing more info from Lund - do wish that I had taken track to mark measurements (too windy the day I was there) but I am finding that GE to a FOUND HH2 works quite well.

 

You might take a quick look for B 8 about 900 ft northeast of the DS L/L. That location fits the SP PUB #18 better, but I am afraid that the construction of the barrow ditch took it. C 8 was lucky to have survived.

 

'B 8.-At Tomas, Iron County, Utah, 38 meters southeast of the center line

of the main track of the San Pedro, LOS Angeles & Salt Lake Railroad, 23 meters

southeast of signboard “Tomas, ”(measured along the track); set at foot of

low rocky ridge, 1.2 meters below the top of the rail. (Note 2.*) '

 

Happy Hunting, MEL

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