Apparent Discrepancy In Datasheet

[ArtMan]

Station PIMMIT RESET (HV9372) is a Third Order vertical station with scaled horizontal coordinates. Yet the station is marked by a horizontal control disk:

 

HV9372_MARKER: DH = HORIZONTAL CONTROL DISK

 

This station is not in the Geocaching.com database.

 

Is the MARKER designation likely to be a mistake? Is it possible that the wrong disk was inadvertently used? That they ran out bench mark disks?

 

Unfortunately, I was unable to find the disk, so I have only the datasheet to go by. Any ideas?

 

-ArtMan-

[Z15]

It appears someone reset the mark and it was downgraded to vertical only. Since the mark was a horizontal mark to begin with, that was what they used to reset that mark but for some reason NGS would not puiblish the horizontal position. Many times these reset marks are done locally using sub-standard equipment and procedures that iits intergrity is now questionable. I know its indicates NGS but it may not have been NGS that did the work, it may have been done locally and sent to NGS. Any mark that is not tied to other marks will always be of questionable position because it cannot be verified.

 

 

The NGS Data Sheet

See file dsdata.txt for more information about the datasheet.

 

DATABASE = Sybase ,PROGRAM = datasheet, VERSION = 7.16

 

*** NOTE - The station below is destroyed.

 

1 National Geodetic Survey, Retrieval Date = APRIL 10, 2005

HV2273 ***********************************************************************

HV2273 DESIGNATION - PIMMIT

HV2273 PID - HV2273

HV2273 STATE/COUNTY- VA/FAIRFAX

HV2273 USGS QUAD - FALLS CHURCH (1994)

HV2273

HV2273 *CURRENT SURVEY CONTROL

HV2273 ___________________________________________________________________

HV2273* NAD 83(1993)- 38 54 31.97825(N) 077 12 47.31193(W) ADJUSTED

HV2273* NAVD 88 - 150.569 (meters) 493.99 (feet) ADJUSTED

HV2273 ___________________________________________________________________

HV2273 LAPLACE CORR- -1.87 (seconds) DEFLEC99

HV2273 GEOID HEIGHT- -31.77 (meters) GEOID03

HV2273 DYNAMIC HT - 150.486 (meters) 493.72 (feet) COMP

HV2273 MODELED GRAV- 980,074.3 (mgal) NAVD 88

HV2273

HV2273 HORZ ORDER - SECOND

HV2273 VERT ORDER - SECOND CLASS 0

HV2273

HV2273.The horizontal coordinates were established by classical geodetic methods

HV2273.and adjusted by the National Geodetic Survey in November 1994.

HV2273

HV2273.The orthometric height was determined by differential leveling

HV2273.and adjusted by the National Geodetic Survey in June 1991.

HV2273

HV2273.The Laplace correction was computed from DEFLEC99 derived deflections.

HV2273

HV2273.The geoid height was determined by GEOID03.

HV2273

HV2273.The dynamic height is computed by dividing the NAVD 88

HV2273.geopotential number by the normal gravity value computed on the

HV2273.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45

HV2273.degrees latitude (g = 980.6199 gals.).

HV2273

HV2273.The modeled gravity was interpolated from observed gravity values.

HV2273

HV2273; North East Units Scale Factor Converg.

HV2273;SPC VA N - 2,138,668.507 3,611,610.721 MT 0.99996128 +0 48 11.3

HV2273;UTM 18 - 4,308,993.704 308,104.409 MT 1.00005346 -1 23 25.7

HV2273

HV2273! - Elev Factor x Scale Factor = Combined Factor

HV2273!SPC VA N - 0.99998136 x 0.99996128 = 0.99994264

HV2273!UTM 18 - 0.99998136 x 1.00005346 = 1.00003482

HV2273

HV2273: Primary Azimuth Mark Grid Az

HV2273:SPC VA N - POPLAR 153 11 56.4

HV2273:UTM 18 - POPLAR 155 23 33.4

HV2273

HV2273|---------------------------------------------------------------------|

HV2273| PID Reference Object Distance Geod. Az |

HV2273| dddmmss.s |

HV2273| DC7041 PIMMIT RM 1 39.944 METERS 02219 |

HV2273| HV4807 ARLINGTON RAD STA WAVA MAST APPROX. 7.0 KM 1015747.1 |

HV2273| HV4805 ARLINGTON ATT MICROWAVE APPROX. 6.9 KM 1020453.5 |

HV2273| HV4808 ARLINGTON TV WTTG TOWER APPROX. 7.3 KM 1050453.1 |

HV2273| HV2269 POPLAR APPROX. 2.6 KM 1540007.7 |

HV2273| HV4814 FALLS CH RAD STA WOL TOWER APPROX. 2.7 KM 1553751.0 |

HV2273| HV2272 PIMMIT RM 2 27.210 METERS 29137 |

HV2273|---------------------------------------------------------------------|

HV2273

HV2273 SUPERSEDED SURVEY CONTROL

HV2273

HV2273 NAD 83(1993)- 38 54 31.97719(N) 077 12 47.31441(W) AD( ) 2

HV2273 NAD 83(1986)- 38 54 31.97709(N) 077 12 47.32400(W) AD( ) 2

HV2273 NAD 27 - 38 54 31.57621(N) 077 12 48.38514(W) AD( ) 2

HV2273 NGVD 29 (??/??/??) 150.790 (m) 494.72 (f) ADJUSTED 2 0

HV2273

HV2273.Superseded values are not recommended for survey control.

HV2273.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.

HV2273.See file dsdata.txt to determine how the superseded data were derived.

HV2273

HV2273_U.S. NATIONAL GRID SPATIAL ADDRESS: 18SUJ0810408994(NAD 83)

HV2273_MARKER: DS = TRIANGULATION STATION DISK

HV2273_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT

HV2273_SP_SET: SET IN TOP OF CONCRETE MONUMENT

HV2273_STAMPING: PIMMIT 1958

HV2273_MAGNETIC: N = NO MAGNETIC MATERIAL

HV2273_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO

HV2273+STABILITY: SURFACE MOTION

HV2273

HV2273 HISTORY - Date Condition Report By

HV2273 HISTORY - 1958 MONUMENTED CGS

HV2273 HISTORY - 1960 GOOD CGS

HV2273 HISTORY - 1979 DESTROYED NGS

HV2273

HV2273 STATION DESCRIPTION

HV2273

HV2273'DESCRIBED BY COAST AND GEODETIC SURVEY 1958 (JCE)

HV2273'STATION IS LOCATED ABOUT 2.9 MILES NORTHWEST OF FALLS CHURCH,

HV2273'1.15 MILES SOUTHEAST OF TYSONS CROSSROADS AND ABOUT 250 FEET

HV2273'NORTHEAST OF STATE HIGHWAY NO. 7 (LEESBURG TURNPIKE). 40-1/2

HV2273'FEET WEST-NORTHWEST OF THE NORTHWEST SIDE OF PIMMIT SERVICE

HV2273'COMPANY WATER STANDPIPE, 22-1/2 FEET NORTH-NORTHEAST OF

HV2273'FENCELINE, AND 35-1/2 FEET EAST-NORTHEAST OF FENCE CORNER. THE

HV2273'MARK IS SET FLUSH AND THE DISK IS STAMPED, PIMMIT 1958.

HV2273'

HV2273'REFERENCE MARK NO. 1 IS 3 FEET EAST-SOUTHEAST OF A LOCUST TREE,

HV2273'AND 36 FEET SOUTH-SOUTHWEST OF A PERSIMMON TREE. THE MARK IS

HV2273'SET FLUSH AND THE DISK IS STAMPED, PIMMIT R.M. NO 1 1958.

HV2273'

HV2273'REFERENCE MARK NO. 2 IS 1 FOOT SOUTHEAST OF POWERLINE POLE,

HV2273'1 FOOT NORTHEAST OF FENCE CORNER, AND 10 FEET SOUTH-SOUTHEAST

HV2273'OF THE CENTERLINE OF ALLEY. THE MARK IS SET FLUSH AND THE

HV2273'DISK IS STAMPED PIMMIT R.M. NO 2 1958.

HV2273'

HV2273'TO REACH THE STATION FROM THE JUNCTION OF STATE HIGHWAY NO.

HV2273'123 AND STATE HIGHWAY NO. 7 AT TYSONS CROSSROADS, GO SOUTHEAST ON

HV2273'STATE HIGHWAY NO. 7 FOR 1.15 MILE TO LISLE AVENUE TO THE LEFT,

HV2273'TURN LEFT THENCE RIGHT ON STREET WHICH PARALLELS STATE HIGHWAY

HV2273'NO. 7 AND GO ABOUT 100 YARDS, TURN LEFT OVER CURBING (PURPOSED

HV2273'ALLEY). AND GO NORTHERLY PASSING BETWEEN HOUSES NUMBERED

HV2273'2408 AND 2410 AND GO 25 YARDS, THENCE RIGHT ABOUT 100 FEET

HV2273'AND STATION AS DESCRIBED.

HV2273'

HV2273'NO SUITABLE PLACE WAS FOUND TO SET AN AZIMUTH MARK. AND THERE

HV2273'ISNT ANYTHING VISIBLE FROM GROUND.

HV2273'

HV2273'HEIGHT OF LIGHT ABOVE STATION MARK 27 METERS.

HV2273

HV2273 STATION RECOVERY (1960)

HV2273

HV2273'RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1960

HV2273'1.4 MI NE FROM DUNN LORING.

HV2273'ABOUT 1.0 MILE NORTH ALONG DUNN LORING ROAD FROM THE POST

HV2273'OFFICE AT DUNN LORING, THENCE ABOUT 0.45 MILE SOUTHEAST ALONG

HV2273'STATE HIGHWAY 7, ABOUT 100 YARDS NORTHEAST OF HIGHWAY 7, 40 1/2

HV2273'FEET WEST-NORTHWEST OF THE NORTHWEST SIDE OF PIMMIT SERVICE

HV2273'COMPANY WATER STANDPIPE, 22 1/2 FEET NORTH-NORTHEAST OF FENCE

HV2273'LINE, 35 1/2 FEET EAST-NORTHEAST OF A FENCE CORNER, 89.3 FEET

HV2273'SOUTHEAST OF R M 2, AND SET IN TOP OF A CONCRETE POST FLUSH WITH

HV2273'THE GROUND.

HV2273

HV2273 STATION RECOVERY (1979)

HV2273

HV2273'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1979 (CLN)

HV2273'STATION MARK RECOVERED WITH ONLY THE STEM OF THE DISK

HV2273'REMAINING. REFERENCE MARK 1 AND REFERENCE MARK 2 RECOVERED IN GOOD

HV2273'CONDITION. A NEW SURFACE DISK WAS SET. A SHORTER DISTANCE OF 0.19

HV2273'FEET WAS NOTED TO RM 1 AND 0.04 FEET TO RM 2. THE ANGLE BETWEEN

HV2273'MARKS CHECKED WITH 1958 DATA.

 

*** retrieval complete.

Elapsed Time = 00:00:00

Edited April 11, 2005 by Z15

[evenfall]

Artman,

 

I concur with Mike and to add, this is on the Datasheet for the reset station:

 

HV9372.The orthometric height was determined by differential leveling

 

I would imagine they leveled it after resetting in 1979...

 

And there there was a long pause...

 

HV9372.and adjusted by the National Geodetic Survey in September 2004.

HV9372.No vertical observational check was made to the station.

 

September 2004 is why it was not in the Geocaching Database. It is said the station was set in 1979, But they only just adjusted the Data, and:

 

HV9372.No superseded survey control is available for this station.

 

Never had published the Data Prior to that? If so then it could not have had any published Vertical Data prior to 9/2004 If there were superseded data then it would have been in the geocaching database, as that was a snapshot of the database at the time.

 

The 1992 recovery makes it interesting though. I wonder if they located it but could not use it due to not having published data. yet they were able to submit the recovery to the PID... Hmmmm It makes one wonder what does not meet the eye.

 

Good Catch Artman :-)

 

Rob

[Z15]

Often things this like this fall between the cracks and it takes years to find it way thru to the right people.

 

 

There are 4 marks I reset in 2002, my last year on the job (retired) and they have not shown up in the db to this date. I am sure the boss has more pressing things to do than the worry about those 4 BM's and often got the impression he could care less. Some day someone will start looking for the info on the reset marks and then it will get done. Thing is, I had all the field work done and the paperwork. I can recal marks that we done many years in the past that the paperwork got lost in transit or it was thrown out when the person who job it was got sick and died. Then his job was never filled in an effort to cutback on state employees.