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Details for Benchmark: HT0026

N 37° 46.217 W 122° 14.233 (NAD 83)

Altitude: 12.9

Coordinates may not be exact. Altitude is VERTCON and location is SCALED. (more info)

Location:
In ALAMEDA county, CA View Original Datasheet
Designation:
RV 1
Marker Type:
NGS Benchmark
Setting:
setting not listed - see description
Stability:
Mark of questionable or unknown stability.

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Did not find marker. There is a spot where a merker may have been removed.

Documented History (by the NGS)

Unknown by CA-001 (MONUMENTED)
01/01/1951 by NGS (GOOD)
DESCRIBED BY NATIONAL GEODETIC SURVEY 1951 AT ALAMEDA. AT ALAMEDA, AT THE INTERSECTION OF PARK STREET AND BLANDING AVE. AT THE PARK STREET BRIDGE OVER THE CHANNEL, IN THE TOP OF THE SOUTHWEST END OF THE CONCRETE BASE OF THE SOUTHEAST GUARD RAIL, 23.9 FEET SOUTHEAST OF THE CENTER LINE OF THE STREET, AND ABOUT 1.0 FOOT HIGHER THAN THE STREET.
01/01/1963 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1963 RECOVERED IN GOOD CONDITION.
01/01/1984 by USPSQD (GOOD)
RECOVERY NOTE BY US POWER SQUADRON 1984 RECOVERED IN GOOD CONDITION.
01/01/1987 by USPSQD (MARK NOT FOUND)
RECOVERY NOTE BY US POWER SQUADRON 1987 (RAS) MARK NOT FOUND.
10/11/1988 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1988 RECOVERED IN GOOD CONDITION.

Control Text

  • The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
  • The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.) The vertical order pertains to the superseded datum.
  • The geoid height was determined by GEOID99.

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