2003-09-01

AA4251 - HPGN-D CA 10 GK

Published Details for Benchmark: AA4251
N 37° 38.317
W 120° 48.608 (NAD 83)
Altitude: 152

Coordinates may not be exact. Altitude is GPS OBS and location is ADJUSTED.

Location: In STANISLAUS county, CA View Original Datasheet
Designation: HPGN-D CA 10 GK
Marker Type: survey disk
Setting: aluminum alloy rod
Stability: Probably hold position/elevation well.

Documented History (by the NGS)
01/01/1993 by CADT (MONUMENTED)
DESCRIBED BY CALTRANS 1993 (PDG) THE STATION IS LOCATED ON THE SOUTH SIDE OF STATE HIGHWAY 132 (YOSEMITE BLVD.) AT THE WATERFORD CANAL, ABOUT 10 MI (16.1 KM) EAST OF THE CITY OF MODESTO AND ABOUT 3 MI (4.8 KM) WEST OF THE CITY OF WATERFORD. TO REACH THE STATION FROM THE INTERSECTION OF STATE HIGHWAY 132 (YOSEMITE BLVD.) AND A SIDE ROAD RIGHT, COUNTY ROUTE J7 (SANTA FE ROAD TO THE SOUTH) IN EMPIRE, ABOUT 5 MI (8.0 KM) EAST OF MODESTO, GO EAST ON HIGHWAY 132 (YOSEMITE BLVD.) FOR 3.0 MI (4.8 KM) TO THE INTERSECTION OF COUNTY ROUTE J14 (ALBERS ROAD TO THE NORTH AND GEER ROAD TO THE SOUTH). CONTINUE EAST ON HIGHWAY 132 FOR 2.1 MI (3.4 KM) TO THE WATERFORD CANAL (BRIDGE NO. 38-57) AND THE STATION ON THE RIGHT AT POST MILE 25.2. THE STATION IS A SURVEY DISK ENCASED IN PVC PIPE WITH ACCESS COVER SET IN CONCRETE FLUSH WITH THE GROUND. IT IS 40.6 FT (12.4 M) SOUTH OF THE CENTERLINE OF HIGHWAY 132, 2.7 FT (0.8 M) WEST OF THE WEST END OF A CONCRETE HEADWALL, AND 2.0 FT (0.6 M) WEST OF A CARSONITE WITNESS POST. THE STATION WAS OCCUPIED AS PART OF A CALIFORNIA HPGN DENSIFICATION SURVEY.

Found Details for Benchmark: AA4251
N 37° 38.317
W 120° 48.609
Altitude: 139

Found it at 16:50, 01 September 2003 as described and in good condition, with exception that the cover is now missing.

Very accurate coordinates. Caltrans uses survey grade static GPS equipment when performing their High Precision Geodetic Network (HPGN) surveys. Much more accurate than any hand-held GPSr.

Original NAD83 coordinates were located about 6 feet easterly of the found WGS84 coordinates. WGS84 coordinates for the mark found by 3.5 minute occupation with 6 strong satellites and 0 WAAS satellites.


Benchmark detail.


The benchmark and the Magellan.


The view easterly showing the canal sign and the witness post.


The view southerly, down the canal.


The view westerly, showing the neighboring store. The mark is at the end of the headwall.

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