The VLBA station is located approximately 180 miles southwest of El Paso, Texas on the southern edge of the Fort Davis mountains and 8 miles northwest of the town of Fort Davis. A fixed 26-meter polaris antenna (HRAS 085), located at the George R. Agassiz station (GRAS), was operational until 1991. It has since been dismantled.

The VLBA antenna is 300 meters southeast of where HRAS was located.

Measurements supporting the determination of plate motion, plate stability, polar motion/earth rotation, regional deformation, and intercomparison of measurement techniques.

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4010-S 1993
0.457 Meter Diameter Stainless Steel Plate
Fort Davis VLBA Site GPS Station Mark JPL 4010-S 1993
GPS

N 30° 38' 06.26916"
W 103° 56' 36.99422"
1617.13 meters
1594.436 meters
ATSC / 12-DEC-97
IERS / ITRF94
NGVD 1927

ATSC

None

NONE (VLBA Reference Pt.)
HRAS 85

The station is located approximately 180 miles southeast of El Paso, Texas in the Davis Mountians and 8 miles northwest of the town of Fort Davis.

The station mark is a punchmark in the center of an etched triangle on the top of a 0.457 meter diameter stainless steel plate. The plate is set flush in the top of a 0.762 meter diameter concrete monolith that projects 0.5 meters above the ground. The stainless steel plate is etched "Fort Davis VLBA Site GPS Station Mark JPL 4010-S 1993 NASA FLINN Site North American High Precision Fiducial Network Blewitt and Clark Space Geodetic Pioneers JPL/GSFC Collaboration".

The mark is set approximately 33 meters North of a wood post/wire fenceline and 50 meters East of a large dirt berm that extends around the Northeast perimeter of the NRAO VLBA antenna fenceline.

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7216
Intersection of polar axis and plane containing
declination axis
None
85-Foot Fixed VLBI Antenna

N 30° 38' 12.18811"
W 103° 56' 50.11324" meters
1616.84 meters
1595.125 meters
ATSC / 12-DEC-97
IERS ITRF94 (1993)
NGVD 1929

The antenna is also referenced as HRAS 085. For monument listed below see the McDonald site information. The antenna was dismantled in 1991.

7080 1988
MOBLAS 1979
NONE (LURE 107 1985)
7850 1988
7851 1988
TLRS 7897
HARVARD RM 5 1980
HARVARD 1977
HARVARD RM 3 1977
HARVARD RM 4 1977
HARVARD RM 6 1977

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7613
Intersection of Elevation & Azimuth Axes
None
25-Meter VLBA Antenna

N 30° 38' 06.08864"
W 103° 56' 41.32055"
1628.16 meters
1606.439 meters
ATSC / 16-DEC-97
IERS ITRF94 (1993)
NGVD 1929

JPL 4010-S 1993
-------
NONE-HRAS REF PT.
HARVARD NO. 5 (1977)
FT DAVIS VLBA RM1
FT DAVIS VLBA RM2
FT DAVIS VLBA RM3
HARVARD 1977

JPL 4010-S 1993
FT DAVIS VLBA RM1
FT DAVIS VLBA RM2
FT DAVIS VLBA RM3

The station is located approximately 180 miles southeast of El Paso, Texas on the southern edge of the Davis mountains, and 8 miles northwest of the town of Fort Davis, Texas.

The station mark is a point represented by the perpendicular intersection of a plane through the elevation axis with the azimuth axis of the NRAO VLBA (Very Long Baseline Array) antenna. The point is not accessible and cannot be occupied. No survey disk or mark designates the point. It should be noted that the antenna elevation axis is offset by 2.134 meters (7 feet) from the antenna azimuth axis.

Reference mark 1 is a punch mark in the center of the rounded top of a 0.012 meter diameter stainless steel rod. It is set approximately 0.3 meters below the ground surface in a greased 0.025 meter diameter pvc pipe. The mark and greased pvc pipe are set in the center of a 0.14 meter diameter pvc pipe that is held in place with concrete. An aluminum logo cover has been cemented to the top of the 0.14 meter diameter pvc pipe and covers the mark. The cover is set flush with the ground surface. The aluminum cover is stamped "FT. DAVIS VLBA RM1 JAN 90". The mark is set approximately 22.5 meters southeast of the centerline of a gravel road and is located at a distance of 109.4 meters and at a geodetic azimuth of 07 degrees from SGP Station 7613.

Reference mark 2 is a standard NASA-GSFC brass disk set flush and epoxied into bedrock approximately 0.4 meters below the ground surface. The disk is stamped "FT. DAVIS VLBA RM2 JAN 90". The disk is set in the center of a 0.14 meter diameter pvc pipe that is held in place with concrete. An aluminum logo cover has been cemented to the top of the pvc pipe and is flush with the ground surface. The mark is set approximately 1.4 meters north of a wooden pole/barbed wire fenceline, and is located at a distance of 141.4 meters and at a geodetic azimuth of 99 degrees from SGP Station 7613.

Reference mark 3 is a standard NASA-GSFC brass disk set flush and epoxied into bedrock approximately 0.4 meters below the ground surface. The disk is stamped "FT. DAVIS VLBA RM3 JAN 90". The disk is set in the center of a 0.14 meter diameter pvc pipe that is held in place with concrete. An aluminum logo cover has been cemented to the top of the pvc pipe and is flush with the ground surface. The mark is set approximately 20 meters northeast of the corner of a wooden pole/barbed wire fenceline and is located at a distance of 120.1 meters and at a geodetic azimuth of 235 degrees from SGP Station 7613.

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7900
Standard Brass Reference Monument
Harvard RM 5 1977
Mobile VLBI

N 30 38' 08.81660"
W 103 56' 50.37055"
1605.104 meters
1583.384 meters
ATSC / 16-DEC-97
IERS ITRF94 (1993)
NGVD 1929

This reference monument was occupied by a mobile VLBI during a special VLBI experiment in October 1988.

CDP STATION 7080 1988
MOBLAS CDP 7086 (1979)
NONE (LURE 107 1985)
CDP STATION 7850 (1988)
CDP STATION 7851 (1988)
TLRS 7897
HARVARD 1977
HARVARD RM 3 1979
HARVARD RM 4 1980
HARVARD RM 6 1980