Preliminary GPS (RTK values) from Tom Reiss, e-mailed 10/07/2009.
I collected 15-20 minutes of raw data for post processing so these values may change a little.
(We did not survey the two reflector positions)
AST1 (Aerial Survey Target #1)
Location: concrete support structure of Hetch-Hetchy pipeline. Center of concrete mass
Latitude: 37d 29m 22.86394s
Longitude: 122d 07m 33.60521s
O. Ht: 4.532m
HHBM (Hetch-Hetchy BenchMark)
Location: concrete support structure of Hetch-Hetchy pipeline. North-east corner of concrete mass
Latitude: 37d 29m 22.90750s
Longitude: 122d 07m 33.56190s
O. Ht: 4.587m
They were obtained using a GPS receiver on RAV3 (Towill #3) with the folowing coordinates:
Latitude: 37d 29m 55.62946s
Longitude: 122d 07m 42.47334s
O. Ht: 2.438m
Source Coordinate System: Coordinate System: NAD83(NSRS2007)
Datum: NAD83 (National Spatial Reference System 2007)
Ellipsoid: GRS 1980
Semi-major axis(meters): 6378137.00000000
Semi-minor axis(meters): 6356752.31414036
Eccentricity: 0.08181919104281582
Eccentricity Squared: 0.0066943800229007921
Inverse Flattening: 298.257222101
Inverse Flattening Definitive: True
Vertical Reference: NAVD88 via NGS Height Mod Project (on NAD83)
Vertical Datum: North American Vertical Datum of 1988
