Precision Geodesy via Radio Interferometry.
Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources, most to within 1 arc second, and allowed the hydrogen maser clocks at the two sites to be synchronized a posteriori with an uncertainty of only a few nanoseconds.
Hinteregger
H F
HF
Shapiro
I I
II
Robertson
D S
DS
Knight
C A
CA
Ergas
R A
RA
Whitney
A R
AR
Rogers
A E
AE
Moran
J M
JM
Clark
T A
TA
Burke
B F
BF