Toutes les données d’étalonnage sont maintenues par le National Geodetic Survey : ChokeRing 701945

Les antennes de ce type au sein du parc étaient :

Géométrie

Ci-après un extrait d’un courriel échangé en 2002 avec Michael Morrison (Geosciences Lab/National Geodetic Survey/NOS/NOAA) :

Regarding the various revisions of the Ashtech 701945 antenna :

 Ashtech 701945 Rev.A
 Ashtech 701945 Rev.B
 Ashtech 701945 Rev.C

These three antennas are all mechanically and electrically identical.
The changes made to Rev.B and Rev.C had to do with the documentation
provided with the antenna, nothing else. Thus, the L1 and L2 phase
centers ; the elevation corrections ; and the associated RMS values for
all three antennas would be the identical.

The use of "01" and "02" is Ashtech’s contribution to the confusion.
For this particular model, Ashtech 701945-01 is the designation for
this antenna when it is sold WITH the associated radome. When it is
sold WITHOUT the radome, it is called Ashtech 701945-02. We only tested
the version without the radome. So if you have both 701945-01 and
701945-02 antennas, they are identical. It is just that at some point
in time, there was a radome associated with the "01" antenna.