Leica Geosystems GPS System 500 - Technical Reference Manual - Manual (Page 63)

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2. Set-up and Connection Technical Reference Manual-4.0.0en
2.15 Measuring Antenna Heights
The height of the GPS Antenna above the point consists
of several components - the Height Reading, the Vertical
Offset and the Phase Center Eccentricities. When a
standard System 500 Antenna mounted on standard
System 500 accessories is selected, the only measure-
ment you will have to input is the Vertical Height (shown
as VR in the following section). When a pole is used, even
this value is automatically suggested by the Receiver as
2.00m (the height of the System 500 pole).
This means that for most operations, you will only need to
input the height measurement from the height hook or use
the default height measurement of 2.00m for the pole.
However, there may be cases when you need to calculate
the height components, such as when using non-Leica
accessories or Antennas or when not using a tripod or
pole.
It is also important to realize where the Antenna Heights
are measured to. This Datum is referred to as the Me-
chanical Reference Plane. This varies for different Anten-
nas. It is also the datum from which the Phase Center
Eccentricities are calculated.
Phase Center Eccentricities of Leica Antennas are
handled automatically by System 500. They will have to be
entered manually when using non-Leica Antennas. Advice
on how to create a new Antenna Type for non-Leica
Antennas is given in the Online Help of SKI-Pro (Antenna
Management).
Finally, the Antenna Height is sometimes calculated by
taking a slope distance from the point on the ground to the
outside edge of the Antenna. In this case, the Vertical
Height must be calculated using the Slope Height and a
Horizontal Offset.
Special care must be taken when using System 300 GPS
Antennas with a System 500 Receiver or when using the
AT501/502 GPS Antenna on the System 300 pole.