Gintec G20M - Measure Antenna Height

7
c. Repeat the above a & b steps for each 90
0
rotations of the instrument and check
whether the bubble is correctly centered in all directions.
4.1.3 Measure antenna height
The antenna height must be measured when we use G20M to collect static data or use
it as base station. It’s the “a” show in below Figure 4-5, the height from ground
measured point to phase center, only get this height can we know coordinate of the
ground measured point. There are 3 measuring methods to get the antenna height:
(1) Slant height
Measure the distance from the ground measured point to the middle of mainframe scale
mark. It’s the “d” shown in Figure 4-5.
(2) Pole height
Measure the distance from bottom of device to ground directly. It’s the vertical height
“b” shown in Figure 4-5.
(3) Measuring plate
Measure the distance ground measured point to the upper edge of plate. It’s the “c”
shown in Figure 4-5.
Choose either one measuring method from above. Use measure tape measure the height
you choose. Input the height in software. Then you can get the height from ground to
phase center. The formula is as below:
a=b+L1
b=
22
kc
−
b=
22
Rd −
－H
Figure 4-5 (Measure Antenna Height)