How is the antenna height measured?
The height is measured vertically (NOT the slant height) from the mark to the ARP of the antenna.
The height is measured in meters.
The ARP is almost always the center of the bottom-most, permanently attached, surface of the antenna.
See GPS Antenna Calibration for photo’s and diagrams that show where the ARP is on most antennas.
If 0.0000 is entered for the height, OPUS will return the position of the ARP.