Measurement methods

1

Tripod and Tribrach eBubble

Until Tilt Compensation this has been the static control measurement of choice for the highest confidence. This is done on a surface and the eBubble can be used to remove all projected values directly below the Antenna Phase Center (APC) of the receiver.

2

Plumb pole routine on a pole

The Plumb Pole routine centers the pole tip to be directly under the APC when level. This routine also gets the pitch and roll values to be near 0 when level. This routine enables tilt measurements while tilted on the pole as it combines the Inertial Measurement Unit (IMU) observations with the GNSS observations and calculates a pole tip position.

3

Calibrated eBubble on a pole

Due to manufacturing of survey poles and the multiple joints, a highly calibrated ebubble is degraded by the pole it is attached too. This is easily checked by measuring a point in multiple directions and seeing the effects of the “crooked pole”.

4

Tilt compensation without PPR

Running Tilt Compensation without the Plump Pole routine results in points being taken with the default IMU mounting angles and thus the receiver is not correcting and projecting the pole tip position. This error, while it primarily affects the horizontal position, has the potential to affect the vertical when tilted and rotated.

5

Rod bubble

This method is the primary use case since it has been around the longest but has potential for large errors. This is due to the manufacturing of the poles and the multiple joints that make them crooked. Also the maintenance and use of the poles while observing are often overlooked as the source of errors when high precision horizontal positions are required.