3 kinematic surveys, Surveying with gps – Leica Geosystems GPS Basics User Manual

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GPS Basics -1.0.0en

Surveying with GPS

5.1.3 Kinematic Surveys

The Kinematic technique is typically

used for detail surveying, recording

trajectories etc., although with the advent

of RTK its popularity is diminishing.
The technique involves a moving Rover

whose position can be calculated

relative to the Reference.
Firstly, the Rover has to perform what is

known as an initialization. This is

essentially the same as measuring a

Rapid Static point and enables the post-

processing software to resolve the

ambiguity when back in the office. The

Reference and Rover are switched on

and remain absolutely stationary for 5-20

minutes, collecting data. (The actual

time depends on the baseline length

from the Reference and the number of

satellites observed).
After this period, the Rover may then

move freely. The user can record posi-

tions at a predefined recording rate, can

record distinct positions, or record a

combination of the two. This part of the

measurement is commonly called the

kinematic chain.

A major point to watch during kinematic

surveys is to avoid moving too close to

objects that could block the satellite

signal from the Rover receiver. If at any

time, less than four satellites are tracked

by the Rover receiver, you must stop,

move into a position where 4 or more

satellites are tracked and perform an

initialization again before continuing.

Initialization is performed

from the Reference to the

Rover.

The Rover can then move.

Positions can be recorded

at a predefined interval...

...and also at distinct

points if required.

Kinematic on the Fly
This is a variation of the Kinematic

technique and overcomes the require-

ment of initializing and subsequent re-

initialization when the number of

observed satellites drops below four.
Kinematic on the Fly is a processing

method that is applied to the measure-

ment during post-processing. At the

start of measurement, the operator can

simply begin walking with the Rover

receiver and record data. If they walk

under a tree and lose the satellites,

upon emerging back into satellite

coverage, the system will automatically

reinitialize.