Reoccupation

 This technique is regarded as a third from of static surveying or as a pseudo kinematic procedure it is based on repeating the survey after a time gap of one or two hours in order to make use of the change in receiver/satellite geometry to resolve the integer ambiguities 

The master receiver is once again positioned over a known point whilst the roving receiver visits the unknown points for a few minutes only after one or two hours the roving receiver returns to the first unknown point and repeats the survey there is no need to track the satellites whilst moving from point to point this technique therefore makes use of the first few epochs of data and the last few epochs that reflect the relative change in receiver/satellite geometry and so permit the ambiguities and coordinate differences to be resolved 

Using dual frequency data gives values comparable with the rapid static technique due to the method of changing the receiver/satellite geometry it can be used with cheaper single frequency receivers ( although extended measuring times are recommended ) and a poorer satellite constellation 

Kinematic positioning 

The major problem with static GPS is the time required for an appreciable change in the satellite/receiver geometry so that the initial integer ambiguities can be resolved 

However if the integer ambiguities could be resolved ( and constrained in a least squares solution ) prior to the survey then a single epoch of data would be sufficient to obtain relative positioning to sub centimetre accuracy 

This concept is the basis of kinematic surveying 

It can be seen from this that if the integer ambiguities are resolved initially and quickly it will be necessary to keep lock on these satellites whilst moving the antenna 

Stop and go surveying 

As the name implies this kinematic technique is practically identical to the previous one only in this case the rover stops at the point of detail or position required ( Figure 9.17 ) 

The accent is therefore om individual points rather than a trajectory route so data is collected only at those points 

Lock must be maintained though the data observed when moving is not necessarily recorded 

This method is ideal for engineering and topographic surveys