Trimble Outdoors 5700 - Manual (Page 98)

7 Static and FastStatic Surveying
8 2 5700 GPS Receiver User Guide
Appl
icatio
ns
7.3
FastStatic Surveying
Like Static surveying, FastStatic surveying requires simultaneous
observations of 4 or more satellites for a period of 8 or more minutes.
FastStatic surveying yields baseline components with a precision of
±0.5 mm + 1 ppm.
FastStatic surveying is similar to Static surveying in that data is
logged only while the receiver is stationary and occupying a point. As
the receiver moves from each point to another point in the survey, no
data is logged, because the 5700 receiver is turned off during this
period. The manner in which the data is treated by the baseline
processor is also similar.
FastStatic surveying differs from Static surveying in the fact that less
data is collected. The occupation time is shorter, resulting in fewer
measurements for the baseline processor to use. Therefore, the
expected baseline precision is not as high for FastStatic as it is for
Static surveying. A less important distinction between FastStatic and
Static surveying is the potential for logging more than one occupation
within a single data file.
FastStatic surveying requires at least two receivers logging common
data from two different locations. The length of time the receivers log
data depends on:
• the number of satellites being tracked
• the geometry of the satellites being tracked (PDOP)
• the quality of the data being logged
Items affecting the quality of data are:
• cycle slips
• multipath
• radio frequency (RF) interference
Cycle slips are interruptions of data logging on one or more satellites.
Multipath is the reflection of the satellite signal off nearby surfaces,
such as the roof of a car.