Leica Geosystems GPS System 500 - Getting Started with Static and Kinematic Surveys - Manual (Page 37)

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Static and Kinematic Surveys-2.0.0en Kinematic and Stop & Go surveying
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Kinematic and Stop & Go surveying - using static initialization
on a baseline not longer than 3 - 5
km will be sufficient to resolve ambi-
guities in post-processing. Once this
static initialization is accomplished
the GPS antenna can be moved and
other points of interest can be
occupied with only a few seconds of
measurements. High accuracy's will
be maintained as long as satellite
signal reception is not interrupted, for
instance by obstructions.
As soon as a complete loss of signal
lock occurs - this means that the
signal of satellites is interrupted such
that less than 4 satellites remain
unaffected - the high accuracy of
results is lost and ambiguities must
be reestablished first. This means
that in such a case another static
initialization is required.
Kinematic and Stop & Go surveying
is an efficient way of measuring many
points quickly and efficiently, provided
the following criteria are met:
• Distances between the reference
receiver and the rover is fairly
short, ideally less than 3 km.
Baselines above 5 km should be
avoided if possible.
• The surveying area is fairly open
with not many obstructions
between points. Obstructions will
cause satellite signal interruptions
which can cause complete losses
of lock. In such cases static re-
initializations become necessary
which slow down the field
operation.
Introduction and general
comments
Kinematic measurements will provide
the trajectory of a moving antenna. If
for instance raw data is logged every
second, the result will be 3 dimensio-
nal coordinates for every second the
antenna was moved.
While kinematic measurements are
only time related but not point
related, Stop & Go measurements
deliver coordinates for discrete points
which are occupied for a short period
of time, usually a few seconds.
In order to achieve position
accuracy's on the centimeter level in
a moving environment the so called
"ambiguities" must be resolved. The
safest way is to start Kinematic and
Stop & Go surveys with a static
initialization. Usually about 5 minutes
of dualfrequency static observations