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10 metres and less
We are
one of Australia's PREMIER Garmin suppliers.
All
handheld GPS, regardless of brandname, achieve the same
accuracy. The same goes for aviation GPS, and GPS mounted
in boats. This is because the technology is bounded by
price considerations for the consumer market.
WAAS areas
(not in Australia) can give greater accuracy.
Haicom CF
and Bluetooth GPS can be used with PDA and computers,
and give similar accuracy. These are suitable
for some GIS field data capture.
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down to 1 metre
Use a wide area DGPS service
with some hand-held or mounted Garmin GPS.
GIS PDA
attributing software works with hardware such as the Leica
GS5
or the JRC set
in some areas.
Use the Omnistar
DGPS for
Australia and world wide coverage, using some Garmin
handheld or mounted GPS.
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1
metre down to 0.4 metre (40 cm)
Accuracies
down to 0.4m on a handheld computer, or laptop, with appropriate
mapping or GIS software.
Looking for
accuracy of 1 metre or less? - Use the Leica
GS50 and GS20 system or a
PDA or rugged PDA, laptop or tablet PC connected to
sub-metre Hemisphere
DGPS.
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100
mm (10 cm)
Accuracies
down to 0.1m on a handheld computer, or laptop, with appropriate
mapping or GIS software.
The Omnistar
High Precision system means that field GIS personnel can use any PDA,
laptop computer or tablet, and capture data to an accuracy
of 1 decimetre or less.
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20 mm
Surveyors usually need 1-2cm,
to define real property boundaries, or to set out engineering works.
This requires sophisticated data computing techniques. In a relatively
small market, the prices are way above consumer level GPS.
Equipment
costs about $15,000+ for a computer result system, or at least
$50,000+ for a real time radio link system, with handheld data
recorders.
A
word on GPS accuracies
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It does not matter what you pay for a
GPS - accuracy is the same, unless you use special facilities
such as WAAS or DGPS. Most GPS display the accuracy figure
in metres, on one of the navigation screens. The user should
keep an eye on this, especially after first switching on
the GPS. In the inital few minutes, accuracy could start
at 300 metres, then drop rapidly to 20 metres, and then
to 10. Marking a point while accuracy is shown at 300 metres,
will obviously mis-position that point for later finding.
In an urban street
bounded by tall buildings, or in a heavily timbered forest,
you may get large
errors. Accuracy may go to 30 metres, or the GPS may
not be able to work at all. This is because some of the
satellites are hidden from the GPS. The more satellites
in view, the better your position fix. Johnny Appleseed
GPS can always give you the right advice regarding the
correct operation of your GPS, and how to maximize the
benfits of GPS for your particular use.
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A
quick view of our Product range
GPS for recreation, aviation,
sciences and public services
SOFTWARE for GPS
IN-CAR Navigation
GPS MAPPING
GPS for Geographic Information Systems
EPIRBS
Fishfinders and Sounders.
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Johnny Appleseed GPS