Sony SLT-A77 Digital Camera User Manual


 
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Trouble shooting/Others (Advanced operations)
GPS (SLT-A77V
only)
This system allows you to pinpoint
your exact location on the earth. The
GPS satellites are located in 6 orbits,
20,000 km above the earth. The GPS
system consists of 24 or more GPS
satellites. A GPS receiver receives
radio signals from the satellites, and
calculates the current location of the
receiver based on the orbital
information (almanac data) and travel
time of the signals, etc.
Determining a location is called
“triangulating.” A GPS receiver can
determine the location’s latitude and
longitude by receiving signals from 3
or more satellites.
As the positions of GPS satellites
vary constantly, it may take longer
to determine the location or the
receiver may not be able to
determine the location at all,
depending on the location and time
you use the camera.
“GPS” is a system for determining
geographic location by
triangulating radio signals from
GPS satellites. Avoid using the
camera in places where radio
signals are blocked or reflected,
such as a shadowy place
surrounded by buildings or trees,
etc. Use the camera in open sky
environments.
You may not be able to record
location information at locations or
in situations where radio signals
from the GPS satellites do not reach
the camera as follows.
– In tunnels, indoors or under the
shade of buildings.
– Between tall buildings or at
narrow streets surrounded by
buildings.
– In underground locations,
locations surrounded by dense
trees, under an elevated bridge, or
in locations where magnetic fields
are generated, such as near high
voltage cables.
– Near devices that generate radio
signals of the same frequency
band as the camera: near 1.5 GHz
band mobile telephones, etc.
On triangulating errors
If you move to another location
right after turning on the camera, it
may take a longer time for the
camera to start triangulating,
compared to when you stay in the
same place.
Error caused by the position of GPS
satellites
The camera automatically
triangulates your current location
when the camera receives radio
signals from 3 or more GPS
satellites. The triangulating error
allowed by the GPS satellites is
about 30 m (98 feet). Depending on
the environment of the location, the
triangulating error can be greater. In
this case, your actual location may
not match the location on the map
based on the GPS information.
Meanwhile, the GPS satellites are
controlled by the United States