states of the receiver. During attempting to a position fix, the receiver needs to lock
on to at least 3 satellites and, uses the signal can be received as well as the data of
latest position stored in the receiver
’
s digital memory in order to compute the
location of the device.
Environmental factors that influence the position accuracy and TTFF including such
as
Tall buildings,
Narrow street and passageway,
Protection film on glass,
Heavy foliage,
Large cliffs,
and other obstructions where the satellite signals may blocked, and, poor satellites
geometry situation. Initial state of the receiver, means latest status in memory of the
receiver, may mainly determine the time of TTFF. Position can be quickly fixed within
only 10 seconds from a hot-start state and needs 45 seconds typically from a cold-
start state. Or, might need at least 3 to 5 minutes from a completely restart-state, for
example, flying a distance over 500 kilometers from initial origin.
BGP-2000 uses the satellite signals to calculate an exact geodetic location through
triangulation method, contained in 10 meters CEP accurateness devoid of Selective
Availability (SA), which is good enough for general location awareness purposes. The
position data is then converted within the receiver to latitude and longitude
coordinates, which is usually provided in the geodetic datum on which GPS is based
(WGS84). Position offsets of hundreds of meters or much more can result from using
the wrong datum.
In addition to datum used, there are number of positioning errors can occur, limiting
accuracy. The major errors including satellites orbiting error, poor satellites
geometry, multi-path signals, atmospheric delay and receiver clock timing.
5. Caution and Warning
BGP-2000 contains a rechargeable Ni-MH battery which supplies the power for the
of GPS and Bluetooth operation. Care and caution must take into account are :
