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As soon as GPS signal is acquired and tracked, the
HI-204E will transmit valid navigation information
through its serial interface. The navigation data
contains following information:
• Receiver position in latitude, longitude, and altitude
• Receiver velocity
• Time
• DOP error-magnification factor
• GPS signal tracking status
The HI-204E will perform 3D navigation when four or more
satellites are tracked. When three or fewer satellites are
tracked, altitude-hold is enabled using the last computed
altitude and 2D navigation mode is entered.
With signal blockage or rising and setting of the satellites,
where a change in satellite constellation used for position fix
occurred, large position error may result. The HI-204E
incorporates a proprietary algorithm to compensate the
effect of satellite constellation change, and maintains an
accurate smooth estimate of the receiver position, velocity,
and heading.
