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5.4.2 ALTAID – Set The Altitude Aiding Mode
Sets or disables the altitude aiding mode, where the navigation is assisted by using the given
altitude value or an altitude value from a previous fix. Altitude aiding enables a navigation
fix with fewer than four satellites, and as a matter of fact altitude aiding is used only if there
are four or less satellites visible. Note that the aided altitude is used as an additional
observation and the altitude is still calculated, not fixed to the given or aided altitude.
Altitude aiding commands can be given before starting or during the navigation. The altitude
aiding mode is reset to “no altitude aiding” when navigation is stopped.
By default, the altitude aiding mode is disabled.
$PFST,ALTAID,<mode>,<altitude>
<mode>
A numeric value indicating the new altitude aiding mode:
0 : No altitude aiding (default)
1 : Altitude hold mode: Use an altitude from the previous fix
2 : External altitude mode: Use constant altitude given in the <altitude>
parameter.
<altitude>
Constant altitude in meters above the sea level, used in altitude aiding
mode 2. This parameter is ignored in other modes.
The constant altitude is subject to the altitude limits as defined in
the command
$PFST,SETLIMITS
5.4.3 SETLIMIT – Set Limits For Altitude, Velocity And Acceleration
Sets the upper limits for altitude, velocity and acceleration parameters that the PCM3292
navigation subsystem accepts for a valid fix. Setting realistic, lower-than-default limits for
these parameters hastens finding a valid navigation fix.
$PFST,SETLIMIT,<altitude>,<velocity>,<acceleration>
<altitude>
Maximum value for altitude (meters).
<velocity>
Maximum value for velocity (m/s).
<acceleration> Maximum value for acceleration (m/s2).
The PCM3292 module checks the given parameters values against fixed upper limits for
each of these parameters (same as the factory defaults, see below), thus the user cannot set
the parameters beyond these values.
If necessary, the <acceleration>, or <velocity> and <acceleration> parameters may be
omitted. If all the three parameters are omitted, the command displays the current maximum
limit values.
Содержание PCM-3292
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