Jackson Labs Micro-JLT GNSS, Руководство пользователя, Страница: 25 / 83

© 2019 Jackson Labs Technologies, Inc. 19
Micro-JLT GNSS™ User Manual
X, Y, and Z speed are individually given, and are independent of each other. An accuracy estimate in
centimeters per second is also given. The velocity data is time-stamped using the time-of-week with
a resolution of milliseconds.
Additionally, the number of accrued Leapseconds and GPS time of week is indicated in this message,
which allows proper calculation of GPS time from UTC time as indicated by other messages, as well
as proper handling of Leapsecond events.
Use the following format to generate the velocity vector every N seconds, with N in the interval
[0,255]:
GPS:XYZSPeed <int> [0,255]
The XYZSP string has the following data format:
$XYZSP VX VY VZ ... Leapseconds: aaaaa bbbbb ccccc ddd eeeeeeeee ff
where
aaaaa is the velocity in the x direction (cm/s),
bbbbb is the velocity in the y direction (cm/s),
ccccc is the velocity in the z direction (cm/s),
ddd is the speed accuracy estimate (cm/s),
eeeeeeeee is the GPS TOW in seconds,
ff is the current UTC leap second offset in seconds.
3.3.12 GPS:GPVTG <int> [0,255]
This command instructs the Micro-JLT GNSS™ to send the NMEA standard VTG message every N
seconds, with N in the interval [0,255]. The command is disabled until the GNSS receiver achieves a
first fix.
This command has the following format:
GPS:GPVTG <int> [0,255]
The GPVTG string has the following data format:
$GNVTG,x.x,T,x.x,M,x.x,N,x.x,K,m*[checksum]
The VTG output message header includes the talker ID for the currently enabled GNSS system or
systems as described in Section
3.3.4 .
3.3.13 GPS:GPZDA <int> [0,255]
This command instructs the Micro-JLT GNSS™ to send the NMEA standard ZDA message every N
seconds, with N in the interval [0,255]. The command is disabled until the GNSS receiver achieves a
first fix.
This command has the following format:
GPS:GPZDA <int> [0,255]
The GPZDA string has the following data format: