Leica GR30 - Example

Appendix B: NMEA Messages
257
Options:
GP = GPS only
GL = GLONASS only
GA = Galileo only
BD = BeiDou only
GN = Global Navigation Satellite System
• LVM = name of the message
hhmmss.ss
UTC time of velocity (Check official NMEA section 6.2.1)
mmddyy
UTC date of velocity
E.EEEE
East component of the receiver’s velocity, [m/s]
N.NNNN
North component of the receiver’s velocity, [m/s]
U.UUUU
Up component of the receiver’s velocity, [m/s]
v.v
Variance of the East velocity component, [m2/s2]
v.v
Variance of the North velocity component, [m2/s2]
v.v
Variance of the Up velocity component, [m2/s2]
c.c
Covariance between the East and North velocity components, [m2/s2]
c.c
Covariance between the East and Up velocity components, [m2/s2]
c.c
Covariance between the Up and North velocity components, [m2/s2]
q.q
3D velocity Component Quality (CQ
[1]
), [m/s]
xx
Number of satellites whose observations have been used to calculate the velocity values
*hh
Checksum
<CR>
Carriage Return
<LF>
Line Feed
[1]
CQ stands for Component Quality and is given by the sum of the standard deviation and of the contribution of empirical assumptions.
Therefore, CQ accounts for measurements noise, environmental conditions (e.g. tropospheric and ionospheric delay) and for the
influence of the different constellations on the components.
Example
User defined Talker ID = GN
$GNLVM,113805.50,030215,0.0011,0.0021,0.0015,0.0023,0.0040,0.0092, 0.00012,0.00015,0.00035,0.043561,19*47
B15: LDM - Leica Displacement Measurement
Syntax
$--LDM,hhmmss.ss, mmddyy, hhmmss.ss , mmddyy, E.EEEE, N.NNNN, U.UUUU, v.v, v.v, v.v, c.c , c.c , c.c, q.q, xx, a, a, a
*hh<CR><LF>
Description of fields
Field
Description
$--LDM
Header including talker ID:
• -- = alphanumeric characters identifying the talker