136
HDT: True Heading
$GPHDT,f1,T*cc
HPR: True Heading
This message delivers either pitch OR roll angles, not both at
the same time, depending on how the antennas are installed.
$PASHR,HPR,m1,f2,f3,f4,f5,f6,d7,d8,d9,f10*cc
Parameter
Description
Range
f1,T
Last computed heading value, in degrees
“T” for “True”.
0-359.99
*cc
Checksum
*00-*FF
Parameter
Description
Range
m1
UTC time of attitude data (hhmmss.ss).
000000.00-
235959.99
f2
True heading angle in degrees.
000.00-359.99999
f3
Pitch angle in degrees.
±90.00000
f4
Roll angle in degrees.
±90.00000
f5
Carrier measurement RMS error, in meters.
Full range of real
variables
f6
Baseline RMS error, in meters.
(=0 if baseline is not constrained)
Full range of real
variables
d7
Integer ambiguity:
• 0: Fixed
• >0: Float
0, >0
d8
Attitude/heading mode status:
• 0: Operation with fixed baseline length
• 1: Calibration in progress
• 2: Flex (flexible) baseline mode ON
0, 1, 2
d9
Character string of the type “y.xxx” defined
as follows:
• “y” refers to the antenna setup:
y=0: no length constraint is applied
y=1: heading mode (one vector)
y=2: attitude mode (2 vectors)
y=3: attitude mode with 3 or more vectors
• Each “x” (0 to 9) represents the number of
Double Differences (DD) used in the corre-
sponding baseline.
If this number is greater than 9, then “9” is
reported.
If there are only 2 vectors, the last x is “0”
Double differences refer to the very last inte-
ger second time-tagged epoch.
y.xxx
f10
PDOP corresponding to vector V12, as com-
puted for the very last integer second (time-
tagged epoch). Empty if PDOP unknown.
*cc
Checksum
*00-*FF
