DMU380SA Series
User’s Manual
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Doc# 7430-0026 Rev.01
Page 65
Hard and Soft Iron Values
8.6
These fields allow access to hard iron bias and soft iron scale ratio values for
magnetometer alignment (See Table 27):
Table 27.
DMU380 Magnetic Alignment Parameters
Field Name
Field ID
Format
Scaling
Units
X Hard Iron Bias
0x0009
I2
20/2^16
Gauss
Y Hard Iron Bias
0x000A
I2
20/2^16
Gauss
Soft Iron Scale Ratio
0x000B
U2
2/2^16
-
The hard iron bias values are scaled from [-1,1] Gauss. These values are subtracted from
the tangent plane magnetometer vector before heading is calculated. The soft iron scale
ratio is scaled from [0,2) and is multiplied by the tangent plane x magnetometer value
before heading is calculated.
Heading Track Offset
8.7
This field is used to set the offset between vehicle heading and vehicle track to be used
by the navigation mode filter when no magnetometer heading measurements are available
(See Table 28).
Table 28.
DMU380 Heading Track Offset
Field Name
Field ID
Format
Scaling
Units
Heading Track Offset
0x000C
I2
2*pi/2^16
[360°/2^16]
Radians (heading-track)
[°]
