105
 
1.  Connect power and a laptop to the system. 
2.  Commit a default setting to the RT using NAVconfig, then run NAVdisplay. 
3.  Click the Calibration button, then select the Navigation tab and scroll to view the 
x, y, and z angular rates (values 30 to 32). 
4.  Rotate the RT  according to Table 38 and check the angular rate measurements 
occur. 
5.  With the unit stationary, check all the angular rates are within ±5°/s. (In general 
they will be within ±0.5°/s, but the algorithm in the RT will work to specification 
with biases up to ±5°/s). 
Table 38. Angular rate measurement specifications 
Orientation 
x  y  z 
Angular rate measurement 
+ve  Zero  Zero  The x-axis should indicate positive rotation, others are 
small. 
–ve  Zero  Zero 
The x-axis should indicate negative rotation, others are 
small. 
Zero  +ve  Zero  The y-axis should indicate positive rotation, others are 
small. 
Zero  –ve  Zero  The y-axis should indicate negative rotation, others are 
small. 
Zero  Zero  +ve 
The z-axis should indicate positive rotation, others are 
small. 
Zero  Zero  –ve  The z-axis should indicate negative rotation, others are 
small. 
 
It is hard to do a more exhaustive test using the angular rate sensors without specialised 
software and equipment. For further calibration testing it is necessary to return the unit 
to OxTS. 
Note that the RT  is capable of correcting the error in the angular rate sensors very 
accurately. It is not necessary to have very small values for the angular rates when 
stationary since they will be estimated during the initialisation process and warm-up 
period. This estimation process allows the RT to go for long periods without requiring 
recalibration.