Motorola Automobile Accessories F5218 用户手册

Automatic Calibration takes place continuously & transparently during periods of good GPS 

reception while driving around.

• Accuracy improves over time of operation
• Fully compensates effects from aging (aging effects of gyroscope)
• Temperature compensation enables high accuracy at different temperatures

• Offset(Recognize straight routes)
• Scaling factor(Adjust sharpness of turns)
• Temperature compensation to gyroscope scaling factor and offset

• Scaling factor(Relationship between pulse rate and speed)

• With a new GPS receiver installed in a new vehicle, the accuracy is only moderately good 

until sufficient calibration data has been collected, e.g. during a first drive

• With the time, continuous calibration results in continuous improvement of dead 

reckoning accuracy

• Small discontinuities, like deviating wheel diameters from exchanging tires (summer vs. 

snow tires), will be balanced out by ongoing automatic calibration

• Applicable if the Sensor-based GPS receiver is transferred to a different vehicle or if a 

different gyroscope is connected.

• Calibration parameters must be reset. A UBX-message (UBX-CFG-EKF) is available to 

invoke the reset.

• For optimum navigation performance the new system needs some one-time learning time 

and distance for calibrating the various sensors inputs.

• Normally, a good level of calibration is achieved very quickly with a single short road trip 

where GPS reception is good.

- Odometer pulses are calibrated with driving a distance (scaling factor)