System and Method for Evaluating a Calibration of a Magnetometer on a Mobile Device

1 . A method of evaluating a calibration of a magnetometer on a mobile device, the method comprising:

obtaining a parameter associated with the calibration;

determining a component of the parameter along an axis of the magnetometer; and

determining a calibration quality indicator using the component.

2 . The method of claim 1 , wherein obtaining the parameter associated with the calibration comprises:

determining a cluster of a plurality of points used in the calibration;

determining a property of the cluster; and

using the property as the parameter.

3 . The method of claim 2 , wherein the property is an indicator of a variation in the plurality of points.

4 . The method of claim 3 , wherein the property corresponds to a size of the cluster.

5 . The method of claim 1 , wherein the parameter corresponds to a calibration parameter generated from the calibration.

6 . The method of claim 1 , wherein determining a calibration quality indicator comprises determining a rate of change of the component.

7 . The method of claim 5 , wherein the calibration parameter estimates a constant bias error of the magnetometer.

8 . A computer readable storage medium for evaluating a calibration of a magnetometer on a mobile device, the computer readable storage medium comprising computer executable instructions for:

obtaining a parameter associated with the calibration;

determining a component of the parameter along an axis of the magnetometer; and

determining a calibration quality indicator using the component.

9 . The computer readable storage medium of claim 8 , wherein obtaining the parameter associated with the calibration comprises:

determining a cluster of a plurality of points used in the calibration;

determining a property of the cluster; and

using the property as the parameter.

10 . The computer readable storage medium of claim 9 , wherein the property is an indicator of a variation in the plurality of points.

11 . The computer readable storage medium of claim 10 , wherein the property corresponds to a size of the cluster.

12 . The computer readable storage medium of claim 8 , wherein the parameter corresponds to a calibration parameter generated from the calibration.

13 . The computer readable storage medium of claim 8 , wherein determining a calibration quality indicator comprises determining a rate of change of the component.

14 . The computer readable storage medium of claim 12 , wherein the calibration parameter estimates a constant bias error of the magnetometer.

15 . A mobile device comprising a processor coupled to a memory and a magnetometer, the memory comprising computer executable instructions for:

obtaining a parameter associated with the calibration;

determining a component of the parameter along an axis of the magnetometer; and

determining a calibration quality indicator using the component.

16 . The mobile device of claim 15 , wherein obtaining the parameter associated with the calibration comprises:

determining a cluster of a plurality of points used in the calibration;

determining a property of the cluster; and

using the property as the parameter.

17 . The mobile device of claim 16 , wherein the property is an indicator of a variation in the plurality of points.

18 . The mobile device of claim 17 , wherein the property corresponds to a size of the cluster.

19 . The mobile device of claim 15 , wherein the parameter corresponds to a calibration parameter generated from the calibration.

20 . The mobile device of claim 15 , wherein determining a calibration quality indicator comprises determining a rate of change of the component.