Calibration results, 2 calibration results – PNI SeaTRAX User Manual

Page 33

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PNI Sensor Corporation

DOC#1018154 r02

SeaTRAX User Manual

Page 28

6.4.2

Calibration Results

Once a calibration is complete, the “Calibration Results” window will indicate the quality

of the calibration. This may take a minute or more to populate. The primary purpose of

these scores is to confirm the calibration was successful, as indicated by a low Mag

and/or Accel CalScore. The other scores provide information that may assist in

improving the CalScore, should it be unacceptably high. If either CalScore is too high,

click the <Start> button to begin a new calibration. If the calibration is acceptable, click

the <Save> button to save the calibration to the module’s flash. If the <Save> button is

not selected then the module will need to be recalibrated after a power cycle.

Note:

If a calibration is aborted, all the score’s will read “179.80”, and the calibration coefficients

will not be changed. (Clicking the <Save> button will not change the calibration coefficients.)

Mag CalScore

Represents the over-riding indicator of the quality of the magnetometer calibration.

Acceptable scores will be <1 for Full-Range Calibration, <2 for other methods. Note

it is possible to get acceptable scores for Dist Error and Tilt Error and still have a high

Mag CalScore value. The most likely reason for this is the SeaTRAX is close to a

source of local magnetic distortion that is not fixed with respect to the module.

Dist Error

Indicates the quality of the sample point distribution, primarily looking for an even

yaw distribution. Significant clumping or a lack of sample points in a particular

section can result in a poor score. The score should be <1 and close to 0.

Tilt Error

Indicates the contribution to the Mag CalScore caused by tilt or lack thereof, and

takes into account the calibration method. The score should be <1 and close to 0.

Tilt Range

This reports the larger of either half the full pitch range or half the full roll range of

sample points. For example, if the module is pitched +10° to -20º, and rolled +25º to

-15º, the Tilt Range value would be 20º (as derived from [+25º - {-15º}]/2). For Full-

Range Calibration and Hard-Iron-Only Calibration, this should be ≥45°. For 2D

Calibration, this ideally should be ≈2°. For Limited-Tilt Calibration the value should
be as large a possible given the user’s constraints.

Accel CalScore

Represents the over-riding indicator of the quality of the accelerometer calibration.

Acceptable scores will be <1.

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