Airtrack Smoothing
The IS1200 provides a good global rotation reference, but has a very visible rotational noise of about 0.1 degree. The Airtrack is designed to remove this, and provide a usable track.
Airtrack Drift Compensation
As the Airtrack is an inertial (gyroscopic) system, it has a certain amount of drift. The Airtrack Drift panel provides control for this. Leaving the Auto Sample box checked causes Previzion to continuously sample and correct for the rate of drift.
When Previzion is started up, the system waits 20 seconds for the IS1200 to stabilize, then automatically aligns the coordinate systems of the two sensors. If you wish to manually align the coordinate system, click Reset Rotation.
If you wish to manually sample the drift, you can uncheck Auto Sample and click Sample Now, but this is not recommended.
Sensor selection
To see the raw data from the Intersense, deselect the Enable button next to the Airtrack label and green light. The Airtrack will still be used for synchronization, but will not be used for smoothing the Intersense data.
Frame Delay
The frame delay sets the delay of the tracking data to synchronize with the video. Digitizing the video frames always takes longer than bringing in the tracking data, so the delay lets you adjust this to make the images synchronize with the tracking motion.
Setting the delay is done by panning the camera back and forth somewhat sharply, and adjusting the frame delay back and forth by 1/2 frame at a time until the background stays locked.
Note: for accurate delay synchronization, the Airtrack must be selected for Rotation Smoothing, or an encoded head used for measuring Rotation.