Intersense Introduction

The combination of the Intersense IS1200 and Airtrack® Precision Rotary Tracking bring a new level of on-stage camera tracking freedom and accuracy. However, to get the most out of the sensor, the tracking reference points on the stage must be set up correctly.

The IS1200 uses a fixed focal length camera with an 80 degree field-of-view to see and recognize binary coded digital optical fiducial targets, as shown here.

 

This represents fiducial #100. The binary coded digital pattern enables 32,768 different patterns to be recognized, enabling stages of arbitrary size to be successfully tracked.

Pose Solution

To solve for its position, the Intersense first captures a black and white frame through its wide angle lens, and attempts to recognize any fiducial marks that appear in the frame. The IS1200 needs a minimum of 4 visible markers to properly solve for its position.

The position algorithm will use the quadrilateral formed by the 4 recognized targets that are furthest from the center of the lens to solve for the 3D position of the camera. In this case, the 4 furthest targets would be 100, 250, 1000, and 850.

The further toward the edges that the recognized targets appear, and the more accurately their absolute 3D coordinates are known, the more accurate the solve.