InterSense Inc. of Burlington, Mass., has won a Phase I Small Business Innovation Research contract from the US Army Research, Development and Engineering Command to develop and demonstrate a cockpit helmet tracker, employing its expertise in inertial-based motion tracking systems. The investigation will combine technology from the company's optical-inertial IS-1200 VisTracker with sensor fusion algorithms to fabricate a differential inertial sensing system. The prototype is expected to achieve submillimeter position and submilliradian orientation tracking accuracy suitable for use in rotary and fixed-wing aircraft. The small, lightweight system is intended to stabilize imagery captured by aircraft sensors and displayed in the cockpit.