The United States Air Force (USAF) uses and evaluates a variety of helmet-mounted trackers for incorporation into their
high performance aircraft. The primary head tracker technologies commercially available are magnetic trackers, inertial
trackers, and optical trackers. Each head tracker has a unique method of determining the pilot's head position within the
cockpit of the aircraft. Magnetic trackers generally have a small head mounted size and minimal head weight. Because
they sense a generated magnetic field, their accuracy can be affected by other magnetic fields or ferrous components
within the cockpit. Inertial trackers cover the entire head motion box but require constant motion in order to
accommodate drifting of the inertial sensors or a secondary system that updates the inertial system, often referred to as a
hybrid system. Although optical head trackers (OHT) are immune to magnetic fields some of their limitations may be
daylight/night vision goggle (NVG) compatibility issues and, depending on system configuration, may require numerous
emitters and/or receivers to cover a large head motion box and provide a wide field of regard. The Dynamic Tracker
Test Fixture (DTTF) was designed by the Helmet Mounted Sensory Technology (HMST) laboratory to accurately
measure azimuth rotation in both static and dynamic conditions for the purpose of determining the accuracy of a variety
of head trackers. Before the DTTF could be used as an evaluation tool, it required characterization to determine the
amount and location of any induced elevation or roll as the table rotated in azimuth. Optimally, the characterization
method would not affect the DTTF's movement so a non-contact method was devised. This paper describes the
characterization process and its results.
In military aviation, head tracker technologies have become increasingly important to track the pilot's head position and
orientation, allowing the user to quickly interact with the operational environment. This technology allows the pilot to
quickly acquire items of interest and see Fighter Data Link type information. Acquiring the target on a helmet-mounted
tracker/display which can automatically slew a weapon's seeker is far more efficient than having to point at the target
with the nose of the aircraft as previously required for the heads-up display (HUD) type of target acquisition. The
United States Air Force (USAF) has used and evaluated a variety of helmet-mounted trackers for incorporation into their
high performance aircrafts. The Dynamic Tracker Test Fixture (DTTF) was designed by the Helmet-Mounted Sensory
Technology (HMST) laboratory to accurately measure rotation in one plane both static and dynamic conditions for the
purpose of evaluating the accuracy of head trackers, including magnetic, inertial, and optical trackers. This paper
describes the design, construction, capabilities, limitations, and performance of the DTTF.
The Dynamic Tracker Test Apparatus (DTTA) was designed by the Helmet Mounted Sensory Technology (HMST)
laboratory to accurately measure azimuth rotation in both static and dynamic conditions. The DTTA was characterized
for static position data at various increments through a 360° sweep and for speeds up to 1000°/sec or 17.45 rad/sec. This
paper describes the design, construction, capabilities, limitations, characterization and performance of the DTTA.
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