TY - CONF T1 - Passive optical methods for helmet tracking in aircraft JO - SPIE Proceedings UR - https://doi.org/10.1117/12.543243 PY - 2004/04/12 AU - Vitarius PJ AU - Gregory DA AU - Morell D ED - Casasent DP ED - Chao T-H DO - DOI: 10.1117/12.543243 PB - SPIE VL - 5437 SP - 223 EP - 223 Y2 - 2026/02/04 ER -