Auto-Correcting Inertial Measurement Unit

DoD space surveillance and weapons systems require highly accurate inertial knowledge in absolute location and angular orientation. Current technologies providing these functions are not integrated into a single, light-weight, low-cost, power-efficient instrument. Applied Technology Associates (ATA) proposes to further develop its innovative and patented optical inertial reference unit technologies, denoted the MSTAR Inertial Reference Unit (MIRU) (Patents No 6,653,611 and 6,700,109 and Appl Ser No. 60/481,829) to design and demonstrate an autocorrecting inertial measurement unit (ACIMU). The MSTAR concept employs a combination of state-of-the-art inertial sensors and novel blending algorithms to achieve sub-microradian line-of-sight stabilization and optical pointing. The MSTAR advances and technologies are being incorporated into the Advanced Inertial Reference Unit (aIRU). Pre-mission, star tracker enabled calibration and low-drift gyros are used to give aIRU the capability for long term knowledge of angular orientation (20 microradians after 4 hours). ATA's proposed ACIMU instrument will combine aIRU technologies with embedded GPS functions and star-tracker measurements. We propose to incorporate novel, autonomous star-tracker technology that is being brought forward under NASA-sponsored R&D into the ACIMU. Performance of this star-tracker is projected to meet an accuracy goal of 1 microradian and an NEA goal of 500 nanoradians.