Compact and Integrated IMU for GPS Denied Navigation Using Fast-Light Gyroscopes and Accelerometers

ABSTRACT:For GPS denied navigation, there is a need for developing inertial measurement units (IMU), employing gyroscopes and accelerometers, with better accuracy and/or smaller volume and weight than the state of the art.Under Phase I, we have established the feasibility of realizing a superluminal ring laser gyroscope (SRLG) and a superluminal ring laser accelerometer (SRLA), based on diode-pumped alkali lasers (DPALs), augmented by a fast-light Raman cells.The SRLG can improve the accuracy of rotation sensing by nearly five orders of magnitude.Alternatively, for a given accuracy need, the SRLG can be very small.The SRLA can be very compact, and achieve a sensitivity of 10 pico-g/Hz.The primary goal of the Phase II effort is to demonstrate a prototype IMU that would house three SRLGs and three SRLAs for 3-axis rotation and acceleration sensing, utilizing miniature vapor cells and frequency-stabilized lasers.The prototype will be tested and analyzed in order to identify any possible technical hurdles in meeting the size, weight, power and performance goals stated in the solicitation, as well as to address applicability to weapon systems and aircraft/spacecraft environments.Northwestern University will participate as a subcontractor.Dr. Selim Shahriar, inventor of the SRLG and the SRLA and the chief scientific adviser at DOT, will coordinate the overall effort.BENEFIT:Three SRLAs, combined with three SRLGs, can be used to realize a high accuracy IMU that is very compact andlight weight.Such an IMU could also be relatively inexpensive.An IMU of this type could have a significant impact on guidance, navigation and control systems for spacecraft, launch vehicles, missiles, kill vehicles, smart munitions, and other applications requiring precision inertial knowledge.Non-DoD applications include spacecraft guidance, navigation and control, commercial aviation, emergency response in urban canyons, mining and tunneling operations, and maritime operations.