Integrated Micro-Inertial Sensors For GPS Denied Navigation Using Fast-Light Enhanced Ring Laser Gyroscopes and Accelerometers

ABSTRACT: For navigation of space platforms under GPS denied conditions, there is a need for micro-inertial sensors, with better accuracy and smaller volume and weight than the state of the art. We at Digital Optics Technologies (DOT) have been developing a superluminal ring laser gyroscope (SRLG) that can improve the accuracy of rotation sensing by nearly six orders of magnitude. Alternatively, for a given accuracy need, the SRLG can be very small. DOT has also developed the architecture for a superluminal ring laser accelerometer (SRLA), which can achieve a sensitivity of 10 pico-g/root-Hz. Under Phase II, we will employ a shared-cavity dual laser design, employing DPAL gain and Raman depletion, to demonstrate an SRLG with a rotation sensitivity of one micro degree per root hour, and an SRLA with a sensitivity of 10 pico-g per root Hz, two orders of magnitude better than the STAR accelerometer. We will also demonstrate the feasibility of realizing a three-axes miniature IMU, with three SRLGs and three SRLAs, with a diameter of 3.5 inch and a height of 3.35 inch. To this end, we will demonstrate a DPAL gain and Raman depletion based superluminal ring laser using a miniature dual-vapor-cell and a laser locking technique employing chip scale vapor cells. Finally, we will develop a complete, ready-for-production engineering design of a three-axes proto-type IMU of this volume that with minimized weight, power requirement and robustness suitable for space launch and operation on a space platform. Honeywell and Triad Technology will be subcontractors. 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 and light 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, as well as commercial aircraft inertial navigation systems