GPS World, August 2013

EXPERT ADVICE The Chip Scale Combinatorial Atomic Navigator Andrei Shkel Defense Advanced Research Projects Agency DARPA F uture breakthroughs in microtechnology for positioning navigation and timing PNT will likely rely on yet tobe exploited physics new materials highly specialized fabrication technologies batch assembly techniques selective wafer level trimming and polishing a combination of passive and active calibration techniques strategically implemented right on chip and introduction of innovative test technologies Such microtechnology advances for PNT are sought because reliance on satellite based GPS for precision PNT information which is critical to the conduct of many types of military operations and the performance of a wide range of military weapon systems can mean dependence on a resource that may become inaccessible whether as a result of some type of component or overall system malfunction or as a consequence of deliberate enemy action The goal of the DARPA micro PNT portfolio of programs is to develop microtechnology for self contained chip scale inertial navigation and precision guidance that would effectively eliminate the dependence on GPS while enabling uncompromised navigation and guidance capabilities for advanced munitions and various military platforms under a wide range of operation conditions In 2012 under the project name C SCAN DARPA solicited innovative research proposals in the area of co integration of inertial sensors with dissimilar physics of operation in a single micro scale inertial measurement unit IMU This solicitation is an integral part of DARPAs microtechnology for positioning navigation and timing micro PNT portfolio of programs The overarching objective of the micro PNT portfolio is to develop technologies for self contained chipscale inertial navigation and precision guidance that could effectively eliminate the dependence on GPS or any other external signals and enable uncompromised navigation and A preferable military solution is to completely eliminate dependence on GPS or any other external signals during the mission guidance capabilities for advanced munitions mid and long range missiles and various military platforms under a wide range of operating conditions The micro PNT program includes a number of important specific efforts that focus on development of precision timing devices inertial sensors and microsystems C SCAN leverages the results of these efforts and expands the scope of the micro PNT program In this context the program sought to address challenges associated with the long term drift dynamic range and start up time of chip scale components for positioning targeting navigation and guidance tasks Specific interest lies in the development of a Chip Scale Combinatorial Atomic Navigator C SCAN that combines inertial sensors with dissimilar but complementary physics of operation into a single microsystem The main objectives of the C SCAN program are to explore miniaturization and co fabrication of atomic sensors with high performance solid state inertial sensors and develop combinatorial algorithms and architectures that seamlessly co integrate components with dissimilar physics in a single ensemble This column builds on material presented in a September 2011 GPS World article Microtechnology Comes of Age available at www gpsworld com microage That article also by Andrei Shkel described two then current efforts involving the development of clocks Chip Scale Atomic Clock CSAC and Integrated Micro Primary Atomic Clock Technology IMPACT and three efforts involving the development of inertial sensors and systems Navigation Grade Integrated Micro Gyroscopes NGIMG Micro Inertial Navigation Technology MINT and Information Tethered Micro Automated Rotary Stages IT MARS The 2011 article continued to explore four complementary new developments Microscale Rate Integrating Gyroscopes MRIG Chip Scale Timing and Inertial Measurement Unit TIMU Primary and Secondary Calibration on Active Layer PASCAL Platform for Acquisition Logging and Analysis of Devices for Inertial Navigation Timing PALADIN T This column goes yet further announcing the start of development of the Chip Scale Combinatorial Atomic Navigator C SCAN the subject of a 2012 Broad Agency Announcement and request for proposals GPS World August 2013 www gpsworld com 8