Integration of GPS with Inertial Navigation Systems

: An inertial navigation system (INS) exhibits relatively low noise from second to second, but tends to drift over time Typical aircraft inertial navigation errors grow at rates between 1 and 10 nmi/h (18 to 18 km/h) of operation In contrast, Global Positioning System (GPS) errors are relatively noisy from second to second, but exhibit no long-term drift Using both of these systems is superior to using either alone Integrating the information from each sensor results in a navigation system that operates like a drift-free INS There are further benefits to be gained depending on the level at which the information is combined This presentation will focus on integration architectures, including loosely coupled, tightly coupled, and deeply integrated configurations (Deep integration is trademarked by Draper Laboratory) The advantages and disadvantages of each level of integration will be listed Examples of current and future systems will be cited

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INS/GPS Integration Architectures

Precise Point Positioning Inertial Navigation Integration for Kinematic Airborne Applications

https://researchrepository.wvu.edu/cgi/viewcontent.cgi?article=7965&context=etd

Effects of Parent and Peer Behaviors on Adolescent Sexual Behavior: Are Positive and Negative Peer Behaviors Moderators?

/pdf/precise-point-positioning-inertial-navigation-integration-y2my42i1bd.pdf

: This report is presented in two parts. Part 1 presents the results of a feasibility study of a low-cost integrated GPS-inertial (strapdown) navigation system for Army attack helicopters. The conclusion is reached that a GPS-Doppler navigation system can more easily attain the cost and performance goals. It was also concluded that an integrated GPS-Doppler-inertial system might be very attractive if it could be used for providing attitude and heading reference data as well as navigation data. There would be a cost savings association with avoiding the need for the usual attitude and heading reference systems. Moreover, the integrated GPS-Doppler-inertial system would have excellent performance in the presence of aircraft dynamics and jamming. Part 2 presents the results of a study of advanced GPS signal processing techniques. Covered in the study are data aiding, comparison of phase-locked loops with Costas loops, variable predetection bandwidths in code-tracking loops, code loop dithering, aided tracking, variable tracking bandwidths, and effective gains of detectors in the presence of noise. The results are from computer simulation and theoretical analysis. (Author)

Feasibility Study of GPS-Inertial Navigation for Helicopters and Study of Advanced GPS Signal Processing Techniques. Volume III.

: The performance requirements for the GPS X-set impose difficult and conflicting design problems on the receiver. To accurately track the incoming signals in a high-dynamics environment, a wide-bandwidth tracking loop is required with a high-order tracking network. For best performance in the presence of noise, on the other hand, a narrow bandwidth tracking loop is desired. Techniques for utilizing an Inertial Measurement Unit (IMU), such as the Advanced Inertial Reference Sphere (AIRS), to aid the receiver tracking loops are studied. The IMU can provide accurate information on translational accelerations and orientation changes experienced by the receiver. By properly using the IMU data, the receiver bandwidth can be reduced without increasing the dynamics-induced tracking error. The end result is an improvement in performance in noisy or jamming situations.

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA057656&Location=U2&doc=GetTRDoc.pdf

William M. Stonestreet

Papers

Feasibility Study of GPS-Inertial Navigation for Helicopters and Study of Advanced GPS Signal Processing Techniques. Volume III.

Functional Requirements of the Interface Between the NAVSTAR GPS Receiver Model X and the Advanced Inertial Reference Sphere. Volume II.