IEEE/ION PLANS 2008 TUTORIALS

Tutorials will be offered in half-day sessions on Monday, May 5.

Click on course titles for detailed information and instructor biographies.

MONDAY MORNING, MAY 5, 8:30am-Noon

Fundamentals and Details of Satellite Navigation Using GPS
Instructor: Dr. Chris Bartone, P.E.

Network-Based RTK GPS and Precise Point Positioning
Instructor: Dr. Dorota A. Grejner-Brzezinska

Aviation Augmentations to GPS
Instructor: Dr. Chris Hegarty

MEMS Inertial Technology: A Short Course
Instructor: Ralph E. Hopkins

 

MONDAY AFTERNOON, MAY 5, 1:30pm-5:00pm

Precise Time & Frequency Applications
Instructor: Ron Beard

Low-Cost INS
Instructor: Dr. James L. Farrell

Fundamental Issues Affecting GPS/INS Integrations
Instructor: G. Jeffrey Geier

GPS Protection Toolbox: Picking the Right Technology for Interference Suppression
 Instructor: Dr. Ira M. Weiss & Allen W. Morrison

 

MONDAY, MAY 5, 8:30am-Noon

Fundamentals and Details of Satellite Navigation Using GPS
Dr. Chris Bartone, P.E.

Course Description

This course emphasizes the fundamentals of satellite navigation using Global Navigation Satellite Systems with emphasis on GPS. The course will begin with an introduction of the GPS Segments (space, control, and user) followed by an overview of other GNSS architectures (i.e. Galileo, Glonass, etc.). An overview of GPS receiver and antenna technologies will briefly be discussed. Various coordinate frames and datums used in the application of satellite navigation systems will be presented. Details of the GPS signal structure formats for current and future signals will be presented and discussed. Details on the calculation of the GPS space vehicle (SV) position using the broadcast Kepler parameters and user state (i.e. position and time) with associated performance parameters (i.e. dilution of precision terms) will be presented. Atmospheric and other error sources will be briefed. An introduction to differential GPS (DGPS) will be presented illustrating various ways to implement it. Various applications of GPS and DGPS as well as future trends in satellite navigation will be discussed at the conclusion of this course.

Level: Beginning to Intermediate

Course Outline

  • The GPS Segment (Overview)
  • The GPS and other Coordinate Frames
  • GPS Receiver and Antenna Technologies (overview)
  • The GPS Signal Structure
  • The GPS Navigation Message
  • Calculation of SV Positions Using Almanac and Ephemeris
  • Calculating User Position, Velocity, and Time
  • Dilution of Precision and Related Parameters
  • Details of Atmospheric Corrections for Satellite Navigation
  • Errors in Satellite Navigation Systems
  • DGPS and ways to implement it
  • Future trends in GNSS

Instructor Biography

Dr. Chris Bartone, P.E., is an associate professor at Ohio University. He received his Ph.D. in EE from Ohio University in 1998; he holds an MSEE from the Naval Postgraduate School (1987) and a BSEE from Penn State (1983). Chris has 25 years of experience working with communications, navigation, and surveillance (CNS) systems. Starting in 1983, Chris worked for the Naval Air Warfare Center-Aircraft Division performing research and development on CNS systems. At NAWC-AD, he was the program manger of the Air Combat Environment Test and Evaluation Facility, Communications, Navigation, and Identification Laboratory. At Ohio University, Dr. Bartone developed a number of graduate-level classes on GPS, radar, and wave propagation; his research concentrates on all aspects of navigation. He received the RTCA William E. Jackson Award in 1998 for his outstanding contributions to aviation. He is a member of the ION, IEEE, SAE, ILA, and the Association of Old Crows. He has served the ION Council as air representative, eastern region vice president, and is currently the chair of the ION outreach committee and editor, of the ION virtual navigation museum. He has helped organize many ION and IEEE conferences. Dr. Bartone is a licensed engineer and President of GNSS Solutions Ltd.

 

MONDAY, MAY 5, 8:30am-Noon

Network-Based RTK GPS and Precise Point Positioning
Dr. Dorota A. Grejner-Brzezinska

Course Description

The instantaneous long-range real-time kinematic (RTK) technique is the most challenging GPS data reduction method. As the base-rover (kinematic user) separation increases, many distance-dependent biases, such as atmospheric or orbital errors, may become significant even in differential mode, which complicates the ambiguity resolution process. This, in turn, may seriously corrupt the positioning and time transfer results, unless these effects are properly accounted for. The success of precise GPS positioning over long baselines depends on the ability to resolve the integer phase ambiguities when short observation time spans are required, which is especially relevant to RTK applications. Over the past few years, the use of a GPS reference station network approach has shown a great promise in extending receiver separation. The implementation of multiple reference stations in a permanent array offers several advantages over the standard single-baseline approach. It improves the accuracy and reliability of the mobile receiver positioning, and makes the results less sensitive to the length of the baselines, at the same time acting as a filter for lower quality measurements coming occasionally from some stations.

Moreover, the availability of high-accuracy GPS satellite orbits and clock corrections, provided by the International GPS Service (IGS), and atmospheric corrections, broadcast by local or regional networks, such as the Continuously Operating Reference Station (CORS) networks, makes Precise Point Positioning (PPP) competitive among other positioning methods. PPP can provide an interesting alternative to relative positioning applications, in particular in geodesy, surveying and navigation, enabling precise positioning with a single-receiver (i.e., low-cost), providing independence on any reference station (except for the broadcast correction source). The PPP applications are not limited by baseline length, and can be applied to different platforms, i.e., static and kinematic. Both PPP and network-based RTK enable the use of single-frequency receivers. It may be expected that centimeter-level accuracies will be achievable in RTK PPP mode in the future (current accuracy is at decimeter level), especially after GPS modernization is fully implemented (improved signal quality, additional frequency, etc.), offering a more attractive and economic alternative to traditional methods.

This workshop will provide an overview of the network-based RTK and PPP techniques, including algorithms and methods, as well as the descriptions and performance assessments of the available orbital, timing and atmospheric corrections and models, with a special emphasis on ionosphere modeling. Practical examples based on the Ohio CORS network data and a demonstration of the MPRGPS software package developed at The Ohio State University will be offered.

Level: Beginning to Intermediate. The participants are expected to have a basic understanding of GPS carrier phase-based positioning in differential mode. However, a brief review of basic models and error sources will be provided at the beginning of the workshop.

Course Outline

Why network-based RTK?

  • Limitations of the single-baseline RTK
  • Benefits with respect to the traditional single-baseline RTK
  • Instantaneous (single-epoch) versus on-the-fly (OTF) ambiguity resolution

Network-based atmospheric error modeling

  • Algorithmic Approach based on the OSU solution
  • Achievable accuracies

Rover solution based on the network-based corrections

  • Algorithmic approach based on the OSU solution
  • Ambiguity resolution: speed and reliability
  • Positioning accuracy

Applicability of external ionospheric model to the rover solution

Precise Point Positioning (PPP): concept and theoretical background

  • Algorithmic approach and error modeling
  • Accuracy and limitations of the external corrections supporting PPP
  • Example performance assessment
    • Static user
    • Kinematic user

Biography

Dr. Dorota Grejner-Brzezinska (PhD, OSU 1995) is an Assoc. Prof. in Geodetic Science, and leader of the Satellite Positioning and Inertial Navigation (SPIN) Laboratory at The Ohio State University. Her research interests cover precise kinematic positioning with GPS, GPS/INS integration, multi-sensor mobile mapping technology, personal navigation, precision orbit determination for GPS/LEO, and robust estimation techniques. She published over 120 peer reviewed journal and proceedings papers, numerous technical reports and three book chapters on GPS and navigation, and led over 20 research projects sponsored by DOD, NASA, NGS, NGA, NSF, Federal DOT, Ohio DOT, with a total budget of over nine million USD. She is the recipient of the 2005 ION Thurlow Award and the 2005 US Geospatial-Intelligence Foundation Research Achievement Award; she is a Fellow of the International Association of Geodesy (IAG).

 

MONDAY, MAY 5, 8:30am-Noon

Aviation Augmentations to GPS
Dr. Chris Hegarty

Course Description

The Global Positioning System (GPS) is relied upon extensively today for air navigation. To support the use of GPS for such applications, the international community has developed four classes of augmentation systems: aircraft-based (ABAS), satellite-based (SBAS), ground-based (GBAS), and ground-based regional (GRAS). This tutorial provides an introduction to these classes of aviation augmentations to GPS. After a discussion of operational requirements for air navigation and the deficiencies of stand-alone GPS in meeting these, the three classes of aviation augmentations are described. Examples of currently operating and planned systems within each class are presented (i.e. RAIM, FD, FDE, WAAS, LAAS, EGNOS, MSAS and GAGAN). Relevant domestic and international standards, and certification guidance materials are summarized.

Level: Intermediate. Attendees are assumed to have a basic understanding of the methods of position determination using GPS.

Course Outline

 Introduction

  • Air navigation operational requirements
  • Performance/deficiencies of stand-alone GPS
  • Overview of aviation augmentations (ABAS, SBAS, GBAS)

Aviation augmentations

  • Aircraft-based: RAIM, FD, FDE, inertial, baro-altimeter & clock
  • Satellite-based: Conceptual overview and functionality
  • Ground-based: Conceptual overview and functionality

Practical aspects

  • Standards: ICAO, RTCA, EUROCAE, Civil Aviation Authorities
  • ABAS, SBAS, GBAS examples

Biography

Dr. Chris Hegarty been involved with aviation applications of GPS at MITRE’s Center for Advanced Aviation System Development since 1992. He is the chair of RTCA’s Program Management Committee, co-chair of RTCA Special Committee 159, and associate editor of NAVIGATION: The Journal of the Institute of Navigation. He was a co-recipient of the 1998 ION Early Achievement Award and the recipient of the 2005 ION Johannes Kepler Award. He is currently serving as executive vice president of the ION.

 

MONDAY, MAY 5, 8:30am-Noon

MEMS Inertial Technology: A Short Course
Ralph E. Hopkins

Course Description

This course will present an overview of how the micro-electro-mechanical systems (MEMS) technology is revolutionizing the inertial guidance navigation and control (GN&C) industry. Suitable for those new to the MEMS and inertial disciplines, this course will also be of interest to more experienced practitioners as it will cover an overview of basic inertial sensing principles, detailed discussion of MEMS gyroscope and accelerometer designs, and MEMS fabrication and sensor packaging technologies. Current industry trends will be discussed along with examples of MEMS inertial technology in the commercial, military and space sectors, including advanced systems which integrate inertial MEMS with GPS. This course will be of interest to R&D, systems and manufacturing engineers, managers and executives, and will conclude with a discussion on the future direction of MEMS technology.

Level: Beginning to Intermediate

Course Outline

  • Overview of Inertial Sensing
  • Inertial MEMS Development
  • MEMS Accelerometers – Theory and Design
  • MEMS Accelerometers – Examples and Performance Data
  • MEMS Gyroscopes – Theory and Design
  • MEMS Gyroscopes – Examples and Performance Data
  • MEMS Fabrication Processes and Packaging
  • System Applications and Requirements
  • Developments in MEMS INS/GPS
  • Future Direction of MEMS Technology

Biography

Ralph Hopkins is a Principal Member of the Technical Staff and Group Leader in the Guidance Hardware Division at Draper Laboratory where he is responsible for the design and development of inertial instruments and sensors. Ralph has served as Technical Director of the Silicon Oscillating Accelerometer development program, a high performance silicon MEMS VBA targeted for strategic grade applications. Ralph has also led and contributed to the development of navigation and tactical grade MEMS gyroscopes and accelerometers, and high performance electro-mechanical inertial sensors such as floated instruments and Dynamically Tuned Gyros. He holds several patents, has authored several papers and is an invited speaker for short course tutorials on inertial instruments and inertial technology.

Ralph holds s a BS and ME in Mechanical Engineering from Rensselaer Polytechnic Institute, an ME in Engineering Mechanics from Columbia University, and an MS in Engineering Management from The Gordon Institute of Tufts University. He is a former member of the AIAA Guidance Navigation and Control technical committee.

 

MONDAY, MAY 5, 1:30pm-5:00pm

Precise Time & Frequency Applications
Ron Beard

Course Description

The tutorial on precise time and frequency (PT&F) applications will introduce the subject with an overview of the fundamentals of PT&F signals their generation and measurement. An introduction to time scales, those in use, and their origin will be described to provide an understanding of how traceability of PT&F is needed throughout its generation, dissemination and use. The distinction between global time scales and those generated and used within systems will be described to provide an understanding of their basic differences and strengths. This foundation in the fundamentals it will provide the basis for understanding the uses within military systems. The two major system application areas are telecommunications and navigation-positioning. Usage in these two areas differs as does their vocabulary, which is similar enough to be confusing to many new to the field or crossing between areas. The distinctions and commonalities will be discussed so that applications in both areas may be better understood. In system use the initial focus will be PT&F application to GPS, which has become the primary time dissemination system for the Department of Defense. How GPS supports time dissemination and time transfer interfaces with many and varied systems will be covered in some depth. Examples of different system applications will be discussed. The session will conclude with a projection of future directions of PT&F and its application.

Level: Beginning to Intermediate

Course Overview

  • Fundamentals - A Review of Definitions and Standards and their associated Performance Metrics and Measurement Techniques.
  • Overview of Oscillators and Clocks - To include an overview of the types of clocks and oscillators. A brief introduction to their fundamental of operation with some example uses.
  • Timekeeping and Time Scales – Beginning with an introduction into the fundamentals of timekeeping, the International Time Scales, their formation and contributors will be discussed. Some of the more important aspects of systems timekeeping will be discussed.
  • Time Transfer & Time Dissemination – The basic techniques and systems involved will be discussed. Space based systems will be the focus since they are the major contributors today.
  • Precise Time and Frequency in System Uses and an overview of applications including telecommunications uses.

Biography

Mr. Beard has a B.S. in physics (1967), McNeese State University in Louisiana and graduate work at GWU, Washington, D.C. He was Project Officer for Satellite Navigation, Astronautics Division, Naval Air Systems Command HQ (1968 – 1971). In 1971, he began with the NRL TIMATION Project. From 1973-1979, he was the Project Scientist in the NRL GPS Program Office that developed Navigation Technology Satellites One and Two and operated the first atomic clocks in space. From 1979-1983, he was the Deputy Project Manager for the Naval Space Surveillance System Modernization Program. In 1984, he became the Head of the Space Applications Branch and NRL GPS Clock Development Program. Since that time he has been involved in numerous studies and panels relating to PT&F development. He is currently Chairman of ITU-R Working Party 7A responsible for Precise Time and Frequency Signal Services Worldwide and a member of Sigma Xi, ION, AGU, and AIAA.

 

MONDAY, MAY 5, 1:30pm-5:00pm

Low-Cost INS
Dr. James L. Farrell

Course Description

The title of this course is taken literally, emphasizing the “S” in “INS” with a SYSTEM focus. It complements related courses (Fundamental Integration, MEMS Inertial Technology) by defining all tools (digitization, synchronization, sampling, algorithms) that convert raw MEMS data to familiar nav system outputs (attitude, velocity, position). The processes can differ in some important ways from corresponding steps common to current INS approaches. That is fortunate, since the differences considerably enhance comprehension; while current methods are not universally understood, procedures given herein will be transparently clear to all. Van and flight results algorithms will be presented with test data from Ohio University. Inertial nav background is not essential, but attendees should understand small matrices (i.e. 3x3 direction cosine transformations) prior to taking the course.

Level: Intermediate

Course Outline

  • Short-term nature of MEMS inertial instrument processing
  • Short-term implications allow more straightforward algorithms
  • Complete straightforward steps to get INS attitude from raw MEMS gyro outputs
  • From attitude plus raw MEMS accelerometer outputs to INS velocity
  • Preprocessing: A/D, sampling, sync, coning and sculling (simplified yet more general derivation of sculling)
  • Additional error sources needing more attention in strapdown mechanizations (oscillatory instrument error rectified by attitude)
  • Oscillation (cross-axis errors from imperfect mounting take effect immediately)
  • Raw data usage: the key to huge cost savings plus unprecedented flexibility
  • Verification: Successful results using algorithms with GPS-updated IMUs
  • What these algorithms offer: state-of-the-art accuracy from low-cost equipment

Biography

Dr. James L. Farrell (MS, UCLA, 1961; Ph.D., U of MD, 1967) is a member of ION, senior member of IEEE, former local board member of AIAA, registered professional engineer in Maryland, and a member of various scholastic honorary fraternities. Technical experience includes temporary teaching at Marquette and UCLA, two years each at Minneapolis Honeywell and Bendix-Pacific, and 31 years at Westinghouse in design, simulation, and validation/test for modern estimation algorithms in navigation and tracking applications and also digital communications system design (synchronization, carrier tracking, decode). He is author of the books, GNSS Aided Navigation and Tracking (2007) and Integrated Aircraft Navigation (Academic Press, 1976), former columnist at Washington Technology, and has written over 80 journal or conference manuscripts. Teaching activity over the past two decades include Navtech Seminars and self-sponsored courses at ION-GPS and at IEEE PLANS. He co-chaired RTCA GPS Integrity FDI Group. At VIGIL Inc. his teaching has continued (campus, Industry and conferences) while consulting for industry, DoD, and university research.

 

MONDAY, MAY 5, 1:30pm-5:00pm

Fundamental Issues Affecting GPS/INS Integrations
G. Jeffrey Geier

Course Description

The integration of GPS with an Inertial Navigation System improves the quality and integrity of each navigation system: use of GPS permits calibration of inertial instrument biases, and the INS can be used to improve the tracking and reacquisition performance of the GPS receiver and its jamming tolerance.

This course will first review the key requirements drivers for the integration, and contrast the different integration architectures, ranging from loosely integrated decentralized approaches to Ultra-Tightly Coupled (UTC) centralized designs.

Following a brief review of Kalman filtering basics, candidate filter designs will be examined in light of the integration requirements. Kalman filter modeling issues will be raised as design challenges.

GPS receiver assistance, in the form of both acquisition and tracking aid, will also be explained at a conceptual level. Finally, applications in the tactical missile and automotive environments will be used to provide examples of the practical application of the discussions.

Level: Beginning to Intermediate. Although the course material will be presented at a conceptual level, student familiarity with GPS, inertial navigation, and Kalman filtering is assumed.

Course Outline

Introduction to GPS/INS Integration

  • Motivation: the integration synergy
  • Review of Kalman filter basics
  • Categorization of approaches
  • Centralized, decentralized filter approaches

Kalman Filter Design Issues

  • INS error modeling
  • GPS error modeling

GPS Receiver Assistance

  • Acquisition
  • Tracking

Examples

  • RAPToR (Tactical missile environment)
  • L-3 (Guided Munitions)
  • Car navigation in the urban environment

Biography

Jeff Geier is an engineering fellow at Raytheon Missile Systems, and has 40 years of experience with integrated navigation systems, GPS navigation and signal processing, and integrity monitoring. His past experience in GPS/INS integration includes both military (CSDL, TASC, Intermetrics, Aerospace) and commercial (Trimble, Motorola) applications. At Motorola, he led efforts to integrate their GPS receiver technology with dead-reckoning sensors for automotive applications, and was appointed to Motorola’s Science Advisory Board. Mr. Geier is a member of ION and IEEE and holds 30 patents. He received his BS and MS degrees in Aeronautics and Astronautics from MIT.

 

MONDAY, MAY 5, 1:30pm-5:00pm

GPS Protection Toolbox: Picking the Right Technology for Interference Suppression
Dr. Ira M. Weiss & Allen W. Morrison

Course Description

This tutorial reviews the various technologies that are both currently implemented and proposed to mitigate the effects of jamming and unintentional interference on GPS signal reception and navigation. The performance benefits and limitations of each technology will be presented. The building blocks of anti-jam techniques are discussed, including receiver spread spectrum processing, adaptive antenna arrays and associated control electronics, miniature arrays, adaptive digital filters, and signal processing algorithms, including space-time and space frequency adaptive processing. Techniques and metrics used to characterize each major component of interference suppression systems and overall GPS system anti-jam performance are described. The course is useful for engineers and managers and other technical personnel who want to gain an understanding of the increasingly important subject of GPS interference suppression principles, techniques, and trade-offs. People taking this course are assumed to have an understanding of GPS operation and measurements, signal theory and engineering analysis.

Level: Beginning

Course Outline  

  • GPS interference and jamming effects in the presence of GPS legacy and modernized signals
  • Antenna array basics
  • Adaptive antenna algorithms and processing issues
  • Antenna electronics design considerations
  • Signal processing interference suppression filters
  • Space-time/space-frequency adaptive processing benefits and implementation trade-offs, including multipath performance issues
  • Antenna array and electronics characterization testing, including test metrics and configurations for system level interference suppression characterization

Instructor Biography

Dr. Ira M. Weiss is a senior engineering specialist for the Aerospace Corp. in the Communication Systems Engineering subdivision where he has worked in GPS related areas for over 27 years.

Allen W. Morrison is an assistant vice president for technology for SAIC where he has worked extensively in the application of digital signal processing techniques for interference mitigation in GPS-based navigation systems.