Course 331: Weak Signal Tracking and High-Sensitivity GPS for Indoors

Instructors	Dr. Gérard Lachapelle, University of Calgary Dr. Mark Petovello, University of Calgary
About This Course	The ever-increasing demand for position availability has forced receiver manufacturers to adapt traditional signal tracking algorithms to operate in weak signal or indoor environments. This course covers the basic concepts of GPS receiver operation before explaining how these methods are improved upon for use in weak signal environments. Where possible, concepts are described/presented from different perspectives in an attempt to improve comprehension and to accommodate different learning styles. In particular, heuristic, time domain and frequency domain explanations are given where appropriate. Numerical examples are also included to further illustrate certain ideas and concepts. Numerous real-world case studies are also presented to emphasize and clarify various topics. This course can be given onsite and is typically taught over three days. However, course duration and content can be adjusted somewhat to address client requirements.
Prerequisites	An understanding of GPS principles, such as presented in Course 122 is beneficial, but not required.
Who Should Attend?	This course is for engineers and analysts interested in acquiring knowledge of how weak signal tracking is implemented and/or achieved. The course provides both theoretical background information and practical examples to better illustrate important aspects, thereby providing a comprehensive approach to understanding and analyzing these systems.
Course Schedule	DAY 1 **Dr. Gérard Lachapelle and Dr. Mark Petovello**
	8:30 - GPS Overview *Review of Fundamental GPS Theory* Origins of GPS; Navigation Fundamentals and Requirements; Space, Control and User Segments; System Error and Accuracies; Geometry Considerations *GPS Signal Structure* RF propagation; Fresnel zones; Reflection; Refraction; Attenuation; Modulation; Pseudo-Random Noise (PRN) Codes and Their Properties; Frequency Domain Overview; Navigation Information 9:45 - *Observables* Pseudorange; Doppler; Carrier Phase; Carrier Phase Ambiguity Satellite Ranging Concept Measurement Overview; Pseudorange Measurements Using Correlation; Dilution Of Precision (DOP) and User Equivalent Range Error (UERE); Performance Measures 11:00 - Link Budget Radiated Power; Free Space Loss; Received Power; System Specifications Reference System Definition of WGS-84; Datum Transformations; Horizontal and Vertical Datums 12:00 - Lunch on your own 1:30 - GPS Receiver Operation #1 Overview Block Diagram; GPS Receiver Performance Issues; Classes of GPS Receivers RF Front End Antenna; Local Oscillator (Characterizing Time Scales, FTS, Allan Variance); Preamplifier; Friss’ Formula; C/N_o and its Relevance; Relationship Between C/N_o and SNR; Down Conversion and Frequency Mixers; Sampling 2:45 - Signal Processing Overview Overall Objectives; Signal Acquisition; Signal Tracking; Navigation Message Demodulation; Measurement Generation; Navigation Solution 4:00 - Signal Tracking & Measurement Generation Objectives and Limitations; Doppler Removal; Code Correlation; Coherent Accumulation; Tracking Loops (DLL, FLL, PLL); Measurement Generation 5:00 - Day One Ends
	DAY 2 Dr. Lachapelle and Dr. Petovello
	8:30 - GPS Receiver Operation #2 Signal Acquisition Objectives and Limitations; Time and Frequency Search Space; Signal Detection and Acquisition Thresholds; Possible Implementations; Factors Affecting Acquisition; Signal Reacquisition Navigation Message Demodulation Bit Synchronization; Frame Synchronization; Parity Decoding; Obtaining GPS Time Navigation Solution 9:45 - GPS In Weak Signal Environments (High Sensitivity GPS) Motivation & Objectives E911/112 Mandates; Weak Signals; Typical Signal Attenuations; Overview of How to Handle Weak Signals Extended Coherent Accumulation Navigation Data; Navigation Bit Prediction; Relevance of Frequency Errors Non-Coherent Accumulation Definition; Squaring Loss; Relevant Factors Affecting Squaring Loss; Weak Signal Exercises & Examples Signal Acquisition in Weak Signal Environs. Frequency Bin Size Requirements; Search Space Size; Massive Parallel Correlation Review of Current Technologies Assisted GPS & Aiding Information Self Aiding; External Aiding Options; Overview of Aiding Standards 12:00 - Lunch on your own 1:30 - Differential GPS Overview Objectives; Motivation Implementation Between Satellite Single Differencing; Between Receiver Single Differencing; Double Differencing 3:15 - GPS Errors Satellite Errors Orbits; clocks Atmospheric Errors Ionosphere; Troposphere Receiver and Antenna Errors Noise; Multipath; Clock; Interference 5:00 - Day Two ends
	DAY 3 Dr. Lachapelle and Dr. Petovello
	8:30 - High Sensitivity GPS Receiver Implementation Issues Estimation and Reliability Review of Estimation Concept; Measurement Model; Least Squares; Kalman Filtering; System Model; Estimated Accuracy; Residual Testing; Statistical Reliability; Multi-Dimensional Accuracy Measures Possible Problems Overview; Increased Measurement Uncertainty; Poorer Reliability; Multipath; Echo-Only Signals; Cross-Correlation; Near-Far Problem Signal Modeling E-911 Mandate; Motivation; Objectives; Sample Results 11:00 - High Sensitivity GPS Receiver Case Studies #1 Performance Assessment In Urban Canyon Performance Assessment Under Forest Canopy 12:00 - Lunch on your own 1:30 - High Sensitivity GPS Receiver Case Studies #2 Performance Assessment Inside Various Buildings 2:45 - Hardware Simulator for HSGPS Description Motivation Testing Capabilities Tracking Threshold; GPS Fading Channel Model; Acquisition Threshold; Re-acquisition Threshold; Dynamics Testing 4:00 - Augmentation Options Overview Software Options; Sensor Options Sample Results Inertial Measurement Unit (IMU); Gyroscopes; Barometer; Pedestrian Navigation; Accelerometers; Processing Options 5:00 - Course ends
Materials You Will Keep	• A notebook containing all materials presented in the course. • A CD-ROM containing a variety of GPS references and useful, practical, supplementary materials to help you in your ongoing, applications-related activities.
Continuing Education Units	1.8 (18 hours) Return to top of page