Product Search

Call Us 800-628-0885 or 1-703-256-8900
Item Added to Cart

Course 336 Details


Course 336: GPS Fundamentals, Enhancements and Intro to Differential GPS  (1.8 CEUs) Public and On-Site (Also known as Course 336: GNSS Operations for Engineers, for course in Noordwijk) 
Instructor(s): Dr. Christopher Hegarty, MITRE 



This is a 3-day course that presents an overview of how the GPS systems works, its historical evolution, its many applications, and its policy and operational considerations. It provides the fundamentals of GNSS principles and technologies including clocks and timing, orbits and constellations, and satellites and control segment functions as well as an introduction to differential GPS. It  gives you a comprehensive introduction to GPS technology and an introduction to differential GPS. (Note: This course is offered every two years at ESTEC/ESA in Noordwijk. This course may also be selected as an on-site course.)


  • To give a comprehensive introduction to GPS and DGPS technology, system concepts, design, operation, implementation and applications.
  • To provide detailed information on the GPS signal, its processing by the receiver, and the techniques by which GPS obtains position, velocity and time.
  • To provide and introduction to differential GPS


Some familiarity with engineering terms is helpful but not essential.

Who Should Attend?

  • Engineers and technical professionals seeking conceptual and detailed explanations of GPS technology, operation, capabilities, applications, and development trends
  • Professionals in navigation, positioning, and related fields who are concerned with the capabilities, operation and principles of GPS, DGPS, and related GNSS systems.
  • System analysts and specialists concerned with position data and its use.
  • Managers concerned with GPS, GNSS activities, or the positioning field.

Materials You Will Keep

  • A color electronic copy of all course notes will be provided on a USB Drive or CD-ROM. Bringing a laptop to this class is highly recommended for taking notes using the Adobe Acrobat® sticky notes feature; power access will be provided. 
  • A black and white hard copy of the course notes will also be provided. 

Course Fee Entitles You to the Following Books

Introduction to GPS: The Global Positioning System, 2nd ed., Ahmed El-Rabbany, Artech House, 2006., OR Global Positioning System: Signals, Measurement and Performance, P. Misra and P. Enge, 2nd ed., 2011. (Note: This arrangement does not apply to on-site contracts. Any books for on-site group contracts are negotiated on a case by case basis.)

Monday Morning

Fundamentals of GPS Operation. Overview of how the system works. U.S. policy and current status.
GPS System Description
● System segments
● Basic principles of operation
Policy and Operational Considerations
● History, augmentations
● Modernization 
● Glonass
● Galileo
● Compass
GPS Applications
● Land
● Marine
● Aviation
● Science
● Personal navigation
● Accuracy measures

Monday Afternoon

GNSS Signal Structure
● Signal requirements
● Pseudorandom Noise Codes (PRN)
● Auto and cross-correlation
● Modulation and spread spectrum
● Navigation data
● Signal power levels
Navigation Solutions & Error Sources 
● Pseudorange measurements
● Least squares
Receivers: Basic Elements and Functionality
● Overview
● Front end
● Signal processing
● Acquisition
● Tracking

Tuesday Morning

GPS Principles and Technologies
Clocks and Timing
● Role of timing in GPS
● Timescales: solar time, atomic time, UTC, GPS time
● Clock stability, Allan deviation
● GPS satallite clock characteristics and broadcast corrections
● Receiver clock characteristics
● Relative effects on clocks
Orbits and Constellation
● Coordinate frames and geodesy
● Two-body orbits
● Orbit perturbations
● GPS satellite orbit representations
● GPS constellation
Satellites and Control Segment
● Block I, II, III satellites
● Control segment functions and upgrades

Tuesday Afternoon

Error Models
● Signal in space performance due to ephemeris and satellite clocks
● Ionospheric errors: dual frequency corrections, broadcast model
● Tropospheric errors: cause, mitigation using antennas, siting, signal processing
● Multipath effects:cause, mitigation using antennas, siting, signal processing
● Tracking errors
● Error budget
Augmentations, Regional, and Global Navigation Satellite Systems (GNSS)
● Ground-based augmentations: LAAS, DGPS
● Space-based augmentations: WAAS, EGNOS, GAGAN
● Regional satellite augmentations: QZSS, IRNSS
● Galileo: European GNSS
● Compass: Chinese GNSS
Precise Positioning
● Precise positioning concepts 
● Carrier phase models: single, double, tiple differences
● Ambiguity resolution
● Reference stations: local and global networks
● Precise orbits and clocks
● RINEX data format
● Software: overview of packages and online tools for precise positioning

Wednesday Morning

Differential GPS Overview
● Local-area, regional-area, wide-area architectures
● Code vs. carrier-phase based systems
● Pseudolites
● Performance overview
Differential Error Sources
● Satellite ephemeris errors
● Satellite clock errors
● Selective availability
● Ionospheric, tropospheric delay
● Multipath
● Receiver internal noise, biases
Observable Modeling
● Code pseudorange and carrier phase outputs
● Code-minus-carrier observables
● Carrier-smoothed code operation
● Double difference operation
● System error budgets

Wednesday Afternoon

DGPS Design Considerations
● Range vs. navigation domain corrections
● Data links
● Pseudolites
● Reducing major error components
● Ambiguity resolution
DGPS Case Studies I
● RTCM SC104 message format 
● USCG maritime DGPS and National DGPS (NDGPS)
● Commercial satellite-based systems
DGPS Case Studies II
● Wide Area Augmentation System (WAAS)
● Local Area Augmentation System (LAAS)
● RINEX format
● CORS&IGS network for precise positioning (survey)
● Precise time transfer
--> NavtechGPS, Suite 230, 5501 Backlick Road, Springfield, VA 22151-3940 USA