1.1 Physical Fundamentals This attenuation is usually expressed in decibels (dB). By definition, an attenuation of n dB means signal propagation from the that the original field strength is decreased by ite to the user by means of factor of 10-0In electromagnetic waves. Such waves Physical quantities

Perigee and Apogee: The point of closest approach of the satellite with respect to the earth's center of mass is called perigee and the most distant position is the apogee. Nodes: The intersection between the equatorial and the nit sphere is termed the nodes, where the ascending node defines the northward

Basics of the GPs Technique: Observation Equations Geoffrey blewitt Department of Geomatics, University of Newcastle Newcastle upon Tyne NEl 7RU, United Kingdom

Today's Lecture Examine specifics of GPS signals Multiple modulations on same carrier signal Structure of signals GPS receiver operation and satellite acquisition

Outline Review u Examined basics of GPS signal structure and how gnal is tracked a Looked at methods used to acquire satellites and start g Today we look at

3. Reference Systems Book: p 25-38 Dr Guoqing Zhou 1.1 Overview 1.2 A Group of Basic Ce GPS Basic Positioning Principle

1. Basic Knowledge of GPS In 1973, DOd organized a Joint P Office (JPO) located at the U.S. Air Force Systems Command's Space The s Second Lecture Division, Los Angeles Air Force Base(AFB)to what?

GPS Basic Positioning Principle Two reference systems: Time and Coordinate Syst

1. Errors related to GPs Satellites 2. Errors related to GPS signal propagation in atmosphere 3. Error related to gPs receivers Gv Principles of the Global Positioning System

Fundamental knowledg Quick Overview Kelperian 3 Laws First Law: ellipse, Sun is a focus Second law: the same area in same time Earth