ECE 4164
Lecture Set 4:
Precise Satellite Position Calculation
Correction of Kepler Orbits
First consider important physical effects that
perturb GPS satellite orbits
Determine actual perturbations on the six
ephemerides; M0, a, e, i, , l
This entails
ECE 4164
Lecture Set 11:
GPS Communication Link Concepts:
Theory and Applications
GPS Communication Link
This discussion will provide a description of the GPS
communication link (particularly loss mechanisms).
It ultimately provides the answer to the qu
ECE 4164
Lecture Set 2:
Coordinate and Time Systems
Role of Coordinate Systems
Basic GPS satellite position calculation
GPS satellite
ephemeris data sent
from satellites
Determination of
satellite positions in
ECEF coordinates
Determination of
navigati
ECE 4164
Lecture Set 3:
Coarse Satellite Position Calculation
Basic GPS satellite position calculation
Space Segment
User Segment
Satellite ephemeris data sent from satellites
Coarse positioning requires six ephemerides:
1. : true anomaly
2. a: semi-maj
ECE 4164: QUIZ 1, October 5, 2016
NAME:_SIGNATURE:_
Instructions: Answer the following 8 questions by clearly circling the correct answer.
NOTE: For a spherical earth assume rE = 6371 km.
1. Assume a GPS receiver location in WGS-84 is given by
(latitude =
ECE 4164
Lecture Set 1:
Basic GPS Radio Navigation Concepts
GPS Milestones
1960s: TRANSIT, 6 satellites, used to determine locations of
aircraft and ships for the military. Problems: limited availability
and relatively low accuracy
1967: The Timation sate
ECE 4164
Lecture Set 6:
The Navigation Solution
Two Types of Navigation Solutions
1. Code Range (use Pseudorange equation)
-most common type used in commercial receivers
-uses Pseudoranges and Pseudorange equations
-use for on the fly calculations
2. Phas
ECE 4164
Lecture Set 10:
Differential GPS
Need for Differential GPS (DGPS)
Many applications require sub-meter ( under 10 cm) accuracy. DGPS
provides such accuracy and was initially developed to eliminate
Selective Availability (SA).
The concept is to u
ECE 4164
Lecture Set 5:
GPS Observables
Three GPS Observables
1. Pseudorange (meters)
2. Doppler Frequency (Hz)
3. Integrated Carrier Phase (Cycles)
These three observables are used along with satellite
locations for the position or velocity calculation.