orbital mechanics

EE-483 SPRING 2015SATELLITE COMMUNICATIONS

Lecture 2Orbital Aspects

Orbital Mechanics

2

Defining “Space”3

Is 100 miles (160 km) enough???4

Newton’s Laws of Motion5

Concept of Force6

Acceleration Inwards7

Acceleration Outwards8

Forces on a Satellite9

Balancing the Forces - 110

Example Circular Orbits11

Mean Earth radius is 6378.138 km and GEO radius from the center of the Earth is 42,164.17 km

Table 2.1 Orbital Velocity, Height, and Period of Four Satellite Systems

Orbit Limits12

Orbital Mechanics:Kepler’s Laws

13

Coordinate System 1 –Earth Main Planes

14

Coordinate System 2 –Orbital Plane Coordinate System

15

Developing Equations of the Orbit - 1

16

Developing Equations of the Orbit - 2

17

Kepler’s Three Laws18

Review of Ellipse Geometry19

Kepler’s First Law: Elliptical Orbits20

Orbit Characteristics21

Orbit Eccentricity22

Kepler’s Second Law: Equal Area Arcs

23

Kepler’s Third Law: Orbital Period24

Solar vs. Sidereal Day - 125

Solar vs. Sidereal Day - 226

Solar vs. Sidereal Day - 327

Solar vs. Sidereal Day - 428

Numerical Example 1: The GEO Orbit

29

Locating the Satellite in Orbit - 130

Locating the Satellite in Orbit - 231

Locating the Satellite in Orbit - 332

Orbit Description –1(Orbital Constants)

33

Orbit Description –2(Orbital Constants)

34

Orbit Description - 335

Locating Satellite with respect to Earth

36

Measuring Time37

Geocentric EquatorialCoordinates -1

38

Geocentric EquatorialCoordinates -2

39

Locating the Satellite -140

Defining Parameters -141

Defining Parameters -242

Locating the Satellite -243

Orbital Elements44

Numerical Example 2:45

Numerical Example 3:46