1. Energy Fundamentals
Part Two

2. Overview Means of detecting the target
Sensing energy, emitted or reflected
Energy forms propagate as traveling waves categorized by frequency and wavelength

3. RADAR
What does RADAR stand for?
RAdio Detection And Ranging

4. Characteristics of Waves
Frequency (Hz)
Period
Wavelength
Velocity
Amplitude

5. Maxwell’s Theory What is Maxwell’s Theory?
Time varying electric field will produce a time varying magnetic field, and vice versa.

6. Formation of Electric and Magnetic Fields around an Antenna
E-line
Mag field e- e- e-
1. Show Slide and show electrical and magnetic fields.
2. Point out that:
- The magnetic field lines are at 90 degrees to the electrical fields lines.
- The field strengths are greater at the center of the antenna and less at
the ends.
3. Another good picture is fig. 2-9 on p.29 of text.
Electric field | Magnetic Field | Direction of Propagation.

7. Polarization What is polarization? Direction of Propagation? 3 Types?
Antenna direction for horizontal polarization?

8. Three Propagation Paths
Reflection
Refraction
Diffraction
Snell’s Law???
n1*Sin θ1=n2*Sin θ2

9. Three propagation types
Ground Waves
Sky Waves
Space Waves
Which is the highest frequency? Why does it have to be the highest frequency?

10. Factors Affecting RADAR Range
Antenna Height
Ducting
Spreading
Absorption
Constructive vs Destructive Interference

11. Communications
LOS vs. OTH
Basic communications path