Contemporary Topics in ECE 55:195, Spring 2006

Equations and Terms

Term	Details
Dead Zone
Range Resolution
PRF	Pulse Repetition Frequency
PRI	Pulse Repetition Interval = 1/PRF
Unambiguous range
Doppler shift
Unambiguous velocity
Doppler dilemma
Definition of radar reflectivity h (m2 m-3 )
Radar reflectivity h (m2 m-3 )
Definition of  radar reflectivity factor z (mm6/mm3)
Radar equation with incorporating simplified "lobing"
Radar equation with incorporating simplified "lobing" in region below first peak
Definition of refractivity	where n is the index of refraction
Distance to horizon (linear model of refractivity)
	where a = diameter of earth, ha is the antenna height and k = 4/3
Speed of radio wave

General Antenna Formulas

 

 Parabolic Dish Antennas

 

Radar Equation for Point Targets

Pt and Pr are transmitted and received power, s is the radar target cross sectional area, R is the distance between target and transmitter, and G is the antenna gain.

Radar Equation for Distributed Targets

	Pt is the transmitted and received power, h is the radar target cross sectional area, R is the distance between target and transmitter, and G is the antenna gain.  V is the radar pulse volume (see below)
Radar Pulse Volumes
	h = pulse length, t is the pulse width, q, and f are antenna beam widths.
	Radar equation for distributed targets using symmetric Gaussian antenna.  C is the radar constant.

Attenuation of electromagnetic energy in the atmosphere.  Solid curve is due to absorption by oxygen.  Dashed curve is due to absorption by water vapor.

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Last updated: 27-Apr-2006