EO-6 Flashcards
What is the Radar Range Equation (RRE)?
An equation used to find the maximum range at which a radar can detect a target under a predetermined set of conditions.
Define power transmitted
a pulse transmitted with a certain amount of power, determined by the transmitter.
what is power transmitted measured in?
watts
as power moves away from an antenna, it will cover an increasingly larger surface area calculated as what?
4 pi R squared
what is power density (Pt)?
the amount of power transmitted, spread over the surface area at that range.
What is power density measured in?
Meters
what is antenna gain (G)?
the amount of power sent in a particular direction, as compared to that which would have been sent in that direction with an isotropic antenna.
what is antenna gains unit of measure
it is unitless, it is a ratio
What is Radar Cross Section (RCS)?
is used to estimate the surface area that will collect and re-radiate the signal power back to the radar system. (represented by the Greek character sigma)
What is the radar cross section (RCS) measured in?
Square meters
T/F. The actual area of the antenna is not the same as the effective aperture size (Aeff).
True. Unfortunately, no antenna is 100% efficient.
Define the number of pulses integrated (N)?
in the signal processor, there may be a number of pulses integrated in the pulse integrator, they are represented by the letter n.
In the radar range equation, what does R-max represent?
The maximum range a radar can detect targets
In the radar range equation, what does S-min represent?
The smallest received signal that can be detected
Noise within the receiver can be calculated by what formula?
Noise=kTBF
k (boltzmann constant) is equal too?
1.38 ×10 ^-23 J/K. J stands for Joules, K stands for Kelvins.
What is the Boltzmann constant?
gives a measure of the rate at which energy will fluctuate at certain temperatures.
T represents what in the noise equation?
absolute temperature. (measured in kelvins)
B represents what in the in the noise equation?
reciever bandwidth
T/F The smaller the bandwidth of the reciever, the more noise will be added to the signal.
False. the greater the bandwidth the more noise will be added
Noise factor (F)
a measure of the amount of the degradation of the signal as it passes through the receiver. (comparison of the input signal to the output signal, i.e. ratio)
Noise figure (NF)
the noise factor expressed in dB
Smin is dependent on what?
The noise value. (It must be greater than the noise in order for the radar to detect a target)
What is the SNRmin based on?
Desired probability of detection, probability of false alarm
What factor makes the Smin greater than the noise?
The SNRmin
