Lesson 308 Radar Imagery Theory Flashcards
What does the acronym RADAR mean?
Radio detection and ranging
What principle is RADAR based on?
RADAR is based on the idea of reflected energy. The stronger the reflected signal, the larger the particle.
List the 5 components of a RADAR system.
TRAPD
Transmitter Receiver Antenna Processor Display
What do the abbreviations PPI and CAPPI stand for?
Plan Position Indicator
Constant Altitude Plan Position Indicator
What are Echo Tops?
A representation of the highest altitude where detectable precipitation is observed.
Define wavelength.
The distance from crest to crest or trough trough in a wave train.
Define frequency
The path that the wave travels in one wavelength is called a cycle and the number of cycles in a given unit of time (1 second) is called the frequency.
Define propagation
Normal RADAR energy refracted with the earth’s curvature approximately 4/3 that of the earth.
List in order the reflective capabilities of hydrometeors.
LRSSC
Large hail >80% of wavelength Rain Small hail <20% of wavelength Snow Clouds
Define Attenuation and list the three types
SAR
A lessening of the concentration of energy per unit volume of the beam.
Scattering
Absorption by atmospheric gases
Range
Define Distortion
Misrepresentations of the target in any of its parameters.
What are the 3 distortions due to RADAR design?
BPP
Beam width
Pulse length
Processor distortion
What are the 4 distortions due to propagation characteristics?
FREP
Fringing
Range
Earth curvature
Precipitation attenuation
What are extraneous echoes?
Any echo not derived from clouds or precipitation
What are the 3 types of extraneous echoes?
SAC
Second trip echoes
Angel echoes
Clutter
