Radar Fundamentals Flashcards
What does RADAR stand for?
Radio Detection and Ranging
Identify
- Detects and tracks moving objects
- Operate day or night
- Operate in almost all weathers
- Has very broad coverage
Radar
Identify
30 MHz - 2 GHz
Radar Frequency Ranges and Applications
Search Radars
Identify
1 GHz - 8 GHz
Radar Frequency Ranges and Applications
Search & Track Radars
Identify
4 GHz - 18 GHz
Radar Frequency Ranges and Applications
Fire Control & Imaging Radars
Identify
8 GHz - 100+ GHz
Radar Frequency Ranges and Applications
Missile Seekers
Identify
- Transmitted Pulse
- Propagation
- Reflected Pulse “echo”
- Echo is recorded and output to a display
Principles of Operation
Identify
Amount of the radar signal intercepted or redirected back toward the radar
RADAR Cross-Section (RCS)
Identify
Measures how effective the target is in reflecting the radar signal
Target (RCS)
- Size
- Shape
- Orientation
- Composition
What does TEARR stand for?
- Time
- Elevation
- Azimuth
- Range
- Range-Rate
Identify
When a radar measurement is made and recorded
TEARR
Time
Identify
- Vertical Direction determination
- Measured from the horizontal plane
TEARR
Elevation
Describe Elevation and Azimuth Resolution
The farther the satellite, the better the resolution
Identify
- Horizontal Direction determination
- Measured from North
TEARR
Azimuth
Identify
The distance between the radar and the target
TEARR
Range
Identify
Combination of Total Power (Peak Power x Pulse Width) and Duty Cycle
TEARR
Radar Range
True or False
A long pulse width picks up small details
TEARR
False
True or False
A short pulse picks up finer details
TEARR
True
A long pulse can have the same bandwidth (resolution) as a short pulse by what?
Modulating in frequency of phase
These techniques allows to achieve energy of a long pulse and the resolution of a short pulse
The range resolution of radars is directly or inversely proportional to bandwidth?
Inversely
Identify
- How fast the target is moving towards or away from the radar
- Doppler Processing uses the frequency shift in echoed pulse to determine approach velocity
TEARR
Range Rate
Identify
- Single narrow beam
- Typically cued where to look
- Typically tracks only one object at a time
- Cheaper and easier to operate
- May produce imagery
RADAR Type
Mechanical Radar
Identify
- Only able to track one object at a time
- Difficulty with fast moving targets
- Images require expert analysis
- Susceptible to interference
- Easier to Jam
- Terrestrial Weather (High Winds/ Heavy Rain/Clutter)
- Atmospheric Conditions
RADAR Types
Mechanical Radar Limitations
Identify
- Very Agile
- High Antenna Gain
- Allows for scanning or search functions
- Uses beam steering and beam forming
- Track multiple objects
- Typically not used for imagery
RADAR Types
Phased Array Radar
Identify
Components that work to redirect the energy in a phased array radar
Phase Shifters
Identify
- Field of View (FOV) is limited to 120° Azimuth (per face)
- Expensive to build and operate
- Often more complex than mechanical
- UHF radars have lower resolutions
- Terrestrial Weather and Clutter
- Interference
RADAR Types
Phased Array Radar Limitations
Identify
- Used for imagery
- SLAR configuration
RADAR Types
Synthetic Aperture Radars (SAR)
Identify
Sources of Noise Received by RADAR
Radar Limitations
Identify
- Ionospheric Refraction
- Ionospheric Attenuation
- Ionospheric Dispersion
- Faraday Rotation
Radar Environmental Considerations
Identify
Bending closer the earth’s surface with distance away from the radar
Ducting
Identify
- Ground
- Sea
- Rain
- Birds and Insects
Clutter
Identify
- Chaffs
- Decoys
Countermeasures
