Pulse Flashcards
What is the time taken for a transmitting pulse to return?
The echo is proportional to the distance of the sound waves had to travel.
What does RADALT provide?
Provides height information for terrain directly below the aircraft.
What does the pulse Doppler radar determine?
Targets speed and direction of travel.
What is search radar used for?
Uses range and azimuth of target.
What is the continuous wave radar used for? (Missile control)
To illuminate the target with RF energy and usually shares the same antenna with the pulse radar.
In a radar block diagram, what component switches between transmitting and receiving?
Duplexer (Connects to the antenna).
When regarding the duplexer, what is the TR switch?
A TR switch is sensitive to the direction of flow of RF energy; it allows the energy coming from the transmitter to pass with negligible attenuation to the antenna, while blocking the flow to the receiver. In simple terms, it is a wave guide switch.
What are the 2 most common types of antennas?
- Parabolic (shape reflector) antenna (dish)
- Planar array
What is the parabolic (dish) antenna?
The parabolic antenna (also known as the ‘dish’ antenna) consists of a flared end section of waveguide (known as a ‘horn’) which directs RF energy onto a parabolic dish. The parabolic shape of the dish reflects the RF energy into a narrow beam.
What are the 3 main components of a parabolic (dish) antenna?
- Parabolic reflector
- Horn
- Radiated energy
What is the planar array?
Instead of employing a central feed that radiates the transmitted energy into a reflector, as in a parabolic antenna, a planar array consists of many individual slot radiators distributed over a flat surface.
C type display?
Elevation, Azimuth
Rotary joint - what is it?
Primary radar antenna is for a mechanical connection between a fixed section of waveguide and a section feeding a scanning antenna.
What component enables me to sample the transmitted RF energy?
Slot-Coupled Attenuator
Cannon plug and wave guide - Know the difference?
Be able to identify them by photos.
What does RADALT indicate?
Accurate reading at low altitude and low altitude warning.
How do we get a height indication on our RADLT system?
Transmit a CW and determine it off the time it takes to come back.
What component in the RADLT system loops my signal in test mode?
Delay unit / switch
How many pairs are there in the four beam Janice array?
2 pairs
Antenna array and rotor assembly - know the block diagram?
Know the block diagram.
Relevant frequencies for secondary surveillance radar?
The airborne transponder receives the interrogating signal from the ground station: 1030 MHz (and automatically arranges to transmit a response in reply). The reply is transmitted: 1090 MHz. In simple terms: 1030MHz transmit - 1090MHz reply.
How many antennas does a radar system have? And why?
2 antennas - 1 is transmit and 1 is receive.