EQPS - Radar Transmission Flashcards
2 main methods of removing unwanted returns in Primary Radar (2)
- MTI - Moving Target Indicator
- CP - Circular Polarisation
What is CP? (2)
CP - Circular Polarisation
Electromagnetic Waves (EMF) utilised by the RADAR to overcome the effect of Weather clutter
What is MTI? (2)
MTI - Moving Target Indicator
- Fitted in PSR
- Displays echoes from moving targets (Aircraft)
- Reject echoes from fixed targets (Permanent objects)
What is Tangential Fading? (1)
A condition in which a target does not appear on the radar screen when it is moving tangentially to the radar while using an MTI
What is Blind Velocity Fading? (1)
When the aircraft is flying directly towards, or directly away from, the radar scanner
What are the different types of Data transmission? (4)
- Coaxial cable
- Radio link
- Telephone link
- Fibre Optics
Data transmission diagram
Characteristics of Coaxial Cables (3)
- Limited to short distances
- Expensive
- Signal deteriorates rapidly
Characteristics of Radio link (3)
- Operates in the UHF - SHF frequency band
- Long distance information has to be monitored / repeated along the route
- Possible interference - Frequency is changed at each radio link repeater
Characteristics of Telephone link (3)
- May be used if they are of sufficiently high grade and the information is being sent in a processed form
- Can be used over considerable distances and they are comparatively cheap to maintain
- The use of plot extractors at radar sites, high grade transmission lines and suitable error checking processes enables a high standard of reliability to be maintained
Characteristics of Fibre Optics (1)
Used over relatively short distances
(e.g. between airfield radar site and the control tower)
What is Multi Radar processing? (3)
- Eliminating gaps in radar coverage
- Digitalised radar from all achievable radar is correlated and a composite (mosaic) picture covering the whole airspace is constructed
- Airspace is divided into a grid of squares 16nm by 16nm forming columns of air from the ground upwards (RADAR BOXES)
Multi Radar processing diagram
RADAR BOXES
What order does Radar give for its best cover? (2)
- Preferred
- Supplementary
Radar Coverage diagram
Digital Signal processing (multi radar sites) diagram
What does a Plot Extractor do? (8)
- Decides validity of targets
- Calculates correct azimuth and range data
- Decides if target is primary only, secondary only or combined
- Correlates code data in both identity and height modes
- Checks for emergency, radio fail, SPI indications, etc.
- Produces one complete target report per aircraft per aerial revolution and outputs this in digital form
- Produces synchronisation messages
- Produces north mark messages
What can past movement be displayed at on a Situation Display? (1)
Trail dots
Signal processing Diagram
What information can be included on a Video Map? (7)
- SIGNIFICANT POINTS - nav. aids, holding points, etc.
- FINAL APPROACH TRACKS with ranges
- AIRSPACE RESTRICTIONS
- CONTROLLED AIRSPACE BOUNDARIES
- COASTLINES & RIVERS
- FIR &NATIONAL BOUNDARIES
- LATITUDE & LONGITUDE
What are the different types of Moveable Data? (5)
- DF BEARING LINES
- ELECTRONIC RANGE & BEARING MARKER - ERBM
- ELECTRONIC CURSOR
- SYMBOLS
- ALPHA NUMERICS
