EQPS - Radar Transmission

Question 1

2 main methods of removing unwanted returns in Primary Radar (2)

Answer 1

1. MTI - Moving Target Indicator
2. CP - Circular Polarisation

Question 2

What is CP? (2)

Answer 2

CP - Circular Polarisation

Electromagnetic Waves (EMF) utilised by the RADAR to overcome the effect of Weather clutter

Question 3

What is MTI? (2)

Answer 3

MTI - Moving Target Indicator

1. Fitted in PSR
2. Displays echoes from moving targets (Aircraft)
3. Reject echoes from fixed targets (Permanent objects)

Question 4

What is Tangential Fading? (1)

Answer 4

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

Question 5

What is Blind Velocity Fading? (1)

Answer 5

When the aircraft is flying directly towards, or directly away from, the radar scanner

Question 6

What are the different types of Data transmission? (4)

Answer 6

1. Coaxial cable
2. Radio link
3. Telephone link
4. Fibre Optics

Question 7

Data transmission diagram

Answer 7

Question 8

Characteristics of Coaxial Cables (3)

Answer 8

1. Limited to short distances
2. Expensive
3. Signal deteriorates rapidly

Question 9

Characteristics of Radio link (3)

Answer 9

1. Operates in the UHF - SHF frequency band
2. Long distance information has to be monitored / repeated along the route
3. Possible interference - Frequency is changed at each radio link repeater

Question 10

Characteristics of Telephone link (3)

Answer 10

1. May be used if they are of sufficiently high grade and the information is being sent in a processed form
2. Can be used over considerable distances and they are comparatively cheap to maintain
3. 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

Question 11

Characteristics of Fibre Optics (1)

Answer 11

Used over relatively short distances
(e.g. between airfield radar site and the control tower)

Question 12

What is Multi Radar processing? (3)

Answer 12

1. Eliminating gaps in radar coverage
2. Digitalised radar from all achievable radar is correlated and a composite (mosaic) picture covering the whole airspace is constructed
3. Airspace is divided into a grid of squares 16nm by 16nm forming columns of air from the ground upwards (RADAR BOXES)

Question 13

Multi Radar processing diagram

Answer 13

RADAR BOXES

Question 14

What order does Radar give for its best cover? (2)

Answer 14

1. Preferred
2. Supplementary

Question 15

Radar Coverage diagram

Answer 15

Question 16

Digital Signal processing (multi radar sites) diagram

Answer 16

Question 17

What does a Plot Extractor do? (8)

Answer 17

1. Decides validity of targets
2. Calculates correct azimuth and range data
3. Decides if target is primary only, secondary only or combined
4. Correlates code data in both identity and height modes
5. Checks for emergency, radio fail, SPI indications, etc.
6. Produces one complete target report per aircraft per aerial revolution and outputs this in digital form
7. Produces synchronisation messages
8. Produces north mark messages

Question 18

What can past movement be displayed at on a Situation Display? (1)

Answer 18

Trail dots

Question 19

Signal processing Diagram

Answer 19

Question 20

What information can be included on a Video Map? (7)

Answer 20

1. SIGNIFICANT POINTS - nav. aids, holding points, etc.
2. FINAL APPROACH TRACKS with ranges
3. AIRSPACE RESTRICTIONS
4. CONTROLLED AIRSPACE BOUNDARIES
5. COASTLINES & RIVERS
6. FIR &NATIONAL BOUNDARIES
7. LATITUDE & LONGITUDE

Question 21

What are the different types of Moveable Data? (5)

Answer 21

1. DF BEARING LINES
2. ELECTRONIC RANGE & BEARING MARKER - ERBM
3. ELECTRONIC CURSOR
4. SYMBOLS
5. ALPHA NUMERICS