Ace d' Base |
At the top of the profession, no one on the
site can better this fellow! |
AFC |
Automatic Frequency Control |
Agile |
A radar system capable of rapidly jumping
from one frequency to another. Used to defeat spot jamming. |
Airway |
Controlled airspace in the form of a road
in the sky. In the UK the airway is usually identified by a colour and a number
ie Red 01, Green 15 etc. (A rich source of targets) |
AMES |
Air Ministry Experimental Station, as in AMES
Type 80 and so on. |
AN/FPS-3 |
US built
search radar. |
AN/FPS-6 |
US built height finding radar. AKA "Nodding
Horror" |
AN/xxx-xx |
US military equipment designation - see next
glossary
page for full details |
Ana-Prop |
Anomalous Propagation of radar signals that
causes ground returns and targets to be seen out to greater than normal distances
- or not at all!. Often caused by refraction of the signal in the atmosphere
in regions of high pressure |
Angels |
Height in thousands of feet, ie Angels 15
= 15,000 feet. (This term was also used in the early days of radar to describe
returns caused by large flocks of birds. In those days they didn't know what
caused these returns, so if they weren't aircraft they must be angels!) |
Azication |
Remote pointing of a nodding height-finder
in the direction of the target |
Barrage Jamming |
Broad band noise transmission directed by
a jammer at a radar with the intention of rendering the radar ineffective. Usually
used against Agile radars |
BFO |
Beat Frequency Oscillator |
Blanking |
Suppression of video signals on a display
screen during the fly back stage of the trace, suppression of signals at trace
origin to remove close in permanent echoes. |
Blip |
Movie term for a return - never used by
professionals |
Blip Dip |
US term for a Scope Dope |
Blind Spot |
Area where targets may not be detected due
to screening by terrain |
Blind Zone |
See Blind Spot |
Blue Yeoman |
Code name for the British Type 85 air defence
search radar |
Bogie |
Enemy target |
Call Sign |
Name of radar site or the fighter
interceptor |
CFAR |
Constant False Alarm Rate |
Chaff |
Lengths of aluminium foil or fine wire dropped
by an aircraft to produce many confusing targets. Also known as "Window" |
Circ-Pol |
Circular Polarisation |
CIO |
Carrier Insertion Oscillator |
Clutter |
Permanent returns on radar displays caused
by mountains, pylons, buildings etc. |
Comms |
Communications |
Cone of silence |
Antenna systems are usually designed to radiate
towards the horizon, not vertically. Such designs can cause a region of attenuated
signal in a cone radiating up from the antenna. |
Cross-Pol |
Cross linear Polarisation |
CRT |
Cathode Ray Tube |
CW |
Continuous wave |
Dome |
A ball shaped enclosure used to protect a
radar antenna from the elements. Often called "Golf Balls" by the
media |
Duty Cycle |
Pulse Width x PRF |
Ducting |
See Ana-Prop |
Echo |
Returns, paints |
FAR |
False Alarm Rate |
Fish Pond |
A large CRT display approximately 1
Metre in diameter mounted so that its face was horizontal. Several people could
gather around the display |
Fruit |
Unwanted SSR returns received as a result
of a transponder reply to another interrogator. |
Garbling |
False codes displayed when aircraft are close
enough for their SSR responses to overlap. |
Golf Ball |
A newspaper name for a Radome. Also a form
of print head in a teleprinter |
Grass |
How noise appears when viewed on an oscilloscope,
a spectrum analyser or Type 'A' radar display |
Green Garlic |
Code name for the British Type 80 air defence
search radar |
Ground Returns |
Permanent returns on radar displays caused
by mountains, pylons, buildings etc. |
Head |
A radar antenna |
Hostile |
A non-friendly target Designated H-xxx on
the plotting board, the xxx indicating the track or raid number |
HSA |
The High Speed Aerial used in the British
RX12874 anti jamming equipment |
Interrogator |
The ground component of an SSR system. |
JAFAD
|
Just Another Flippin' Air Defence (technician) (clean
version! - Ed.). Generic term used to describe Air Defence technicians (AD's)
whose responsibilities, range of postings, promotion prospects and career paths
have been seriously eroded in the years since the split of the ground radar
trade in to Air Fields and Air Defence and the ending of the Cold War.
The angst of JAFAD's is legendary in the Royal Air Force.
|
Jammer |
An aircraft that transmits an interfering
transmission designed to confuse the operator or render a radar system
inoperable |
Jamming |
Interference on a radar display or the transmission
of signals designed to interfere with the radar's operation or to confuse the
operator |
Kaput |
Unserviceable, broken. (I believe this word
is of German origin) |
Klystron |
An amplifier valve. An electron stream is
direct through a series of cavities causing each cavity to resonate. The
RF
input is fed into the first cavity causing velocity modulation of the electron
stream . The successive resonating cavities amplify the velocity modulation,
resulting in a signal gain. The output is taken from the final cavity. A gain
of up to 40 dB can be achieved. |
L1 |
The central control station for the
British
"Linesman" air defence system. It was located at RAF West Drayton
in Middlesex, England, to the west of London. |
L-band |
A band of frequencies in the 23 cm or 1.5
GHz region |
Land Line |
The telephone |
Linesman |
British air defence radar system |
Link |
A circuit connecting two points |
Marconi S-259 |
An air transportable radar system |
Magnetron |
A radar transmitter valve. Electrons emitted
from a cathode follow spiral paths to the anode through a perpendicular magnetic
field. The anode contains a number of slotted cavities which resonate as the
electrons pass the slot. The magnetron is designed such that the power derived
from the oscillations from each cavity slot combine to produce an RF signal.
The RF energy is coupled by a stub to the wave guide system. |
Mediator |
British civil ATC application of "Linesman"
air defence system |
MBS |
Main Bang Suppression. A pulse that suppresses the
display video for the duration of the transmission pulse.
|
MRS |
Master Radar Station, the successor to
"Rotor" |
MTU |
Master Trigger Unit. Used to synchronise all
the radar transmitters at a particular site |
MTI |
Moving Target Indication. |
Nodding Horror |
AN/FPS-6 or HF200 Height finder radar |
Noise |
An undesired component of an electronic system.
In radar systems the received RF energy must be at a greater level than the
noise level of the system to be discernible |
Noise Jamming |
Broad band RF noise that can mask radar
targets. |
Noise Spokes |
The appearance of noise on particular bearings
on a PPI display resembling the spokes on a bicycle wheel |
OTH |
Over The Horizon |
Paint |
A radar return or echo (hardly ever called
a Blip - this is usually only used by hams and movie makers!) |
PDS |
A name given to the RX12874 anti jamming equipment
in the British "Linesman" air defence system meaning Passive Defence
System or Passive Detection System |
PDU |
Radar Photographic Development Unit. A system
that recorded, developed, fixed and dried photographic pictures of a radar
PPI
and then projected the image on to a large plotting table. Found in the R3 building
at MRS's |
PPI |
Plan Position Indicator |
PRF |
Pulse Repetition Frequency. The frequency
of pulse transmissions in a pulsed radar transmitter |
PRT |
Pulse Repetition Time - See PRF |
Pulse Width |
The duration of a pulse from rise time to
drop time |
PVR |
Premature Voluntary Retirement - Early termination
of engagement by RAF personnel. A term well known to JAFAD's (see above). |
R1, R2, R3, R4 etc. |
"Rotor" system buildings. Some were
buried below ground, others were on the surface or partially buried. |
Radar |
RAdio Detection
And Ranging |
Radome |
A ball shaped enclosure used to protect a
radar antenna from the elements |
Radial Velocity |
CW radar term describing the speed at which
a target is heading towards or away from the radar |
R.A.F. |
Royal Air Force, the world's first and oldest
military aviation armed force that was not a part of another armed service.
The R.A.F. was formed on April 1st 1918 from the Royal Flying Corps and the
Royal Naval Air Service. |
Railing |
The appearance of jamming on a radar
display |
RDF
|
Radio Direction Finding - the term used by Robert Watson
Watt to describe the technique that came to be known as Radar
|
Return |
The appearance of a target on a radar display,
the signal returning from the target. |
Rotor |
British air defence system in operation during
the late 40's to early 50's |
Royal Air Force |
See R.A.F. |
RF |
Radio Frequency |
RTB |
Return To Base |
RX12874 |
The Passive Detection ECCM anti jamming equipment
in the British "Linesman" air defence system |
S-Band |
A band of frequencies in the 10 cm or 3
GHz
region |
Scanner |
An inaccurate name for a rotating radar
antenna |
Scope Dope |
A radar operator, any operator, regardless
of rank. Important Note: This term does not apply
to the PDS technicians on the RX12874 system! |
Sector Scan |
Causing the radar to sweep back and forth
between two azimuth bearings rather than continuously rotating |
SGC |
Sensitivity Gain Control - see STC |
Side Lobe |
Unwanted lobes in a directional antenna |
Side Lobe Jamming |
A method of jamming a radar by transmitting
the jamming signal only as the side lobes pass the jammer, thus confusing the
operator as to the true bearing of the jammer |
Spoke |
The appearance of noise on particular bearings
on a PPI display resembling the spokes on a bicycle wheel |
Spoof |
Measures used to confuse the other side by
transmitting false information |
Spoof Jamming |
Measures used to confuse the other side by
transmitting false information. In radar terms this might involve transmitting
a carefully timed pulse into a radar's side lobes in an effort to produce false
returns on the radar display. |
Spot Frequency |
The frequency of a CW transmission |
Spot Jamming |
The transmission of a CW signal to jam a particular
frequency |
SSR |
Secondary Surveillance Radar. A ground based
interrogator transmitting at 1030 MHz triggers a response from an airborne transponder
transmitting at 1090 MHz. The coded reply can contain (amongst other things)
information about the identity and altitude of the aircraft carrying the
transponder. |
STC |
Sensitivity Time Control, Swept Time Control.
A method of varying the gain of a radar system such that signals from targets
close to the radar receiver are not amplified as much as signals from further
out. The gain is set to rise exponentially. Used on PPI systems to suppress
near-by clutter. |
Steely Blue Eyed Ace |
A pilot. Pilots fly Targets, Targets produce
Returns. |
Sun Spoke |
A spoke of noise on a radar PPI screen caused
by the Sun when it is low on the horizon |
Target |
The enemy, objects of interest on a radar
display |
Tac-Eval |
Tactical Evaluation. Several days of hell
inflicted on a unit on an annual basis to see if it is ready to go to war |
Trace Ace |
An exceedingly gifted scope dope (Very
rare!) |
The Hole |
An underground installation, particularly
"R3" bunkers at MRS's |
Theta/Phi display |
The "vertical raster" operators
display in the RX 12874 Passive Detection anti jamming ECCM system |
Transponder |
The airborne component of an SSR system. |
Type 80 |
British air defence search radar that came
into service in the early 50's and survived into the 90's. S-Band, 3 Mw (peak),
antenna rotated at 4 rpm, cosecant squared radiation pattern |
Type 84 |
British air defence search radar. This L-band
radar had an excellent MTI system. The antenna rotated at 4 rpm. |
Type 85 |
British air defence search radar. S-Band,
Twelve beam volumetric scan, antenna rotated at 4 rpm |
U/S |
Unserviceable, not working |
UKADR |
United Kingdom Air Defence Region |
Wave guide |
Hollow rectangular, oval or round tube used
to convey microwave RF energy from one point to another in a radar transmitter
or receiver |
Window |
Lengths of aluminium foil or fine wire dropped
by an aircraft to produce many confusing targets |
Wood Pecker |
The sound made by OTH radars when heard on
an HF communications receiver |
X-Band |
A band of frequencies in the 3 cm or 10 GHz
region |