FullDescription:Surveillance

ADS-C ETA min/max report

Link	Semantic Value
Term	ADS-C ETA min/max report
Status
Mandatory for
Contexts	SESAR
Categories
Synonyms
Related entries	Estimated Time of Arrival (ETA) Automatic Dependent Surveillance-Contract (ADS-C)
Broader term
Narrower term

Abbreviation

Definition

the ADS-C report containing the earliest and latest values of ETA computed by the aircraft system on the point specified by ATC (e.g. IAF).

Definition Source

SESAR Concept of Operations Step 2 Edition 2014 (Ed. 01.01.00)

Note

Lexicon Release

Lexicon Release 2015.1

ADS-C Extended Projected Profile

Link	Semantic Value
Term	ADS-C Extended Projected Profile
Status
Mandatory for
Contexts	SESAR
Categories
Synonyms	Automatic Dependent Surveillance-Contract Extended Projected Profile
Related entries	Automatic Dependent Surveillance-Contract (ADS-C) EPP data
Broader term
Narrower term

Abbreviation

ADS-C EPP

Definition

the ADS-Contract for EPP data.

Definition Source

SESAR Concept of Operations Step 1, Edition 2015

Note

Lexicon Release

Lexicon Release 2015.1

ATM Surveillance Tracker and Server

Link	Semantic Value
Term	ATM Surveillance Tracker and Server
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

ARTAS

Definition

a surveillance data processing and distribution system, designed to establish an accurate picture of the air situation of all traffic in a specific geographical area, and to distribute the relevant processed surveillance information to a community of user systems.

Definition Source

EUROCONTROL, Skyway magazine, 3, 11/1996, p.18

Note

ATS surveillance service

Link	Semantic Value
Term	ATS surveillance service
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	ATS surveillance system
Broader term
Narrower term

Abbreviation

Definition

A term used to indicate a service provided directly by means of an ATS surveillance system

Definition Source

ICAO, Official term and definition added to An 1 by Amdt 168 (2007), An 15 by Amdt 34 (2007) and PANS-ATM by Amdt 5 (2007)

Note

ATS surveillance system

Link	Semantic Value
Term	ATS surveillance system
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	ATS surveillance service
Broader term
Narrower term

Abbreviation

Definition

A generic term meaning variously, ADS-B, PSR, SSR or any comparable ground-based system that enables the identification of aircraft.

Definition Source

ICAO, Official term and definition added to An 1 by Amdt 168 (2007), An 4 by Amdt 54 (2007), An 15 by Amdt 34 (2007) and PANS-ATM by Amdt 5 (2007)

Note

Air Traffic Control Radar Beacon System

Link	Semantic Value
Term	Air Traffic Control Radar Beacon System
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar
Broader term
Narrower term

Abbreviation

ATCRBS

Definition

1. A surveillance radar system which uses transmitters/receivers (interrogators) and transponders.

2. a secondary surveillance radar system developed for use within the air traffic control system for more precise position reporting of planes. It is used in conjunction with the primary radar, which is used to determine the presence of planes in the airspace. ATCRBS supplements this positional information with positive identification and altitude information, allowing controllers to track each plane more precisely and efficiently.

Definition Source

1. EUROCONTROL, EATM glossary 2004

2. UNITED STATES (2000) "The Story of Mode S: An Air Traffic Control Data-Link Technology" (Emily Chang, Roger Hu, Danny Lai, Richard Li, Quincy Scott, Tina Tyan) [1]

Note

Aircraft address

Link	Semantic Value
Term	aircraft address
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A unique combination of twenty-four bits available for assignment to an aircraft for the purpose of air-ground communications, navigation and surveillance

Definition Source

ICAO/OACI, "International Civil Aviation Vocabulary", Doc. 9713, Vol.1, 1998

Note

Airport and Airways Surveillance Radar

Link	Semantic Value
Term	Airport and Airways Surveillance Radar
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

AASR

Definition

A medium range radar designed for both airway and airport surveillance applications.

Definition Source

Transport Canada, "TP 14371 - Transport Canada Aeronautical Information Manual (TC AIM)", GEN 5.1 Glossary of Aeronautical Terms [2]

Note

Automatic Dependent Surveillance

Link	Semantic Value
Term	Automatic Dependent Surveillance
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term	Automatic Dependent Surveillance-Contract Automatic Dependent Surveillance-Broadcast

Abbreviation

ADS

Definition

A surveillance technique in which aircraft automatically provide, via a data link, data derived from on-board navigation and position-fixing systems, including aircraft identification, four-dimensional position and additional data as appropriate.

Definition Source

ICAO (2010) Official definition, ANNEX 2 : Rules of the Air 2005; ANNEX 3 Meteorological Service for International Air Navigation 2010

Note

Automatic Dependent Surveillance-Broadcast

Link	Semantic Value
Term	Automatic Dependent Surveillance-Broadcast
Status
Mandatory for
Contexts	SESAR
Categories
Synonyms
Related entries	Automatic Dependent Surveillance-Contract
Broader term	Automatic Dependent Surveillance (ADS)
Narrower term

Abbreviation

ADS-B

Definition

A means by which aircraft, aerodrome vehicles and other objects can automatically transmit and/or receive data such as identification, position and additional data, as appropriate, in a broadcast mode via a data link.

Definition Source

ICAO, Official definition added to An 10/III by Amdt 76 (01/11/2001), to the PANS-ATM by Amdt 5 (2007) and modified by Amdt 40 to An 2 (2007) and Amdt 34 to An 15 (2007). Abbreviation and term added to PANS-ABC (Doc 8400) by Amdt 28 (2007).

Note

Lexicon Release

Lexicon Release 2015.2

Automatic Dependent Surveillance-Contract

Link	Semantic Value
Term	Automatic Dependent Surveillance-Contract
Status
Mandatory for
Contexts	SESAR
Categories
Synonyms	ADS contract
Related entries	Automatic Dependent Surveillance-Broadcast
Broader term	Automatic Dependent Surveillance (ADS)
Narrower term

Abbreviation

ADS-C

Definition

A means by which the terms of an ADS-C agreement will be exchanged between the ground system and the aircraft, via a data link, specifying under what conditions ADS-C reports would be initiated, and what data would be contained in the reports.

Definition Source

SESAR Concept of Operations Step 1, Edition 2015

Note

The abbreviated term “ADS contract” is commonly used to refer to ADS event contract, ADS demand contract, ADS periodic contract.

Lexicon Release

Lexicon Release 2015.1

CCAMS Code

Link	Semantic Value
Term	CCAMS Code
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	Centralised SSR Code Assignment and Management System (CCAMS)
Narrower term

Abbreviation

Definition

the SSR code that CCAMS has selected to the flight for the portion of the flight inside the CCAMS Area.

Definition Source

CCAMS User Requirements Document Vol 1

Note

Centralised SSR Code Assignment and Management System

Link	Semantic Value
Term	Centralised SSR Code Assignment and Management System
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR) Instrument Flight Rules (IFR) General Air Traffic (GAT) SSR code
Broader term
Narrower term

Abbreviation

CCAMS

Definition

[a tool that] centrally assigns SSR codes to all IFR/GAT flights that enter the CCAMS Area.

CCAMS will provide the assigned SSR code to the ATS Units along the route of the flight plan. The first ATS Unit in the CCAMS Area will assign the CCAMS Code to the flight concerned.

Definition Source

CCAMS User Requirements Document Vol 1

Note

Chain

Link	Semantic Value
Term	chain
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	chaining
Broader term
Narrower term

Abbreviation

Definition

(Reconstruction) A set of objects (e.g., plots and track updates) which belong to the same target and are correlated in space and time. They are associated to each other via aircraft identifier fields by the SASS-C Chaining process.

Definition Source

EUROCONTROL, Surveillance Analysis Support System for ATC-Centre: SASS-C Glossary [3]

Note

Chaining

Link	Semantic Value
Term	chaining
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	chain
Broader term
Narrower term

Abbreviation

Definition

(Reconstruction)

1. General. A process of linking together radar target reports (plots and tracks) and other information relating to one particular object.

2. SASS-C. All plots relating to the same target object are associated (chained) using the Object Correlator (OC). The chaining process allocates the same aircraft identity number to each plot which relates to one target object. Any plots which cannot be correlated to a target object are classified as unchained and are allocated a negative aircraft identification.

Definition Source

EUROCONTROL, Surveillance Analysis Support System for ATC-Centre: SASS-C Glossary [4]

Note

Clutter

Link	Semantic Value
Term	clutter
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	flying angel tracks
Broader term
Narrower term

Abbreviation

Definition

(Radar) A general term used for interfering reflections of radio energy in PSR from fixed or slow moving objects. There can be a number of different types of clutter:

- Ground clutter (generally not moving);

- Weather clutter (rain, snow, etc.);

- Sea clutter;

- Angel clutter (slow moving flocks of birds and anomalous propagation conditions).

Definition Source

EUROCONTROL, Surveillance Analysis Support System for ATC-Centre: SASS-C Glossary

Note

Clutter density

Link	Semantic Value
Term	clutter density
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	clutter
Narrower term

Abbreviation

Definition

The total number of unwanted Primary Radar echoes per nautical mile degree of the radar coverage area.

Definition Source

EUROCONTROL, Surveillance Analysis Support System for ATC-Centre (SASS), SASS-C Glossary

Note

Co-located

Link	Semantic Value
Term	co-located
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

An expression used for antennas which are at the same physical location, but may be on-mounted, back-to-back mounted, etc., and may use a common turning gear.

Definition Source

EUROCONTROL (1997) doc. "Radar Sensor Performance Analysis" SUR.ET1.ST03.1000-STD-01-01 [5]

Note

Coasting in blind zone

Link	Semantic Value
Term	coasting in blind zone
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	coasting track coasting on hold
Broader term	track
Narrower term

Abbreviation

Definition

A track for which the radar returns have been interrupted while being located inside an adapted blind zone.

Definition Source

U.S. Department of Transportation (2008) Federal Aviation Administration, Interface Control Document, Standard Terminal Automation Replacement System (STARS) To Airport Surface Detection Equipment – Model X (ASDE-X), NAS-IC-21053418-01D, Final [6]

Note

Coasting on hold

Link	Semantic Value
Term	coasting on hold
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	coasting track coasting in blind zone
Broader term	track
Narrower term

Abbreviation

Definition

A track for which the radar returns have been interrupted after being authorized to execute a holding procedure and being flagged “on hold” by the controller.

Definition Source

U.S. Department of Transportation (2008) Federal Aviation Administration, Interface Control Document, Standard Terminal Automation Replacement System (STARS) To Airport Surface Detection Equipment – Model X (ASDE-X), NAS-IC-21053418-01D, Final

Note

Coasting track

Link	Semantic Value
Term	coasting track
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	coasting on hold coasting in blind zone
Broader term	track
Narrower term

Abbreviation

Definition

A track for which the radar returns have been temporarily interrupted and whose position and altitude are being predicted and displayed based on the previously received radar and flight plan data.

Definition Source

U.S. Department of Transportation (2008) Federal Aviation Administration, Interface Control Document, Standard Terminal Automation Replacement System (STARS) To Airport Surface Detection Equipment – Model X (ASDE-X), NAS-IC-21053418-01D, Final [7]

Note

Code train

Link	Semantic Value
Term	code train
Status
Mandatory for
Contexts
Categories
Synonyms	reply code reply pulse train
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

A sequence of bracket (framing) and information pulses in an SSR Mode A or Mode C reply.

Definition Source

ICAO, DOC 9684 Manual of the Secondary Surveillance Radar (SSR) Systems 2004, Glossary

Note

Collimation

Link	Semantic Value
Term	collimation
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	primary surveillance radar (PSR) secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

The process of calculating the bias model parameters describing the systematic errors between the measurements of two co-located radar (e.g., PSR and SSR)

Definition Source

EUROCONTROL (2010) SASS-C Glossary [8]

Note

Combination criteria

Link	Semantic Value
Term	combination criteria
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The criteria with respect to azimuth and range coincidence which a primary radar plot and an SSR plot must meet to be considered to have come from the same aircraft and therefore to be able to be combined.

Definition Source

EUROCONTROL (1997) doc. "Radar Sensor Performance Analysis" SUR.ET1.ST03.1000-STD-01-01 [9]

Note

Combined target report

Link	Semantic Value
Term	Combined target report
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	primary surveillance radar (PSR) secondary surveillance radar (SSR)
Broader term	target report
Narrower term

Abbreviation

Definition

A target report detected by both PSR and SSR and such that both detections were sufficiently adjacent to be combined into one target report.

Definition Source

EUROCONTROL (1997) doc. "Radar Sensor Performance Analysis" SUR.ET1.ST03.1000-STD-01-01 [10]

Note

Cone of silence

Link	Semantic Value
Term	cone of silence
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A gap in coverage above a radar due to the limitations of the antenna performance at high elevation angles.

Definition Source

EUROCONTROL (1997) doc. "Radar Sensor Performance Analysis" SUR.ET1.ST03.1000-STD-01-01 [11]

Note

Confidence

Link	Semantic Value
Term	confidence
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

(Track Analysis) Tracker provided value that indicates the certainty of a Track or Mode of Flight.

Definition Source

EUROCONTROL (2010) SASS-C Glossary

Note

Confirmed track

Link	Semantic Value
Term	confirmed track
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	track
Narrower term

Abbreviation

Definition

Track with a high Confidence (above a tracker dependent threshold).

Definition Source

EUROCONTROL (2010) SASS-C Glossary

Note

Control antenna

Link	Semantic Value
Term	control antenna
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

An SSR antenna having a polar diagram which is designed to “cover” the side lobes of the main interrogating antenna. It is used to radiate a control pulse which, if it exceeds in amplitude the associated interrogation signal at the input to the transponder, will cause the transponder to inhibit responses to the interrogation pulses. Modern SSR antennas have the control elements built into the main array. The control antennas is also known as the SLS (side-lobe suppression) antenna.

Definition Source

ICAO (2004) doc. 9684, Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Control pattern

Link	Semantic Value
Term	control pattern
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	control antenna
Broader term
Narrower term

Abbreviation

Definition

A polar diagram of the control antenna. Modern integrated SSR antennas have a “modified cardioid” beamshape.

Definition Source

ICAO (2004) doc. 9684, Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Control pulse

Link	Semantic Value
Term	control pulse
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A pulse (P2 for Modes A and C, P5 for Mode S) transmitted by the ground equipment (SSR interrogator) in order to ensure side-lobe suppression.

Definition Source

ICAO (2004), doc. 9684, Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Correlated tracks

Link	Semantic Value
Term	correlated tracks
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	flight plan
Broader term
Narrower term

Abbreviation

Definition

Tracks which have been correlated with a flight plan (sometimes this term applies only to tracks for which the Mode A code has been correlated with a call-sign in the code/call-sign list i.e. flight plan association).

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Cosecant-squared antenna

Link	Semantic Value
Term	cosecant-squared antenna
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

An antenna pattern for which the gain is proportional to the square of the cosecant of the elevation angle. This results in an approximately constant signal, as a function of range, from an aircraft at constant flight level.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Coverage

Link	Semantic Value
Term	coverage
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

1. (radio-navigation) The coverage provided by a radio-navigation system is that surface area or space volume in which the signals are adequate to permit the user to determine position to a specified level of accuracy.

Coverage is influenced by system geometry, signal power levels, receiver sensitivity, atmospheric noise conditions and other factors which affect signal availability.

2. (general) "feature that acts as a function to return values from its range for any direct position within its spatial, temporal, or spatiotemporal domain.

EXAMPLE: Examples include a raster image, polygon overlay or digital elevation matrix.

NOTE: In other words, a coverage is a feature that has multiple values for each attribute type, where each direct position within the geometric representation of the feature has a single value for each attribute type."

Definition Source

1. ICAO Document 9613, Manual on Required Navigation Performance (RNP), Appendix A

2. ISO Standard 19123 (Geographic Information - Schema for coverage geometry and functions) (2005)

Note

Coverage measurement volume

Link	Semantic Value
Term	coverage measurement volume
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

CMV

Definition

the three dimensional volume of Airspace within which the performance and availability requirements will be analysed during a particular measurement campaign.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Data link

Link	Semantic Value
Term	data link
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Data link authority
Broader term
Narrower term

Abbreviation

Definition

(in common channel signalling) "a combination of two data channels operating at the same data rate but in opposite directions"

Definition Source

International Electrotechnical Commission (IEC), Electropedia database[12]

Note

Data link initiation capability

Link	Semantic Value
Term	data link initiation capability
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	data link
Narrower term

Abbreviation

DLIC

Definition

A data link application that provides the ability to exchange addresses, names and version numbers necessary to initiate data link applications.

Definition Source

ICAO, Official definition, Procedures for Air Navigation Services — Air Traffic Management [ICAO Doc 4444, PANS-ATM] 2004

Note

Dead time

Link	Semantic Value
Term	dead time
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Secondary surveillance radar transponder
Broader term
Narrower term

Abbreviation

Definition

A period of time during which an SSR transponder is inhibited from receiving signals after a valid interrogation is received and a reply transmitted. The term is also used to describe the time after the normal range for returns and before the next transmission from an interrogator or from a primary radar system.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Defruiting

Link	Semantic Value
Term	Defruiting
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Interrogator Repetition Frequency
Broader term
Narrower term

Abbreviation

Definition

A process by which aircraft replies accepted by the interrogator-responsor are tested by means of storage and a comparator for synchronism with the interrogation-repetition frequency. Only replies which are in synchronism (correlate on a repeated basis in range) will be output from the defruiter. Other replies are rejected as “fruit” or false.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Degarbling

Link	Semantic Value
Term	Degarbling
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	garbling
Broader term
Narrower term

Abbreviation

Definition

A process of separating (and possibly validating) garbled SSR replies

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Delta theta

Link	Semantic Value
Term	delta theta
Status
Mandatory for
Contexts
Categories
Synonyms	plot run length azimuth extension
Related entries
Broader term
Narrower term

Abbreviation

Definition

A number of azimuth count pulses (ACPs) as measured from the plot leading edge to the plot trailing edge in a sliding window plot extractor. Also known as azimuth extension or plot run length.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Difference pattern

Link	Semantic Value
Term	Difference pattern
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	off-boresight angle sum pattern
Broader term
Narrower term

Abbreviation

Definition

A receive (1 090 MHz) characteristic of a monopulse SSR antenna, obtained by connecting in antiphase the signals (replies) received by two partial antennas. The difference pattern has a minimum in the main radiation direction of the antenna and an amplitude and phase characteristic which varies as a function of angle of arrival of the received signal. Used in conjunction with the sum output of the antenna, it enables the off-boresight angle to be found.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Doppler shift

Link	Semantic Value
Term	Doppler shift
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The frequency shift observed at a receiver due to any relative motion between transmitter and receiver.

Definition Source

ICAO (2006) Official definition, ANNEX 10/III Aeronautical Telecommunications — Part I, Digital Data Communication Systems; Part II, Voice Communications Systems

Note

Doppler speed

Link	Semantic Value
Term	Doppler speed
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The radial (to the radar sensor) velocity of a target (aircraft) or of a clutter source (false alarm) measured from its Doppler frequency shift in a received primary radar return.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Downlink

Link	Semantic Value
Term	Downlink
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A term referring to the transmission of data from an aircraft to the ground. Mode S air-to-ground signals are transmitted on the 1 090 MHz reply frequency channel.

Definition Source

ICAO, Official definition:

ANNEX 10/III Aeronautical Telecommunications — Part I, Digital Data Communication Systems; Part II, Voice Communications Systems 1995, 1st ed., Amdt. 77 (27/02/2002), p. 5-1

DOC 9871 Technical Provisions for Mode S Services and Extended Squitter 2008, 1st ed., p. (x)

Note

Duplicate extractor monitoring message

Link	Semantic Value
Term	Duplicate extractor monitoring message
Status
Mandatory for
Contexts
Categories
Synonyms	Duplicate EMM
Related entries	Extractor Monitoring Message (EMM) Mean antenna revolution time
Broader term
Narrower term

Abbreviation

Definition

If an Extractor Monitoring Message (EMM) is received before (Mean antenna Revolution time -30%) AND (45' of the expected EMM position) a Duplicate EMM condition exists.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Duplicated secondary surveillance radar coverage

Link	Semantic Value
Term	duplicated secondary surveillance radar coverage
Status
Mandatory for
Contexts
Categories
Synonyms	Duplicated SSR coverage
Related entries
Broader term
Narrower term

Abbreviation

Definition

a given point in space for which the radar data used by an ATS unit for the surveillance function are derived from at least two independent SSR sources working simultaneously

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Effective radiated power

Link	Semantic Value
Term	Effective radiated power
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

ERP

Definition

1. the transmitted power enhanced by the gain of the antenna less the losses in cables, rotary joints, etc.

2. The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction.

Definition Source

1. ICAO, DOC 9684 Manual of the Secondary Surveillance Radar (SSR) Systems 2004

2. ICAO, DOC 9863 Airborne Collision Avoidance System (ACAS) Manual 2006

Note

Elevation angle

Link	Semantic Value
Term	elevation angle
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

the angle between the vector going from the radar head to the horizon on the one hand and the vector joining the radar head to a particular target on the other hand.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Entry

Link	Semantic Value
Term	entry
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The (moment of) crossing of an incoming track or trajectory with a predefined radar coverage area.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Equivalent isotropically radiated power

Link	Semantic Value
Term	equivalent isotropically radiated power
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

e.i.r.p.

Definition

The product of the power supplied to the antenna and the antenna gain in a given direction relative to an isotropic antenna (absolute or isotropic gain).

Definition Source

ICAO, Official definition, ANNEX 10/I Aeronautical Telecommunications — Radio Navigation Aids 1995, 5th ed., Chap. 3, p. 27

Note

Expected detections

Link	Semantic Value
Term	expected detections
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

(plot analysis) expectation for Primary Radar (PR) and/or secondary surveillance radar (SSR) detections for a target which is determined by using the following concepts : miss generation volume; terrain visibility; cone of silence; transponder existence on the target.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Extended length message

Link	Semantic Value
Term	Extended length message
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Comm-C
Broader term
Narrower term

Abbreviation

ELM

Definition

A series of Comm-C interrogations (uplink ELM) transmitted without the requirement for intervening replies, or a series of Comm-D replies (downlink ELM) transmitted without intervening interrogations.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Extractor

Link	Semantic Value
Term	extractor
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	plot extractor
Broader term
Narrower term

Abbreviation

Definition

equipment that converts radar pulses into digitised radar data.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Extractor Monitoring Message

Link	Semantic Value
Term	Extractor Monitoring Message
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	duplicate extractor monitoring message
Broader term
Narrower term

Abbreviation

EMM

Definition

Processing status message, correlated to the North Signal.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

False plot

Link	Semantic Value
Term	false plot
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	plot
Narrower term

Abbreviation

Definition

A radar plot report which does not correspond to the actual position of a real aircraft (target), within certain limits.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

False plot analysis

Link	Semantic Value
Term	false plot analysis
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	false plot
Narrower term

Abbreviation

Definition

A SASS-C analysis application which provides a means of identifying the quantity and characteristics of false plots in a radar system.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

False track

Link	Semantic Value
Term	false track
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

1. Track initiated on false SSR/PR as side lobe, reflection, second time around, angel or clutter plot.

2. A track formed from erroneous surveillance data that indicates an intruder where none exists.

Definition Source

1. EUROCONTROL (2001) EATM Glossary

2. ICAO, Cir.195, 1985, p. 68

Note

Flying angel tracks

Link	Semantic Value
Term	flying angel tracks
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

"primary radar echo caused by a moving atmospheric refraction, atmospheric in homogeneity, insects, birds etc."

Definition Source

NORTH ATLANTIC TREATY ORGANISATION RESEARCH AND TECHNOLOGY ORGANISATION

(2005)

AC/323(SET-063)TP/49 RTO EDUCATIONAL NOTES EN SET-063

Knowledge-Based Radar Signal and Data Processing

Note

Framing pulses

Link	Semantic Value
Term	framing pulses
Status
Mandatory for
Contexts
Categories
Synonyms	bracket pulses
Related entries
Broader term
Narrower term

Abbreviation

Definition

Pulses which “frame” the information pulses (code) of SSR Mode A and C replies (described as F1 and F2 respectively).

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Fringe envelope

Link	Semantic Value
Term	fringe envelope
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

the intersection of the vertical plane passing from the Radar Sensor and the actual coverage. It defines the limits within which the system satisfies the specified performance and availability requirements.

Definition Source

EUROCONTROL (1997) Radar Sensor Performance Analysis, doc. SUR.ET1.ST03.1000-STD-01-01

Note

Fruit

Link	Semantic Value
Term	Fruit
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A term applied to unwanted SSR replies received by an interrogator which have been triggered by other SSR interrogators. Fruit is the acronym of False Replies Unsynchronized In Time, or False Replies Unsynchronized to Interrogator Transmission.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Gain of antenna

Link	Semantic Value
Term	gain of antenna
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A measure for the antenna of the increased (effective) transmitted power density radiated in a particular direction as compared to the power density that would have been radiated from an isotropic antenna (expressed in dB).

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Garbled Mode C

Link	Semantic Value
Term	garbled Mode C
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Garbled mode A
Broader term
Narrower term

Abbreviation

Definition

The condition of the Mode C in the original format is regarded as garbled.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Garbled mode A

Link	Semantic Value
Term	Garbled mode A
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	garbled Mode C SSR Mode A
Broader term	garbling
Narrower term

Abbreviation

Definition

The condition of the Mode A in the original format is regarded as garbled.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Garbling

Link	Semantic Value
Term	Garbling
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Degarbling
Broader term
Narrower term

Abbreviation

Definition

A term applied to the overlapping in range and/or azimuth of two or more SSR replies so that the pulse positions of one reply fall close to or overlap the pulse positions of another reply, thereby making the decoding of reply data prone to error.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Ground radar

Link	Semantic Value
Term	ground radar
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

radar installed on top of the Control Tower and used in foggy weather, it provides a ground image of the airport. Vehicles and aeroplanes are clearly shown including airborne aircraft below 200 feet.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Ground-initiated Comm-B protocol

Link	Semantic Value
Term	Ground-initiated Comm-B protocol
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Comm-B
Broader term
Narrower term

Abbreviation

GICB

Definition

A procedure initiated by a Mode S ground station for eliciting a Comm-B message from a Mode S airborne installation.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Heading

Link	Semantic Value
Term	heading
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The direction, in which the longitudinal axis of an aircraft is pointed, expressed in clockwise degrees from North. Usually magnetic heading (with respect to the magnetic North Pole), sometimes true heading (with respect to the geographic North Pole).

Definition Source

EUROCONTROL SASS-C Glossary

Note

Height Monitoring Unit

Link	Semantic Value
Term	Height Monitoring Unit
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR) Altimetry system error
Broader term
Narrower term

Abbreviation

HMU

Definition

A system capable of measuring the geometric height of an aircraft for comparison with the geometric height of the flight level at which it is being flown.

Definition Source

EUROCONTROL EATMP Glossary, June 2001

Note

additional definition taken from the EUROCONTROL SASS-C Glossary:

The HMU is a passive ground based system that measures aircraft height keeping within its area of cover. Each system consists of a set of ground stations arranged as a central site with four additional receivers arranged in a square. Each site receives aircraft SSR replies (Modes A, C and S) from which the 3D position of the aircraft is derived. Using meteorological information and the Mode C/S height data it is possible to calculate the altimeter system error.

Hit

Link	Semantic Value
Term	hit
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A reception by the aircraft equipment (transponder) of one usable set of interrogation pulses as evidenced by a reply code return (i.e. receipt of 2 interrogation pulses and 1 control pulse).

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Horizontal Polar Diagram

Link	Semantic Value
Term	Horizontal Polar Diagram
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

HPD

Definition

a polar plot of the antenna's radiation pattern taken in the horizontal plane.

Definition Source

EUROCONTROL (1997) Radar Sensor Performance Analysis, doc. SUR.ET1.ST03.1000-STD-01-01

Note

Improved interrogation side-lobe suppression

Link	Semantic Value
Term	Improved interrogation side-lobe suppression
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A technique whereby interrogation pulse P1 is transmitted via both the main beam and the control beam of the SSR antenna, so that a transponder in a side-lobe direction more reliably receives a P1-P2 pulse pair.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Input

Link	Semantic Value
Term	input
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	input characteristics input class
Broader term
Narrower term

Abbreviation

Definition

(Track analysis) Plot information being input for the tracker.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Input characteristics

Link	Semantic Value
Term	input characteristics
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	input class
Broader term	input
Narrower term

Abbreviation

Definition

Quantities describing the tracker input information in terms of the Mode Of Flight, the Plot Quality parameters etc... Tracker performance can be measured for Constant Input Characteristics, referring to the tracker input being constant with respect to Mode Of Flight or Plot Quality parameters.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Input class

Link	Semantic Value
Term	input class
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	input characteristics
Broader term	input
Narrower term

Abbreviation

Definition

A selected set of chains, tracks and trajectories based on a classification input criterion.

Definition Source

EUROCONTROL (2001) EATM Glosary

Note

Interlace

Link	Semantic Value
Term	interlace
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A repeating series of SSR interrogation modes. The interlace pattern may be determined either on a p.r.p. (pulse-repetition period) to p.r.p. basis or on an antenna rotation to antenna rotation basis. It may also be made on a combined p.r.p./antenna basis.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Interleave

Link	Semantic Value
Term	interleave
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	pulse train
Broader term
Narrower term

Abbreviation

Definition

A condition where two or more pulse trains become superimposed in time so that their pulse time spacing can be distinguished and the correct codes established.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Interrogator

Link	Semantic Value
Term	interrogator
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The ground-based surveillance radar beacon transmitter-receiver, which normally scans in synchronism with a primary radar, transmitting discrete radio signals which repetitiously request all transponders on the mode being used to reply. The replies received are mixed with the primary radar returns and displayed on the same plan position indicator (radar scope). Also, applied to the airborne element of the TACAN/DME system.

Definition Source

FAA (2010) Pilot/Controller Glossary [13]

Note

Interrogator Repetition Frequency

Link	Semantic Value
Term	Interrogator Repetition Frequency
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Pulse Repetition Frequency
Broader term
Narrower term

Abbreviation

IRF

Definition

An average number of interrogations per second transmitted by the radar. (See also “Pulse Repetition Frequency”.)

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Interrogator side-lobe suppression

Link	Semantic Value
Term	Interrogator side-lobe suppression
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	side-lobe suppression
Narrower term

Abbreviation

ISLS

Definition

A method of preventing transponder replies to interrogations transmitted through the ground antenna side lobes.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Interrogator-responsor

Link	Semantic Value
Term	interrogator-responsor
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	interrogator
Broader term
Narrower term

Abbreviation

Definition

A ground-based combined transmitter-receiver element of an SSR system.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Inventory analysis

Link	Semantic Value
Term	inventory analysis
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The inventory analysis consists of the Radar Statistics program (also referred to as RASTA) and four graphics inventory programs. For Mode S purposes four additional displays are existing.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Leading edge

Link	Semantic Value
Term	leading edge
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	trailing edge
Broader term
Narrower term

Abbreviation

Definition

1. (Surveillance) "Front edge of a pulse."

2. (aircraft) "The forward edge of an aerofoil or other body moving through the air."

Definition Source

1. EUROCONTROL SASS-C Glossary

2. Agard Multilingual Aeronautical Dictionary

Note

Lobing

Link	Semantic Value
Term	Lobing
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

(antenna pattern) A process whereby, due to interference of two waves, one direct and one reflected, differences in phases cause larger or smaller amplitudes than expected for free space, causing differences in signal amplitudes.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Local code

Link	Semantic Value
Term	local code
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR code
Broader term
Narrower term

Abbreviation

Definition

a SSR code from a pool of codes not managed by CCAMS (i.e. available to ATS Units only). This code can be assigned by ATS Units to flights in special circumstances, e.g. when the ATS Unit has not received a CCAMS Code in time. Each ATS unit will have its own pool of Local Codes.

Definition Source

CCAMS User Requirements Document Vol 1

Note

Local track

Link	Semantic Value
Term	local track
Status
Mandatory for
Contexts
Categories
Synonyms	mono track
Related entries	system track
Broader term
Narrower term

Abbreviation

Definition

an aircraft trajectory calculated from plots received during several rotations of one radar antenna

Definition Source

EUROPEAN COMMUNITY (2000) COMPETITIVE AND SUSTAINABLE GROWTH PROGRAMME, INTENT WP 3 Implementation Roadmap, p. 27 (tracking) [14]

Note

Main track

Link	Semantic Value
Term	main track
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

(track analysis) A track which existed before and after a multiple track event, i.g. in an extra track event.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Mean antenna Revolution time

Link	Semantic Value
Term	mean antenna revolution time
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Extractor Monitoring Message (EMM)
Broader term
Narrower term

Abbreviation

Definition

The time between reception of the first EMM and the last EMM divided by the total number of antenna rotations.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Miss generation volume

Link	Semantic Value
Term	miss generation volume
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	expected detections
Broader term
Narrower term

Abbreviation

Definition

An intentionally introduced term to define miss allocation space. Currently it is defined by the PR or SSR maximum range.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Mode

Link	Semantic Value
Term	mode
Status
Mandatory for
Contexts
Categories
Synonyms	SSR mode
Related entries	SSR Mode A SSR Mode C SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

The conventional identifier related to specific functions of the interrogation signals transmitted by an SSR interrogator.

Definition Source

ICAO, Official definition, PANS-ATM Procedures for Air Navigation Services — Air Traffic Management [Doc 4444] 2001, 14th ed., Chap. 1

Note

There are four modes specified in Annex 10: A, C, S and intermode.

Mode C out of spec

Link	Semantic Value
Term	Mode C out of spec
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode C
Broader term
Narrower term

Abbreviation

Definition

A Mode C is said to be out of spec if it is less than FL- 12 parameters or greater than FL700 parameters.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Mode S

Link	Semantic Value
Term	Mode S
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

An enhanced mode of SSR that permits selective interrogation and reply capability.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Whilst traditional Secondary Surveillance Radar (SSR) stations interrogate all aircraft within their range, Mode S establishes selective and addressed interrogations with aircraft within its coverage. Such selective interrogation improves the quality and integrity of the detection, identification and altitude reporting. These improvements translate into benefits in terms of safety, capacity and efficiency - benefits which are key to supporting the future of the high-traffic density airspace of Europe.

Note Source

EUROCONTROL, CFMU Glossary, Sept. 2011

Mode S all call

Link	Semantic Value
Term	Mode S all call
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

Interrogation to all Mode S equipped aircraft. It is used by Mode S sensor to acquire the Mode S addresses of the aircraft in its coverage.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Mode S radar

Link	Semantic Value
Term	Mode S radar
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

"A co-operative surveillance and communication system that has been designed as an evolutionary improvement to the existing SSR system. With a Mode S radar, only one scheduled surveillance interrogation and one reply are required on every antenna scan to accurately track the aircraft. Each aircraft reply has a unique 24 bit mode S address permanently associated with the aircraft."

Definition Source

EUROCONTROL SASS-C Glossary

Note

Mode S roll call

Link	Semantic Value
Term	Mode S roll call
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

Addressed UF 4, 5, 20, 21 or 24 Mode S interrogation or DF 4, 5, 20, 21 or 24 transponder reply.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Mode S specific protocol

Link	Semantic Value
Term	Mode S specific protocol
Status
Mandatory for
Contexts
Categories
Synonyms	Mode select specific protocol
Related entries
Broader term	Mode S
Narrower term

Abbreviation

MSP

Definition

A protocol that provides restricted datagram service within the Mode S subnetwork.

Definition Source

ICAO (1995) Official definition, ANNEX 10/III Aeronautical Telecommunications — Part I, Digital Data Communication Systems; Part II, Voice Communications Systems 1995, 1st ed., p. 5-2

Note

Mode S subnetwork

Link	Semantic Value
Term	Mode S subnetwork
Status
Mandatory for
Contexts
Categories
Synonyms	Mode select sub network
Related entries
Broader term	Mode S
Narrower term

Abbreviation

Definition

A means of performing an interchange of digital data through the use of secondary surveillance radar (SSR) Mode S interrogators and transponders in accordance with defined protocols.

Definition Source

ICAO (1995) Official definition, ANNEX 10/III Aeronautical Telecommunications — Part I, Digital Data Communication Systems; Part II, Voice Communications Systems

Note

Mode S target report

Link	Semantic Value
Term	Mode S target report
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

those target reports capable of passing the standard Mode S default filter.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Monopulse

Link	Semantic Value
Term	monopulse
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A technique wherein the amplitudes and/or phases of the signals received in overlapping antenna lobes are compared to estimate the angle of arrival of the signal. The technique determines the angle of arrival of a single pulse, or reply, within an antenna beamwidth. The angle of arrival is determined by means of a processor using the replies received through the sum and difference patterns of the antenna.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

The monopulse technique is generally termed “monopulse direction finding”.

Multi Radar Trajectory Reconstruction

Link	Semantic Value
Term	Multi Radar Trajectory Reconstruction
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

MURATREC

Definition

A suite of programs whose main functions are Estimation of the Systematic Errors present in radar plot data and calculation of accurate Trajectories for individual aircraft.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Multilateration system

Link	Semantic Value
Term	multilateration system
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	time difference of arrival (TDOA)
Broader term
Narrower term	wide area multilateration (WAM)

Abbreviation

MLAT

Definition

A group of equipment configured to provide position derived from the secondary surveillance radar (SSR) transponder signals (replies or squitters) primarily using time difference of arrival (TDOA) techniques. Additional information, including identification, can be extracted from the received signals.

Definition Source

ICAO (2010), ANNEX 10/IV Aeronautical Telecommunications — Surveillance Radar and Collision Avoidance Systems 2010, Amdt. 85

Note

Multipath

Link	Semantic Value
Term	multipath
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

Interference and distortion due to the presence of more than one path between transmitter and receiver.

Definition Source

EUROCONTROL (1997), "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

North message

Link	Semantic Value
Term	north message
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

Special message(s) generated by a plot extractor to indicate the passage of the antenna bore sight bearing through North.

Definition Source

EUROCONTROL SASS-C Glossary

Note

Object

Link	Semantic Value
Term	object
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A combination of radar targets and related information which are correlated in time and space.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Off-boresight angle

Link	Semantic Value
Term	off-boresight angle
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	boresight
Broader term
Narrower term

Abbreviation

OBA

Definition

In monopulse SSR, the angle (calculated by the OBA processor) by which a target is off (away from) the boresight (...), within the beamwidth of the antenna.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

On-site processing delay

Link	Semantic Value
Term	On-site processing delay
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The time expressed in seconds between the moment a radar target for a given aircraft is detected and the moment when the corresponding report starts to be transmitted.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Operational Coverage Volume

Link	Semantic Value
Term	Operational Coverage Volume
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

OCV

Definition

The airspace volume defined during the site commissioning of the Radar Sensor and in which radar services can be provided according to the local operational requirements.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Originating Region Code Assignment Method

Link	Semantic Value
Term	Originating Region Code Assignment Method
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Centralised SSR Code Assignment and Management System (CCAMS) participating area (PA)
Broader term
Narrower term

Abbreviation

ORCAM

Definition

method of allocating codes to States/units on a permanent basis to be assigned to flights

Definition Source

EUROCONTROL (2009) webpage "FAQ about CCAMS" [15]

Note

The Originating Region Code Allocation Method (ORCAM) is provided to permit a flight to respond on the same code to successive units within a participating area. (source: Commission Regulation (EC) No 2082/2000 of 6 September 2000 adopting Eurocontrol standards and amending Directive 97/15/EC, adopting Eurocontrol standards and amending Council Directive 93/65/EEC)

Over-interrogation

Link	Semantic Value
Term	over-interrogation
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

Interference in the operation of a secondary radar system due to the fact that the number of interrogations exceeds the capacity of the transponder (a preset value). The action of the transponder is an automatic reduction in transponder receiver sensitivity.

Definition Source

ICAO (2004), doc. 9684, Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Participating area

Link	Semantic Value
Term	participating area
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Originating Region Code Assignment Method (ORCAM)
Broader term
Narrower term

Abbreviation

PA

Definition

An area of specified dimensions comprising the areas of ATS responsibility of several States wherein a four-digit code assigned to a specific aircraft engaged in an international flight is normally retained by this aircraft while operating in that area.

Definition Source

ICAO (2001) FACILITIES AND SERVICE IMPLEMENTATION DOCUMENT AFRICA-INDIAN OCEAN REGION VOLUME II - FASID, First Edition, ABBREVIATIONS AND GLOSSARY OF TERMS

Note

Plot

Link	Semantic Value
Term	plot
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	primary surveillance radar (PSR) secondary surveillance radar (SSR)
Broader term
Narrower term	false plot

Abbreviation

Definition

A target report resulting from digital integration of the received echoes (PSR) or replies (SSR) inside the antenna beamwidth. The PSR report contains range and bearing information whereas the SSR report contains in addition Mode 3/A identity code and the Mode C decoded altimeter height value.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Plot combiner

Link	Semantic Value
Term	plot combiner
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	primary surveillance radar (PSR) secondary surveillance radar (SSR)
Broader term	plot
Narrower term

Abbreviation

Definition

A signal processing device for the combination of PSR and SSR data ascertained as having originated from the same target (aircraft). Targets failing to meet pre-defined combination criteria will be output as "PSR only" or "SSR only" plots in place of "combined plots".

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Plot extractor

Link	Semantic Value
Term	plot extractor
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	plot filter primary surveillance radar (PSR) secondary surveillance radar (SSR)
Broader term	plot
Narrower term

Abbreviation

Definition

Signal processing equipment which converts PSR or SSR video into an output data message suitable for transmission through a data transmission medium or possibly to further data processing equipment. (See “Plot filter”.)

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Plot filter

Link	Semantic Value
Term	plot filter
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	plot
Narrower term

Abbreviation

Definition

Signal processing equipment which filters out radar plot data positively identified as stationary by a rotation scan-to-scan correlation process.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Plot resolution

Link	Semantic Value
Term	plot resolution
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	plot
Narrower term

Abbreviation

Definition

A separation in range and azimuth between two plots, for which the quality of the information of one plot is not affected by the presence of the other plot.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Plot run length

Link	Semantic Value
Term	plot run length
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	plot
Narrower term

Abbreviation

Definition

The number of azimuth count pulses between the first and last detection of a plot presence in a sliding window plot extractor (see "Delta theta").

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Polar diagrams

Link	Semantic Value
Term	polar diagrams
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

Horizontal or vertical radiation patterns for a radar antenna whereby the relative gain is plotted as a function of the relative azimuth (horizontal polar diagram) or as a function of the relative elevation angle (vertical polar diagram). Polar diagrams for LVA antennas are measured separately on uplink and downlink with respect to the main beam axis.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Polarisation

Link	Semantic Value
Term	polarisation
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

Direction of the electrical field vector of radiated radar energy with respect to a plane tangential to the earth (horizontal, vertical, left-hand circular, right-hand circular, elliptical, etc.).

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Polished plots

Link	Semantic Value
Term	polished plots
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	plot
Narrower term

Abbreviation

Definition

Target reports at the output of the plot filter which rejects false targets coming from fruit, reflections, etc. Alternatively they are called filtered plots.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Precision Approach Radar

Link	Semantic Value
Term	Precision Approach Radar
Status
Mandatory for
Contexts	EAEA
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

PAR

Definition

Primary radar equipment used to determine the position of an aircraft during final approach, in terms of lateral and vertical deviations relative to a nominal approach path, and in range relative to touchdown.

Definition Source

Aeronautical Information Feature Data Dictionary (AIFDD)

Ref. ICAO, Official definition, ANNEX 10/I Aeronautical Telecommunications — Radio Navigation Aids

Note

Primary surveillance radar

Link	Semantic Value
Term	primary surveillance radar
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

PSR

Definition

1. A surveillance radar system which uses reflected radio signals.

2. A radar which detects presence of a target based on reflected radar energy from that target.

Definition Source

1. ICAO, Official definition, PANS-ATM Procedures for Air Navigation Services — Air Traffic Management [Doc 4444] 2001, 14th ed., Chap. 1

2. EUROCONTROL (1997) doc. "Radar Sensor Performance Analysis" SUR.ET1.ST03.1000-STD-01-01 [16]

Note

Pulse Repetition Frequency

Link	Semantic Value
Term	Pulse Repetition Frequency
Status
Mandatory for
Contexts
Categories
Synonyms	pulse recurrence frequency
Related entries	Stagger
Broader term
Narrower term

Abbreviation

PRF

Definition

An average number of pulses/interrogations per second transmitted by the radar (see “Stagger”). Also known as pulse recurrence frequency.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Pulse position modulation

Link	Semantic Value
Term	pulse position modulation
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Mode S
Broader term
Narrower term

Abbreviation

PPM

Definition

Modulation technique used for Mode S replies where a pulse transmitted in the first half of the bit position interval represents a binary ONE, whereas a pulse transmitted in the second half represents a binary ZERO.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Pulse train

Link	Semantic Value
Term	pulse train
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A sequence of framing and information pulses in the coded SSR reply.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Quick Reaction Codes

Link	Semantic Value
Term	Quick Reaction Codes
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Centralised SSR Code Assignment and Management System (CCAMS)
Broader term
Narrower term

Abbreviation

QRC

Definition

A limited amount of Omni directional SSR codes made available by the CCAMS Office on request in case of a single ATS unit failure.

Definition Source

EUROCONTROL, CCAMS Contingency Plan Ed 1.0

Note

RED Code

Link	Semantic Value
Term	RED Code
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Centralised SSR Code Assignment and Management System (CCAMS)
Broader term
Narrower term

Abbreviation

Definition

a pre-defined and agreed list of SSR codes that will be made available after declaration of CCAMS contingency level RED in order to allow their allocation to ATS Units for assignment according to a predefined scheme. The RED codes are described in the CCAMS Contingency Plan.

Definition Source

EUROCONTROL, CCAMS Contingeny plan Ed 1.0

Note

Radar Cross Section

Link	Semantic Value
Term	Radar Cross Section
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

RCS

Definition

The area intercepting that amount of power which, when scattered equally in all directions, produces an echo at the radar equal to that from the target.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Radar Data Processing System

Link	Semantic Value
Term	Radar Data Processing System
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

RDPS

Definition

A sub-system of an ATC centre which processes the incoming radar data (from one or more radar data sources) and prepares it for display.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Radial

Link	Semantic Value
Term	radial
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Lead Radial
Broader term
Narrower term

Abbreviation

Definition

1. A straight line of constant azimuth from the radar sensor site. A radial test flight would follow such a line.

2. A magnetic bearing extending from a VOR navigation facility.

Definition Source

1. EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

2.ICAO (2006) Terminology, Reference and Documenation database

Note

Receiver Side-Lobe Suppression

Link	Semantic Value
Term	Receiver Side-Lobe Suppression
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	side lobes
Broader term
Narrower term

Abbreviation

RSLS

Definition

A method, using two (or more) receivers to suppress aircraft replies which have been received via side lobes of the main beam of the antenna.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Reflections

Link	Semantic Value
Term	reflections
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	primary surveillance radar (PSR) secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

Unwanted signals (PSR or SSR) in the uplink and/or downlink paths resulting in erroneous replies entering the data processing system. Typical reflectors are ground obstructions such as aircraft hangars, buildings, towers and adjacent hills or mountains.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Reply

Link	Semantic Value
Term	reply
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

The pulse train received at a SSR ground station as a result of successful SSR interrogation.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Required Surveillance Performance

Link	Semantic Value
Term	Required Surveillance Performance
Status
Mandatory for
Contexts	SESAR
Categories
Synonyms
Related entries	required navigation performance
Broader term
Narrower term

Abbreviation

RSP

Definition

the set of system performance parameters that are required for a surveillance system to support a surveillance application.

Definition Source

ICAO (2002), doc. SCRSP/WG-A, WP A/4-140, SURVEILLANCE AND CONFLICT RESOLUTION SYSTEMS PANEL, AIRBORNE SURVEILLANCE AND CONFLICT RESOLUTION SYSTEMS, WORKING GROUP A, 4th Meeting, Langen, November 2002, Agenda item 4 a. RSP for airborne surveillance, Framework for the development of RSP

Note

Lexicon Release

Lexicon Release 2015.2

Resolution

Link	Semantic Value
Term	resolution
Status
Mandatory for
Contexts
Categories	Surveillance AIS
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

1. (surveillance) Ability of a system to distinguish between two or more targets in close proximity to each other both in range and bearing (azimuth).

2. (AIS) A number of units or digits to which a measured or calculated value is expressed and used.

Definition Source

1. ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

2. ICAO (2010) Official definition, ANNEX 15 Aeronautical Information Services

Note

Resolution advisory

Link	Semantic Value
Term	resolution advisory
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

RA

Definition

An indication given to the flight crew recommending:

a) a manoeuvre intended to provide separation from all threats; or

b) a manoeuvre restriction intended to maintain existing separation.

Definition Source

ICAO (2007) Annex 10, Aeronautical Telecommunications, Volume IV (Surveillance and Collision Avoidance Systems)

Note

Ring-around

Link	Semantic Value
Term	ring-around
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The continuous reception of aircraft replies to interrogations by the side lobes of the ground antenna. This normally occurs only at short ranges and high elevation angles, usually due to the nonexistence of a side-lobe suppression mechanism or the improper functioning of this mechanism at either the interrogator or the transponder side.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Round reliability

Link	Semantic Value
Term	round reliability
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

A probability of receipt of a correct reply, resulting from either an SSR interrogation or a PSR transmission.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

SSR Mode A

Link	Semantic Value
Term	SSR Mode A
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Garbled mode A SSR Mode C SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

The identification of an aircraft as reported by its SSR transponder. This 12-bits code is manually set by the pilot on request of ATC. This code is often called the 'squawk identification' and is usually represented as 4 octal digits (e.g. 0627). Special codes are reserved for emergency situations (7500 = hijack, 7600 = radio failure, 7700 = general emergency). (often abbreviated as: SSR code).

Definition Source

EUROCONTROL, SASS-C Glossary

Note

SSR Mode C

Link	Semantic Value
Term	SSR Mode C
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode A SSR Mode S
Broader term
Narrower term

Abbreviation

Definition

The altitude of an aircraft as reported by its SSR transponder expressed in flight levels. Possible values are between FL 12 and FL 1267. (Pronounced Mode Charlie).

Definition Source

EUROCONTROL SASS-C Glossary

Note

SSR Mode S

Link	Semantic Value
Term	SSR Mode S
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode A SSR Mode C
Broader term
Narrower term

Abbreviation

Definition

An enhanced mode of SSR which permits the interrogation of SSR equipped aircraft and addressed interrogations with two way data exchange for suitably equipped aircraft.

Definition Source

EUROCONTROL SASS-C Glossary

Note

SSR Mode S address

Link	Semantic Value
Term	SSR Mode S address
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	SSR Mode S aircraft address
Broader term
Narrower term

Abbreviation

Definition

The SSR Mode S address shall be one of 16 777 214 twenty-four-bit aircraft addresses allocated by ICAO to the State of Registry or common mark registering authority and assigned as prescribed in 3.1.2.4.1.2.3.1.1. in the Appendix to Chapter 9, Part 1, Volume III, Annex 10.

Definition Source

ICAO, Annex 10, Aeronautical Telecommunications, Volume IV

Note

SSR code

Link	Semantic Value
Term	SSR code
Status
Mandatory for
Contexts
Categories
Synonyms	code (SSR)
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

1. code (SSR) "The number assigned to a particular multiple pulse reply signal transmitted by a transponder in Mode A or Mode C."

2. SSR code "A four-digit octal number received from the aircraft transponder when it is interrogated by a secondary surveillance radar (SSR)"

Definition Source

1. ICAO, Official definition, PANS-ATM Procedures for Air Navigation Services — Air Traffic Management [Doc 4444] 2001, 14th ed. (Amdt 3, 29/06/2004)

2. Transport Canada (2010) Glossary for Pilots and Air Traffic Services Personnel, [17]

Note

Second-Time Around Targets

Link	Semantic Value
Term	Second-Time Around Targets
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Pulse Repetition Frequency (PRF)
Broader term
Narrower term

Abbreviation

STAT

Definition

Target returns from ranges beyond that associated with a basic PRF interval.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Secondary surveillance radar

Link	Semantic Value
Term	secondary surveillance radar
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Air Traffic Control Radar Beacon System
Broader term
Narrower term

Abbreviation

SSR

Definition

A surveillance radar system which uses transmitters/receivers (interrogators) and transponders.

Definition Source

ICAO Official definition, ANNEX 10/IV Aeronautical Telecommunications — Surveillance Radar and Collision Avoidance Systems

Note

Secondary surveillance radar (SSR), which had its beginnings in wartime Identification Friend or Foe (IFF) systems, transmits pulses of energy which trigger a response from an airborne transponder, with range and bearing obtained in the same way as primary radar. (source: ICAO, "APOSI Airports International" 1993, April, p. 28 [TF-ATM])

Secondary surveillance radar transponder

Link	Semantic Value
Term	Secondary surveillance radar transponder
Status
Mandatory for
Contexts
Categories
Synonyms	SSR transponder
Related entries	secondary surveillance radar (SSR)
Broader term	transponder
Narrower term

Abbreviation

Definition

A unit which transmits a response signal on receiving an SSR interrogation. The term is a derivative of the words transmitter and responder.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Side lobes

Link	Semantic Value
Term	side lobes
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Side-lobe suppression
Broader term
Narrower term

Abbreviation

Definition

Lobes of the radiation pattern of an antenna, which are not part of the main or principal beam. Radar systems can have sufficient sensitivity via side lobes for successful detection of aircraft (particularly for SSR, but also for PSR). Special precautions are necessary to protect against these false plots.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Side-lobe suppression

Link	Semantic Value
Term	side-lobe suppression
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	interrogator side-lobe suppression secondary surveillance radar transponder
Broader term
Narrower term

Abbreviation

Definition

A mechanism in an SSR transponder activated by the transmission (radiation) of a control pulse (P2 or P5) of amplitude greater than the antenna side-lobe signals-in-space, which will enable the transponder to prevent itself from replying to the side-lobe interrogation signals.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Spurious plot

Link	Semantic Value
Term	spurious plot
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	secondary surveillance radar (SSR)
Broader term
Narrower term

Abbreviation

Definition

Unwanted radar plot not corresponding directly with an aircraft position (generally applied for SSR).

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Squitter

Link	Semantic Value
Term	squitter
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

The spontaneous periodic transmission by a Mode S transponder (nominally once per second) of a specified format to permit passive acquisition by Mode S interrogators with broad antenna beams (e.g. ACAS).

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Stagger

Link	Semantic Value
Term	Stagger
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	Pulse Repetition Frequency
Broader term
Narrower term

Abbreviation

Definition

Deliberate, controlled variation of the pulse repetition frequency of the SSR to prevent aircraft plots due to second-time-around replies.

Definition Source

ICAO (2004), doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Sum pattern

Link	Semantic Value
Term	sum pattern
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	difference pattern
Broader term
Narrower term

Abbreviation

Definition

Normal radiation pattern for the main directional beam of an antenna. Contrasts with the “difference pattern”, where parts of the radiating elements of the antenna are switched in anti-phase to produce signals proportional to the amount by which the source is off the boresight of the sum pattern.

Definition Source

ICAO (2004) doc. 9684 Manual of the Secondary Surveillance Radar (SSR) Systems

Note

Surveillance radar

Link	Semantic Value
Term	'
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term	primary surveillance radar (PSR) secondary surveillance radar (SSR)

Abbreviation

Definition

Radar equipment used to determine the position of an aircraft in range and azimuth.

Definition Source

ICAO (2005) Official definition, ANNEX 10/IV Aeronautical Telecommunications — Surveillance Radar and Collision Avoidance Systems

Note

Surveillance services

Link	Semantic Value
Term	surveillance services
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

SUR

Definition

facilities and services used to determine the respective positions of aircraft to allow safe separation.

Definition Source

EUROCONTROL Specification for Economic Information Disclosure, Edition 2.6, Edition date: 31.12.2008, Reference nr: EUROCONTROL-SPEC-0117

Note

System track

Link	Semantic Value
Term	system track
Status
Mandatory for
Contexts
Categories
Synonyms	multi track
Related entries	local track
Broader term
Narrower term

Abbreviation

Definition

an aircraft trajectory calculated from plots coming form several radar sites or by combining several mono tracks

Definition Source

EUROPEAN COMMUNITY (2000) COMPETITIVE AND SUSTAINABLE GROWTH PROGRAMME, INTENT WP 3 Implementation Roadmap, p. 27 (tracking) [18]

Note

Systematic errors

Link	Semantic Value
Term	systematic errors
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	residual errors
Broader term
Narrower term

Abbreviation

Definition

"...the bias or fixed component of the radar error. In SASS-C this is modelled using 6 variables: the position, (U,V) of the radar, range, range gain, azimuth and time.

Definition Source

EUROCONTROL, SASS-C Glossary

Note

Target report

Link	Semantic Value
Term	target report
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	combined target report
Broader term
Narrower term

Abbreviation

Definition

A digital message which depending on the filtering function applied can be either polished / filtered plot or track.

Definition Source

EUROCONTROL (1997) doc. "Radar Sensor Performance Analysis" SUR.ET1.ST03.1000-STD-01-01 [19]

Note

Time difference of arrival

Link	Semantic Value
Term	time difference of arrival
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	multilateration system
Broader term
Narrower term

Abbreviation

TDOA

Definition

The difference in relative time that a transponder signal from the same aircraft (or ground vehicle) is received at different receivers.

Definition Source

ICAO (2010) ANNEX 10/IV Aeronautical Telecommunications — Surveillance Radar and Collision Avoidance Systems 2010, amdt 85

Note

Time stamp

Link	Semantic Value
Term	time stamp
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	time stamp error
Broader term
Narrower term

Abbreviation

Definition

The addition of the time information - in the relevant field - in the target report (plot or track).

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

In the ASTERIX ("All Purpose STructured Eurocontrol SuRveillance Information EXchange") the time information is coded in two octets with Least Significant Bit (LSB) equal to 1/128 seconds.

Time stamp error

Link	Semantic Value
Term	time stamp error
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term	time stamp
Narrower term

Abbreviation

Definition

the constant time difference between the time system used for plot detection time stamping and a common reference time.

Definition Source

EUROCONTROL (1997) "Radar Sensor Performance Analysis", doc. SUR.ET1.ST03.1000-STD-01-01

Note

Track

Link	Semantic Value
Term	track
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term

Abbreviation

Definition

1. A target report resulting from the correlation, by a special algorithm (tracking) of a succession of radar reported positions for one aircraft. The report normally contains smoothed position and speed vector information.

2. The locus of positions grouped over time which defines the path of an aircraft in flight as referenced to a desired coordinate system (e.g., slant range (range, azimuth), geographical or Cartesian (range-x, range-y, range-z)).

Definition Source

1. EUROCONTROL, SASS-C (Surveillance Analysis Support System for ATC-Centre) Glossary

2. U.S. Department of Transportation (2008) Federal Aviation Administration, Interface Control Document, Standard Terminal Automation Replacement System (STARS) To Airport Surface Detection Equipment – Model X (ASDE-X), NAS-IC-21053418-01D, Final

Note

Trailing edge

Link	Semantic Value
Term	trailing edge
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	leading edge
Broader term
Narrower term

Abbreviation

Definition

1. (Surveillance) "Outline of pulse as amplitude falls from peak to zero or minimum positive value."

2. (Aircraft) The rear edge of an airfoil.The trailing edge is normally thin and sharp. The ailerons are normally located on the trailing edge of the wing.

Definition Source

1. Jane's Aerospace Dictionary, 1988

2. NASA Quest [20]

Note

Transponder

Link	Semantic Value
Term	transponder
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries
Broader term
Narrower term	secondary surveillance radar transponder

Abbreviation

Definition

1. A receiver/transmitter which will generate a reply signal upon proper interrogation; the interrogation and reply being on different frequencies.

2. (AIM) The airborne radar beacon receiver/transmitter portion of the Air Traffic Control Radar Beacon System (ATCRBS) which automatically receives radio signals from interrogators on the ground, and selectively replies with a specific reply pulse or pulse group only to those interrogations being received on the mode to which it is set to respond.

Definition Source

1. ICAO (2006) Terminology, Reference & Documentation database

2. FAA (2010) Pilot/Controller Glossary [21]

Note

Wide area multilateration

Link	Semantic Value
Term	wide area multilateration
Status
Mandatory for
Contexts
Categories
Synonyms
Related entries	multilateration system
Broader term
Narrower term

Abbreviation

WAM

Definition

Multilateration systems that monitor aircraft in flight. (As distinct from surface surveillance)

Definition Source

National Aerospace Laboratory NLR (2005), NLR-CR-2004-472, Wide Area Multilateration, Report on EATMP TRS 131/04, Version 1.1

Note