Squitter (original) (raw)
Squitter refers to random pulses, pulse-pairs and other non-solicited messages used in various aviation radio systems' signal maintenance. Squitter pulses were originally, and are still, used in the DME/TACAN air navigation systems. Squitter pulses, because of their randomness and identical appearance to standard reply pulse-pairs, appear the same as unsolicited/unsynchronised replies to other interrogating aircraft.
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dbo:abstract | Squitter refers to random pulses, pulse-pairs and other non-solicited messages used in various aviation radio systems' signal maintenance. Squitter pulses were originally, and are still, used in the DME/TACAN air navigation systems. Squitter pulses, because of their randomness and identical appearance to standard reply pulse-pairs, appear the same as unsolicited/unsynchronised replies to other interrogating aircraft. Squitter was first used in the original IFF systems. These used a superregenerative receiver which greatly amplified input signals using positive feedback. If the gain was set too high, random radio noise like static would enter the amplifier and cause it to send out a signal, creating random signals. An automatic gain control system on subsequent models cured this problem. Primarily, squitter is used to maintain a regular signal from the ground beacon. In the TACAN system, signal strength variation due to rotation of the transmitting beam (amplitude modulation) determines the course bearing function. This function would be lost without a constant 2700-4800 pulse-pairs per second, carrier-like signal in cases of low or no interrogating aircraft. In the Mode S secondary surveillance radar system, the term is used to describe messages that are unsolicited downlink transmissions from an automatic dependent surveillance-broadcast (ADS-B) Mode S transponder system. Mode S transponders transmit acquisition squitter (unsolicited downlink transmissions) to permit passive acquisition by interrogators with broad antenna beams, where active acquisition may be hindered by all-call synchronous garble. Examples of such interrogators are an airborne collision avoidance system and an airport surface system. (en) |
dbo:wikiPageExternalLink | https://www.radartutorial.eu/13.ssr/!sr01.en.html http://www.collisionavoidance.org http://www.radartutorial.eu/index.en.html |
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dbo:wikiPageInterLanguageLink | dbpedia-de:Sekundärradar dbpedia-fi:Toisiotutka dbpedia-fr:Radar_secondaire dbpedia-no:Sekundærradar |
dbo:wikiPageLength | 2360 (xsd:nonNegativeInteger) |
dbo:wikiPageRevisionID | 1081363778 (xsd:integer) |
dbo:wikiPageWikiLink | dbr:Identification_friend_or_foe dbr:White_noise dbr:Distance_measuring_equipment dbr:Gain_(electronics) dbc:Radar dbr:Positive_feedback dbc:Air_traffic_control dbc:Avionics dbr:TACAN dbr:Automatic_gain_control dbr:Automatic_dependent_surveillance-broadcast dbr:Carrier_wave dbr:Secondary_surveillance_radar dbr:Traffic_collision_avoidance_system dbr:Transponder_(aeronautics) dbr:Superregenerative_receiver |
dbp:wikiPageUsesTemplate | dbt:Comm-stub dbt:Refimprove |
dct:subject | dbc:Radar dbc:Air_traffic_control dbc:Avionics |
gold:hypernym | dbr:Term |
rdfs:comment | Squitter refers to random pulses, pulse-pairs and other non-solicited messages used in various aviation radio systems' signal maintenance. Squitter pulses were originally, and are still, used in the DME/TACAN air navigation systems. Squitter pulses, because of their randomness and identical appearance to standard reply pulse-pairs, appear the same as unsolicited/unsynchronised replies to other interrogating aircraft. (en) |
rdfs:label | Squitter (en) |
owl:sameAs | freebase:Squitter wikidata:Squitter https://global.dbpedia.org/id/fqCy |
prov:wasDerivedFrom | wikipedia-en:Squitter?oldid=1081363778&ns=0 |
foaf:isPrimaryTopicOf | wikipedia-en:Squitter |
is dbo:wikiPageWikiLink of | dbr:Distance_measuring_equipment dbr:Automatic_Dependent_Surveillance–Broadcast dbr:Aviation_transponder_interrogation_modes dbr:Secondary_surveillance_radar dbr:IFF_Mark_II dbr:Traffic_information_service_–_broadcast |
is foaf:primaryTopic of | wikipedia-en:Squitter |