Transponders (Mode-2, Mode-C, Mode-S) transmit an aircrafts heading, speed, altitude, and ident. This info is requested by the ground based Beacon Interrogator commonly referred to as the Secondary Radar (not really a radar).
Primary Radar (ASR-8/9/ or 11) paint a target with a 1 microsecond pulse and awaits the return of the signal. A primary Radar *** DOES NOT *** require a transponder to track a target. Primary radars are often paired with Secondary Radars -aka- Transponder Beacon Interrogators. The ASR-9/ and 11 are also Doppler Radars, which use phase detection for higher resolution, which then allows Air Traffic to decrease aircraft separation. They see anything moving to include six levels of weather.
CT #4 response here:
http://answers.yahoo.com/question/index?qid=20070911170250AAmuyft&r=w
2007-09-11
15:50:24
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11 answers
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asked by
Chi Guy
5