Indian --> Identification Friend-or-Foe

[Badar]

Hi,<P>Salman, <P>1. What do number of codes signify?<BR>2. What is stability?<BR>3. Janes also says that the Type 405A uses Mode C altitude coding. Any idea what that is?<P>

[Atul]

Salman,<P>>> 405A is a solid state transponder providing automatic replies to ground or airborne interrogators operating on the IFF Mark X system >><P>>> More than 1800 type 405As have been installed on fighter a/c and helicopters of IAF, IA, IN and coastal guard >><P>Could you please answer my following queries:<P>1) I understand from above that for airborne interrogation the aircraft must have IFF Mark X system. If yes, then any idea if IAF,IA,IN a/c have the same for airborne interrogation( since the post mentions installation of transponders 405As ).<P>2) Can these tranponders on a/c be dynamically programmable to respond with different signals changing from sortie to sortie? If yes, do the number of codes have anything to do with it? <P>3) Since the IFF/SSR spec does not have number of codes in it, does it mean that on interrogation the IFF/SSR always transmits the same signal.<P>Thanks<P>atul

[Madhusudhan]

1. What do number of codes signify?<BR>all Civilian aircraft also have transponders with 4096 codes. When you contact Air Traffic Control, they will assign you a transponder code and you "sqawk" it in your transponder.. This is the code you will be identified by in ATC Radar.<P>3. Janes also says that the Type 405A uses Mode C altitude coding. Any idea what that is<BR>All aircraft flying into controlled airspace in the US (Class C, Class B, Class A, etc) are required to have a Mode C altitude encoding transponder. This means when the transponder sends signals, it also sends the altitude of you plane along with it and this appears on ATC radar.<BR>

[vverma]

Does anybody know what GUARD and BITE stand for? These are also acronyms for radar comm channels like IFF. Appreciate any answers. <BR>