Page 128 of 128 FirstFirst ... 119120121122123124125126127128
Results 1,906 to 1,910 of 1910

Thread: What is up with the F-35? Part II

  1. #1906
    Regular
    Join Date
    23 Oct 13
    Posts
    88
    "At close range or against targets using Jammers it is capable of narrowband interleaved search and track, which provides precise range and velocity that can then be used to shoot a missile without the need of the APG-81, allowing a 360 degree sphere of targeting other aircraft."

    This is a little hard to parse. I still took that to mean that the system is operating in a passive mode and that if two conditions are met - very close range (and presumably quick bearing changes to average out ambiguities) or active jamming (presumably a more powerful signal? Or else potentially using a false target jamming mode against it self for localization? Hard to say). To me that still implies a passive track, although I still don't see how you could establish range without target speed. Maybe the speed can be extrapolated from doppler shift of the carrier wave plus bearing change? I'd hate to have to make THAT calculation by hand.

    That said, that wouldn't exclude an active mode that created false targets (of F-35ish size) or other more specific push off/pull off deceptive modes, though in the case of the latter I'd expect the towed decoy to be the primary emitter as it implies a missile has a lock.

  2. #1907
    Senior Contributor SteveDaPirate's Avatar
    Join Date
    08 Aug 13
    Location
    Kansas City, United States
    Posts
    1,427
    Quote Originally Posted by Josh View Post
    "At close range or against targets using Jammers it is capable of narrowband interleaved search and track, which provides precise range and velocity that can then be used to shoot a missile without the need of the APG-81, allowing a 360 degree sphere of targeting other aircraft."

    This is a little hard to parse. I still took that to mean that the system is operating in a passive mode and that if two conditions are met - very close range (and presumably quick bearing changes to average out ambiguities) or active jamming (presumably a more powerful signal? Or else potentially using a false target jamming mode against it self for localization? Hard to say). To me that still implies a passive track, although I still don't see how you could establish range without target speed. Maybe the speed can be extrapolated from doppler shift of the carrier wave plus bearing change? I'd hate to have to make THAT calculation by hand.

    That said, that wouldn't exclude an active mode that created false targets (of F-35ish size) or other more specific push off/pull off deceptive modes, though in the case of the latter I'd expect the towed decoy to be the primary emitter as it implies a missile has a lock.
    I interpreted "search and track" to mean actively radiating (at low power) to find and target objects at close range in areas the APG-81 doesn't cover. In which case radiating other signals for ECM purposes shouldn't present a challenge.

    If it's referring to a passive function that picks up and localizes emission sources such as hostile fighter radar, that wouldn't be a close range function. Detection and localization of hostile radar emissions looking for the F-35 should have a much greater effective range than even the APG-81's ability to find that target due to not requiring a return bounce. I would think an actively radiating target could be engaged at significant while the F-35 stays entirely passive by using a data link to guide the AIM-120 like an anti-radiation missile.

    I'm just not sure where the "close range" stipulation would come into play if the system is entirely passive.
    Last edited by SteveDaPirate; Yesterday at 18:20.

  3. #1908
    Regular
    Join Date
    23 Oct 13
    Posts
    88
    Clearly the system can generate bearings of an active source at long range. What is interesting is that it credits it with being able to establish range in one of two conditions: close range or active jammer. The key phrase seems to be 'narrowband interleaved search and track', which honestly I don't know the meaning of. A google search did turn up a article reference on F-16.net:

    "High-priority emitters -- such as fighter aircraft at close range -- can be tracked in real time by the ALR-94. In this mode, called narrowband interleaved search and track (NBILST), the radar is used only to provide precise range and velocity data to set up a missile attack. If a hostile aircraft is injudicious in its use of radar, the ALR-94 may provide nearly all the information necessary to launch an AIM-120 AMRAAM air-to-air missile (AAM) and guide it to impact, making it virtually an anti-radiation AAM."

    http://www.f-16.net/forum/viewtopic.php?t=9268

    So it looks like for the crucial range component something would have to be active...but since the bearing and azimuth have been determined, the frequency of the range measurement doesn't matter: you aren't attempting to localize the target, just get the ping return time to determine range. So I think your assessment that the antennas are low power emitters that could ping a target at close range probably is accurate from the open source descriptions I've seen.

    The other stipulation, that the aircraft is jamming, presumes long range detection is possible if there is an active ECM. That part I definitely don't understand - I would think ECM like active radar could be tracked by bearing but I don't see how you would get any range component without the fighter using its radar.

  4. #1909
    Senior Contributor SteveDaPirate's Avatar
    Join Date
    08 Aug 13
    Location
    Kansas City, United States
    Posts
    1,427
    It appears the Dutch are considering upping their F-35 buy from 37 to 67 jets.

    https://twitter.com/Rotorfocus/statu...40058118180866

    https://www.telegraaf.nl/nieuws/2573...-aanschaf-f-35

  5. #1910
    Global Moderator
    Comrade Commissar
    TopHatter's Avatar
    Join Date
    03 Sep 03
    Posts
    16,272
    It appears the Dutch are considering upping their F-35 buy from 37 to 67 jets.
    But why? It's a total failure and will never amount to anything....

    Oh wait, I forgot, I'm not a paid Russian troll. Never mind! :-)
    Far better it is to dare mighty things, than to take rank with those poor, timid spirits who know neither victory nor defeat ~ Theodore Roosevelt

Thread Information

Users Browsing this Thread

There are currently 26 users browsing this thread. (0 members and 26 guests)

Similar Threads

  1. Sig P250, Part 2
    By GraniteForge in forum Small Arms and Personal Weapons
    Replies: 7
    Last Post: 26 Nov 08,, 00:04
  2. What part do you disagree with?
    By Roosveltrepub in forum American Politics & Economy
    Replies: 6
    Last Post: 22 Apr 08,, 16:52
  3. Who wants to be a part?
    By joey2 in forum International Politics
    Replies: 4
    Last Post: 22 Nov 06,, 00:31
  4. I did my part
    By bren in forum Military Aviation
    Replies: 0
    Last Post: 08 Nov 06,, 10:49

Share this thread with friends:

Share this thread with friends:

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •