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Bharatheeyan

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Viewing 9 posts - 61 through 69 (of 69 total)
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  • in reply to: Most annoying travel problem… #545664
    Bharatheeyan
    Participant

    Nose all stuffed up and the pressure changes popping the eardrum. Happened on my very first trip abroad.

    in reply to: IAF News & Discussions #2596032
    Bharatheeyan
    Participant

    But MiG-35 is the least finished plane. The only promised thing in existence is the TVC engine. I personally like the plane as it is specd, but I am not confident of it being built, qualified and inducted in the expected time frame.

    in reply to: AESA Vs Phased Array #2596036
    Bharatheeyan
    Participant

    With the AESA with individual signal generators, the transmit side will work great, but what do you do with the received signal? Those individual signals need to be combined at the right phase relationships to get the proper received signal. The only way to achieve it is to digitize the output of the individual receivers and to combine the outputs by using Digital Signal Processing.

    The output of the individual rx modules have lower amplitude. If you combine the outputs through a phase shifter (as in PESA), it will result in a higher amplitude combined signal, which can be processed digitally. Processing a lower amplitude signal have less Signal to Noise ratio than processing a higher amplitude signal.

    in reply to: AESA Vs Phased Array #2596609
    Bharatheeyan
    Participant

    There are three related radar technologies that have confusing names.

    Phased Array Antenna means the shaping or focussing of the beam is done by feeding an array of emitters with a single high power feed at appropriate phase relationship. Here the phase relationship is fixed, so the beam points at a fixed direction with respect to the array. The beam is scanned by mecahnically moving the whole array

    Electronically Scanned Array means the phase relationship is electronically varied to scan the beam without physically moving the antenna array.

    Passive Electronically Scanned Array (PESA / PFAR in Russian) is the phase is changed passively using phase shifters and switches. Typically a single high power source is used which is passed through the phase shifters and fed to the antenna array.

    There are two types of Active Electronically Scanned Array (AFAIK). One type is similar to PESA, but there are amplifiers in the individual antenna modules, so the phase shifting can be done at low power, resulting in better efficiency. AFAIK, the russian systems in development follow this route. I would be glad to be proven wrong there 🙂

    The other AESA have individual modules generating its own signal. This system has a number of advantages over the others, including high efficiency and high agility of the beam. On the other hand this system arguably have lower S/N ratio.

    in reply to: It's alright I'll push myself back… #553229
    Bharatheeyan
    Participant

    The “Super-80″s of AA did it every time when I took a multi hop trip all around USA.

    in reply to: Jet buys Sahara #566471
    Bharatheeyan
    Participant

    Some media says no LCC. Some say everything will be merged under a single brand.

    in reply to: Jet buys Sahara #567163
    Bharatheeyan
    Participant
    in reply to: Jet buys Sahara #576029
    Bharatheeyan
    Participant
    in reply to: Sleepy Norwegian on plane – funny! #611091
    Bharatheeyan
    Participant

    A few years ago a lady on an AI flight slept through two landings and returned to origin. Left cochin, landed at two places in gulf and came back.

Viewing 9 posts - 61 through 69 (of 69 total)