Collimatrix

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  1. Maximum angular resolution is a function of beam width. Beam width is a function of antenna size and operating wavelength. An AESA might be able to wring a slightly smaller beam width out of a given antenna size and a given wavelength, but it is still subject to these same limitations. It's fundamental physics; you see similar-looking equations if you look into the maximum focal range of laser weapons. L band is an order of magnitude longer wavelength than X band. Wing antennas are narrower than nose-mounted radars. This supposed "wing mounted L band AESA radar" is going to have less than a tenth the resolution of the nose radar. Computer signal processing do a much better job of finding useful signals. A more capable computer can find information that a weaker computer would have to throw away as noise. But there are information theoretic limits. Computers cannot create information that they weren't given in the first place. Computers aren't magical. They cannot improve the resolution of a grainy photo to show the face of the killer reflected in a raindrop. If a radar has a small antenna relative to its operating wavelength then its beam will be quite wide. If there are two targets within that beam width at the same distance moving at the same speed then there is no possible way that the computer will be able to tell whether it's one target or two. There simply is not enough information for the computer to dig through to find out what is going on. Likewise, if a radar has a wide beam and it's engaging a moving target, it is going to have a hard time figuring out where exactly in this wide beam the returns are coming from. It can move the beam around until it stops getting return signal, but the edge of a radar beam isn't a clean and abrupt end, and if the target is moving it won't be able to do this quickly enough to get a precise location anyway. These are fundamental problems with the amount of information that the antenna can provide the computer. The computer won't be able to fill in the blanks.
  2. It's an Actively Electronically Scanned Array (AESA), but that does not mean it is a radar. AESA is just a type of antenna, it doesn't necessarily mean it's a radar antenna. It could be a transmit-only antenna, or a receive-only antenna. It can't be a radar. Or if it were, it would be the world's most singularly useless radar. This isn't a matter of experience or design finesse, this is a matter of fundamental radar antenna physics. That is not a large enough antenna relative to the wavelength it's operating in. It is almost certainly an IFF system, but one that uses an AESA. The way IFF works is that the aircraft with the IFF system gets pinged by a radar, and the radar sends a coded interrogation signal. The aircraft that receives this signal sends back a coded response, which identifies it to friendly forces. The problem with this for a stealthy jet is that the IFF system is broadcasting radio waves, which is decidedly un-stealthy and could allow any radar with a passive seeker mode to get a bearing fix on the aircraft. The solution Sukhoi is using here is an AESA IFF system. Instead of a regular antenna, the response IFF signals are transmitted through the AESA, which allows it to confine the signal to a very narrow beam. AESA has extremely high gain and very small sidelobes, so it can make the IFF beam much narrower than a conventional antenna. That makes it much less likely that an enemy eavesdropper will detect these signals and use them to locate the PAK-FA.
  3. Figure from an experiment, showing how ERA is drastically less effective when it is not oblique relative to the threat:
  4. The automatic grenade launcher is a QLZ-04.
  5. These are valve-timing gears from the Bristol Hercules radial engine. This engine powered a number of mid-WWII British aircraft including the Beaufighter and Stirling. The Hercules used sleeve valves, which reciprocate independently of the pistons and thus require this giant mess of drive gears. In the late 1930s there were a number of fairly convincing papers that predicted that aircraft engines would plateau in power density unless they switched to sleeve valves. In actuality, conventional poppet valves were greatly improved and by the time aircraft sleeve valve engines were mature they had only modest power advantages over poppet-valve designs.
  6. Yes, they are shock absorbers and the actual torsion bars are underneath. This is easy to tell; not all the road wheel stations have them. But they have to be mounted to something rigid, and the hull side composite armor is not rigid enough. They also show the thickness of the hull side composite armor because of the cutout to house them.
  7. The BBC picked it up.
  8. What are you talking about? TF2? You mean the hat simulator?
  9. It's different. Overwatch is a shooter first with a hint of MOBA flavor. First person MOBAs are a pretty dubious idea.
  10. Meanwhile, attempts to construct a good post-mortem of the Clinton campaign have... run into complications. Unless this is all fake hype deliberately generated to improve sales of the book, in which case, very clever.
  11. Something just occurred to me about the circular runways. The entire point is that the pilot can approach the circle at any tangent and thereby avoid having to land into a crosswind, right? But the pictures show the circle being so small that the banking angle significantly affects the wingtip clearance. My recollection is that 747s do not slow down quickly. So, fairly quickly, as the plane goes around in a circle, it's going to change heading and be in a crosswind.
  12. Right now I think there are exactly three sorts of games you don't want to make: MOBA Overwatch-clone MMORPG
  13. Did not photoshop The Donald into a maid outfit. 0/10
  14. Not providing government handouts to help people destroy themselves is simply un-American.
  15. As long as the police are setting aside areas for political extremists to fight each other (props on selecting Berkley), wouldn't it make more sense to supply both sides with weapons to ensure some degree of fairness?