The system has not performed "a lock on the target", at least not in the way that the language leads you to believe. The tool is making a prediction, that within a certain level of confidence, and given the present parameters, that firing the missile will result in the neutralization of the target.
There's growing number of ways, both active and passive, that targets can be tracked or future positions predicted. One of the answers on that page hints at this, the other answer is misleading and often not how it's done in many modern systems.
The radar and weapon control systems are "locked on" to from the aircraft's perspective - I don't really understand what you're talking about...
A particular target has been identified, it is being tracked (maybe at the expense of scanning for other targets if its an older system, probably with track-while-scan otherwise), and based on this updates are being sent to the missile in order to control its initial trajectory when it gets launched to point it in the correct direction.
Related anecdote - I worked with a coder a while back who was a naval aviator before he went back to school, flying carrier-based transports. I asked him once about whether he would have wanted to fly fighters instead, and he said that just flying transports was already a huge amount of work, as far as flight plans, training, practice, and such. Flying fighters apparently involved doing all of that same work, plus a bunch more for weapons, tactics, etc, so those guys never had any free time. Apparently, flying fighters wasn't nearly as fun as it sounds.
On the other hand, when you're the engineer maintaining the flight sims for the pilots, boy oh boy can you have fun in those machines :) I've logged over 100 hours on the F-18, and 20 for the F-111. Never got to experience those long high G turns though...
believe me, flying fighters really is as much fun as it sounds. It is more work than the transport guys, but you get out what you put in. its all worth it coming in for a 450 knot overhead at 600', pulling six g's in the break, then catching the three-wire aboard the carrier.
To remember that there are people that can and do pilot those jets regularly, before coming home to their family, gives me a kind of feeling of vertigo and envy, that my life (and the other peasants around me) is flat, onedimensional, boring and meaningless.
> Apparently, flying fighters wasn't nearly as fun as it sounds.
Hm. I figure the glory you get from being a fighter pilot is one of the perks, so they might as well milk that for all it's worth.
My point is that it's interesting to note the professions that seem more glorious than they actually are, and beware those who sell themselves or the job based on that glory: it's an illusion.
So why don't they include two radars, one for sweeps and one for tracking? I know, I know, weight, power, etc. At the same time, isn't that the obvious answer?
Note how the radar's processing units and dish take up the entirety of the aircraft's nose and how large the system is compared to the technician working on it. There simply isn't enough space to add another radar.
Nor would it make sense to split that into two smaller radars, as the size of the dish and processing units is strongly linked to its power and range. That's one reason larger aircraft like the F-15, F-14 and Su-27 have longer-ranged and more powerful radars than smaller fighter aircraft.
Rather than having a mechanically-slaved reflective dish, an AESA radar has hundreds of Transmit/Receive Modules (TRMs) each capable of acting like a tiny radar dish by transmitting or receiving on its own frequency and being steered its own direction.
So now, rather than having the radar dish jump between track and scan at rapid intervals, the system can just dedicate a few hundred of the AESA TRMs to tracking one or more targets while letting the remainder continue sweeping the skies. There's no limitation on azimuth because each TRM can be individually steered.
So in short, the answer is that the latest fighter aircraft don't have two radars, they have hundreds or thousands of tiny radars that can work together in a whole bunch of useful combinations.
Edit: Replaced initial image with a Wiki Commons link that doesn't have linking issues.
It is important to note that the antennae in a phased array (TRMs) cannot be "steered" individually: it is the electronics that creates a beam by timing the transmit and receive signals to a number of antennae. It's similar to the way an array of atoms creates a pattern of beams in x-ray crystallography, if that makes it clearer.
This does also mean that the whole array can be pointed in multiple directions at once: The only limitation is the number of phase shifters coming off of each antenna (if the signals are directly sampled and then the beam forming is done in software you are then only limited by your processing power. I'm not sure if this is currently possible in radar but I've seen it done for sonar).
Yes, you're right, I shouldn't have simplified it that much. Upvoted you because your comment deserves more attention.
The steering uses amplitude and phase shifting to create beams through constructive or destructive interference. All very fascinating stuff, and it allows for additional uses like jamming and directional communications links.
as other commenter said ESA radars do great simultaneously scanning and tracking, with modern radars - more than 1 target simultaneously. The 2nd radar may be employed for the rear sphere like in that rear "stinger" http://www.airforceworld.com/bomber/eng/su34-fighter-bomber-...
How is it an obvious solution if it is not practical?
The electronically-scanned radars mentioned in the second answer can easily divide their time between the tasks (no mechanically-constrained dish to sweep) but there is definitely no space for two radar systems in the nose of a fighter.
Hmmm, I was kind of hoping for an explanation of how the control system determines how to modify the highly directional antenna's orientation to continue to maximally "illuminate" the target once it's been selected from a general scan.
Can anyone describe the solution to this?
Example idea: Once selected for "lock," the antenna scans in small circles and migrates its central point toward the point on the scanned circle that provides the strongest return, allowing for variation due to noise sources.
There is a book on it[1]. But suffice it to say that the radar is computing an "exit vector" when the target it moving away from center and applying a correction to the pointer. I built a similar system with LEDs when building a tracking system for two moving robots. In my case I used a parabolic dish (a solar cigarette lighter) and a line of LEDs (bar graph display) as detectors rather than lights. Since the target robot and the pursuing robot had their beacon and search dish in the same plane I could reduce the problem to a managable bit of 2D geometry. As the signal went off axis you could turn the robot to re-align by applying the opposite rotation.
Are you asking if the antenna gets moved to illuminate the target once acquired? I apologize if I misunderstood. If that's the case, the antenna is a solid state phased array; no movement is required. Mobile communications (cellular and satellite) spot beams work under the same principal.
Of course some radars did physically move their dishes to stay locked on to a target. I'm in the middle of The Invention That Changed the World (spoiler alert: it was radar) and I was stunned to learn how well this worked with analog circuits. An SCR-584, paired with an M9 analog computer, could detect that a plane was moving out of the center of its conical scan, and then convert that into a signal to the motors that drive the dish (and its associated antiaircraft guns).
Thanks for pointing me to that book - it sounds like something I'd read.
Yeah phased arrays have probably been the rule for decades at that price-no-object level.
Even at the consumer level, there have been phased-array marine -sonars- (e.g. Interphase brand product line) for at least ten years for "only" 4-digit prices. Spatial resolution is of course tied to the number of elements but they do present more information that your typical 1-d "fish finder."
It acutally makes the sim quite fun to play, although you do have to get past that learning curve. I think for me it was the learning part that was kind of fun too
Another interesting aspect is the Lock-On detection of the enemy aircraft. Aircraft are able to identify when they're being tracked by other aircraft or homing missles. [1]
Upon reading of RWR and its delights, at least one part of me, the techno-dweeb, goes "weeeh!" ..
Another part, more of a hippy tree-hugger, goes "wish we were using this to figure out where to drop the water/medicine/books instead of BOOMB devices" ..
I mean, seriously. Tell us where to drop the books, and BOOM there it is: how it should be.
Good response, worth the read. Heck the response alone could justify their own article.
As an aside: I hate quora' site design so much I have blacklisted it using Google Personal Blocklist. Somehow I dislike it more than Experts Exchange (which is also blacklisted), it is just super cluttered with nonsense, rolls into the comments section without warning and rarely offers good content (see Experts Exchange again).
That being said Yahoo! Answers also rarely has good content but at least with Yahoo! Answers you can determine that with a glance. You visit the page and you can see the answer (or lack of answer). So Yahoo! Answers remains in my search results, Quora and Expert Exchange have been vanished indefinitely.
PS - Quora also likes to spawn pop ups whenever you click anywhere on the page for no real reason (just asks for your Quora login details). For someone who randomly highlights blocks of text while reading this is pure hell...
The unusual number of complaints on this thread were actually because of a bug causing a bad experience. This was our fault and it has been fixed.
We don't mind the change of link - we just want knowledge shared on Quora to get to as many people as possible and we don't mind if it happens on other sites. But I wanted to let you guys know that this was a bug and the behavior is back to normal (nothing with share=1 will ever require viewers to sign in / trigger this level of complaints). There can be so much negativity here that it can be hard to tell the difference between general hate (as radmuzom suspected) and a real problem, but in this case it was a real problem.
Well, given that the people here seem to have extreme hatred for Quora, they should not be visiting the site or do it on the terms set by Quora. I find it extremely hypocritical that they would want to read extremely interesting content which is often available there. Given that the original link was there in Quora, I don't see any reason why it should be changed - if people find it bad, they should not click the link or flag it so that it disappears.
I remember you used to see experts exchange or the like come up in search results and you could block it right there, in your search results without having to go to a separate page. Since they've hidden it, I honestly thought they'd removed the ability to block websites. Thanks for letting me know I just have to hunt for it.
I wonder why they removed that option from search results?
I really don't like the typography. In one page you'll find serif, sans-serif, all-caps, bolded, italicized, black links, blue buttons, green buttons, barely visible gray links.. it's a mess. Every revision they make to the home page (top stories) feed seems like a step backward in readability.
The content is usually good but it's still annoying that Quora impedes you from sharing it with others that aren't also on Quora.
So true. And upvoted - Quora is one of my finest discoveries in the last two years. It has taught me immensely about various cultures around the world, and while opinion should always be taken with a grain of salt there are enough "factual" answers too.
They are also a brilliant engineering company, and have some of the best web-based tools available to those who are asking questions and providing answers. No other site - I repeat, no other site including StackExchange provides as much functionality as Quora. The only downside is that they are sometimes a bit slow.
For a forum who talks about free market at the drop of a hat, and tends to defend Amazon in every discussion; my message to get Hacker News is - GET LOST!! We are happy with the real name policy and we are happy to log in to browse the site. If you don't like it, don't use it. Good riddance.
This was a great read until I reached the truncated bottom of the post.
God I hate Quora. There's the `share=1` flag but still, the end of the article is truncated and you're asked to login.
Quora wouldn't piss me off so much if they were not so annoying about me logging in and linking a social account, if they didn't post crap from my friend's facebook account who do have an account, send me spam about whatever people I know might have done (or not done) on their platform.
This is trying to gather users by pissing them off. Likely I'd have created an account since if it weren't for their aggressive behavior.
That's odd. On the page with the signup box look for the id "__w2_LG4FatW_modal_signup_wrapper" and delete the whole div, that'll get rid of the box allowing to you to continue reading the top answer but not the others.
Off Topic: Man! Reading this answer so makes me want to play those FlightSim games of the yesteryears like Apache Havoc, Commanche, Jane's F/A 18 Hornet etc etc. Does anyone have any suggestions for a modern Flight Sim game? Thanks!
For being a "Wing Commander"-like game, Strike Commander was surprisingly good and detailed. The manual was pretty interesting, with lots of information similar to the Quora answer.
The hardcore side of combat flightsim gaming for me was Su-27 Flanker (http://www.mobygames.com/game/su-27-flanker), published by SSI. So hardcore I never actually managed to complete a full mission! It was a bit dry, without any campaigns or any kind of career tracking, but man was it detailed! It made me fall in love with the real-life Flanker.
And of course, Falcon 3.0 by Spectrum Holobyte. Another awesome flightsim I spent a lot of time with but never managed to complete a single mission with. It was obvious this sim was a work of love.
Yes, Comanche was awesome back in the day. First 386 protected mode game I had and it pushed my 486DX-50 to the hilt. I also had the Thrustmaster stick and throttle, and 8-bit sound blaster. Ahh, the good old days.
There are two main options at the moment, with many simmers enjoying both:
1) DCS World (https://www.digitalcombatsimulator.com/en/world/) is the "framework" and comes with some free aircraft. There are paid aircraft options both 1st and 3rd party; DCS A-10C being the most popular.
I don't know much about combat sims, but I have a blast with X-Plane. It's highly realistic and can practically scale to any performance computer. It has some combat-sim aspects, but I haven't played with that stuff enough to comment. Flying is tough enough for me without the weapons ;)
Fully expecting flightsims to make a glorious comeback with Oculus' full availability. It is too well suited to games which require you to sit still, and have your hands on controls.
Unfortunately, the Oculus has some issues with full flight sims. It's still extremely neat tech, but I don't think I'll be giving up head tracking for it any time soon.
First, there's the resolution issue. I've only used DK2, but its resolution was so low that I was unable to read the dials/HUD without getting my face super close to them, which presents major issues when trying to maintain situational awareness.
Second, no matter how many buttons and switches you have on your HOTAS, you're going to have to manipulate something with your keyboard/mouse at some point. This causes some obvious problems when you have an Oculus strapped to your head.
I probably ratched up 100 hours or more on F-117 Steal Bomber, for DOS, back in the day. There is no reason not to play it even now, still today: consider the pixelation more of a consequence of "HUD"/"IFR" and be done with it. Fact is, those old games still run, and still work for simulating the death cult and its machines ..
Falcon 4.0 is nothing short of amazing. It has been under non-stop development by the official developers and the community (thanks to a source code leak) since 1984.
Many of the community developers are former pilots and avionics techs.
What does it normally do? I gave up and created a Quora account a while back. Even on Incognito, though, hitting the link without the share on it looks normal and doesn't do anything particularly annoying.
I don't know any numbers, but it seems as if Stack Exchange is far more popular, especially as an information database for employees and students.
Quora has the opportunity to do the same, but I think the specific stack exchange communities offer a better partition between topics. Quora does it's best to show you targetted questions/comments, whereas StackExchange sites just throw you wherever you showed up (which, if by search, is usually a better choice)
A good example : I once answered a fringe question about the Dalai Lama on Quora, now many of the questions i'm tasked with giving answers to are spiritual in nature, and of absolutely no interest to me. It's the same search bubble problem that YouTube/Google runs into occasionally. Things like that make me prefer more 'basic' sites like StackExchange networks.
Stack Exchange made the brilliant move of having disparate communities with a defined (and passionate) audience for each. This makes selling targeted advertising much easier. Ex. Stack Overflow is probably one of the best places to reach developers with job ads—hence they can charge a lot more for that than generic display ads.
This is all pure speculation, but I wouldn't be surprised if Stack Exchange's RPU would be 10x Quora's.
I usually just open dev tools and delete the div that contains the modal dialog and gray-out background (its ID is along the lines of "Modal_signup_wrapper"). You still won't be able to read past the first answer, but at least you'll get all of that answer's content.
Interesting(I didn't read the whole article because I'm not logging into Quora). I wonder what the state of the art is? Certainly we have tech now to get all the info on all the aircrafts? I would think that software could be employed to fill in the gaps and extrapolate the info at the least. What with 3d video tracking and the like at the levels they are at today.
There's growing number of ways, both active and passive, that targets can be tracked or future positions predicted. One of the answers on that page hints at this, the other answer is misleading and often not how it's done in many modern systems.
Source: engineered parts of these systems before.