Tossa on vaikka tollanen juttu josta lainattu alle:
http://breakingdefense.com/2012/11/will-stealth-survive-as-sensors-improve-f-35-jammers-at-stake/
“People need to understand stealth is not invisibility,” Deptula told Breaking Defense. As current sensor technology improves, he said, “you’re going to be able to detect aircraft with current levels of low-observability at further distances.” T
hat said, non-stealth planes are much bigger targets, he said: “It’s a piece of cake for an adversary with a sophisticated air defense system to engage and kill a 4th generation aircraft; it’s very difficult for them to do that with a 5th gen aircraft. Will it get easier in the future? Possibly.”
“You can’t make something disappear, all right?” echoed Friedman. “What you can do is reduce the signature you get back [on the enemy’s sensor screens]. More powerful processors buy you back part of the signal” – and thanks to Moore’s Law, the processing power available to do that doubles every 18 months. The more powerful the processors and the more sophisticated their algorithms, the more effectively they can sift meaningful data out of the static. And no matter how stealthy an aircraft is, it still makes some noise, it still emits some heat as infra-red radiation, and – most critically – it still reflects back some portion of an incoming radar beam.
Not that all radars are created equal. Even back in the 1980s,
author Andrew Cockburn warned that, ironically, the Soviet Union’s oldest, crudest radars might detect stealth bombers that newer systems missed. Stealth aircraft rely on carefully designed shapes and thin surface coatings to baffle incoming radar beams. But the lower the frequency of the incoming radar, the longer the wavelength, which means the less it reflects such subtleties at all: It’s essentially too stupid to be tricked.
The upside is such relatively crude radars may detect a stealth aircraft is out there somewhere, but not accurately enough to shoot it down. The low-frequency, long-wavelength radars that are most likely to see through stealth are, for the same reasons of physics, the least precise.
They’re also too big to fit in anything but a ship or a fixed ground installation, where they are typically used to give warning that aircraft are in the general area. Actually tracking and hitting a target depends on smaller, shorter-wavelength radars which can fit in, say, an interceptor aircraft or surface-to-air missile and which offer more precision but are also more easily baffled by stealth technologies.
“Just because you can see someone now doesn’t mean you can kill them,” said Deptula. “Acquisition radars, which are what people generally tend to focus on, are only one element in an adversary’s air defense equation.”
After a target is initially “acquired,” he went on, “you need to be able to track the asset to then get to a firing solution; then you need to transfer that tracking data to the missile, which then needs to be able to acquire and track the aircraft [after it launches]. Presuming that the missile can track… now the fuse needs to be able to detect the aircraft” in order to detonate at the right time.
Break any link in that “kill chain,” and the stealth aircraft survives, even if it’s seen. So while stealth can’t defeat all the radars all the time, it doesn’t need to.
The problem is what happens when all the radars are working together in parallel instead of in a series. Rapid advances in computing technology don’t just improve the individual radars. They also make it easier to share data among multiple sensors of multiple types – radar, infra-red, visual, acoustic – and thus put together scattered clues into a picture that’s clear enough to kill.
“If you have a lot of radars working together, then you add up all of those very momentary detections and you get a track,” said Friedman. With a command-detonated or time-fused missile instead of a radar-homing one, he went on, you can then fire at the predicted position of the target, without needing a radar lock on its precise location. This technique is less precise – the equivalent of shooting at a strange noise in the dark instead of having the target in your sights – but it can be effective. It may, for example, have been how the Serbians shot down an F-117 stealth fighter during the Kosovo air war in 1999.
The issue is not just technology but tactics.
Stealth aircraft still need to aim for the weak points in an enemy air defense system to fly through the gaps in radar coverage; it’s just that those gaps will be larger for them than for conventional planes, because the enemy radars can only detect them at shorter ranges. Conversely, non-stealthy aircraft can still penetrate sophisticated air defenses — if there are enough of them to take losses and still complete the mission, and if they’re accompanied by enough jamming aircraft to blind and baffle the enemy radars. The question then becomes whether a small number of stealth planes gives you more bang for the buck – and fewer US casualties – than a larger force of non-stealth ones.
Sure, said Deptula, “it’s less expensive on a per-unit cost basis to buy more F/A-18E/Fs or new F-15s or new F-16s than to buy F-35s or F-22s — but when you get all of those fourth-generation aircraft shot down the first day, what’s your cost-effectiveness now?”
Olen tismalleen samaa mieltä torjuntakyvyn olemassaolon tarpeesta. Raha se puutteellaan köyhän kukkarossa loistaa...