中国声称可以追踪美国F-22战机 [美国媒体]

Stealth No More?: China Claims It Can Track U.S. Air Force F-22 Raptors

中国声称可以追踪美国F-22战机



The laws of physics essentially dictate that a tactical fighter-sized stealth aircraft must be optimized to defeat higher-frequency bands such the C, X, Ku and the top part of the S bands. There is a “step change” in a Low Observable (LO) aircraft’s signature once the frequency wavelength exceeds a certain threshold and causes a resonant effect. Typically, that resonance occurs when a feature on an aircraft—such as a tail-fin — is less than eight times the size of a particular frequency wavelength. Effectively, small stealth aircraft that do not have the size or weight allowances for two feet or more of radar absorbent material coatings on every surface are forced to make trades as to which frequency bands they are optimized for.

根据物理定理，战术战斗机大小的隐形飞机必须优化才能躲避C、X、Ku和S波段上部等高频波段的侦测。一旦频率波长超过某一阈值并引起谐振效应，低可侦测飞机的信号就会发生“阶跃变化”。通常情况下，当飞机上的某一特征(如尾鳍)小于8倍特定频率波长时，就会产生这种共振。实际上，小型隐形飞机如果没有足够的尺寸和重量，就要在每个表面上覆盖两英尺或更多的雷达吸收材料，来对它所针对的频段进行优化。

Therefore, a radar operating at a lower-frequency band such as parts of the S or L band—like civilian air traffic control (ATC) radars—are almost certainly able to detect and track tactical fighter-sized stealth aircraft. However, a larger stealth aircraft like the Northrop Grumman B-2 Spirit, which lacks many of the features that cause a resonance effect, is much more effective against low-frequency radars than, for example, an F-35 or F-22. Typically, however, those lower-frequency radars do not provide what Pentagon officials call a “weapons quality” track needed to guide a missile onto a target. “Even if you can see an LO [low observable] strike aircraft with ATC radar, you can’t kill it without a fire control system,” an Air Force official had told me.

因此，在S或L等较低频段允许的雷达（如民用空中交通管制雷达），几乎肯定能够探测和跟踪战术战斗机大小的隐形飞机。然而，像诺斯洛普•格鲁门公司公司生产的B-2“幽灵”这样的大型隐形飞机，缺少很多引起共振效应的特征，因此在对抗低频雷达方面要比F-35或F-22等飞机强得多。不过，通常情况下，这些低频雷达不能提供五角大楼官员所谓的“武器质量”跟踪，也就无法引导导弹对准目标。一位空军官员曾告诉我:“即使能用空中交通管制雷达看到一架低测性攻击机，没有火力控制系统也无法进行击落。”

That being said, Russia, China and others are developing advanced UHF and VHF band early warning radars that use even longer wavelengths in an effort to cue their other sensors and give their fighters some idea of where an adversary stealth aircraft might be coming from. But the problem with VHF and UHF band radars is that with long wavelengths come large radar resolution cells. That means that contacts are not tracked with the required level of fidelity to guide a weapon onto a target. As one U.S. Navy officer rhetorically asked, “Does the mission require a cloaking device or is it OK if the threat sees it but can’t do anything about it?”

话虽如此，俄罗斯、中国和其他国家正在研发可以采用较长波长的先进的超高频(UHF)和甚高频（VHF）波段早期预警雷达，这样可以提示其他传感器，可以让本国战斗机了解地方隐形战机的具体位置。但超高频(UHF)和甚高频（VHF）波段的问题在于，波长较长的雷达分辨单元更大。这意味着对目标的追踪没有达到可以引导武器进行打击的精确度水平。正如一名美国海军官员反问的那样，“这次任务需要隐形装置吗，还是说对手看到却无能为力就可以了?”

Traditionally, guiding weapons with low frequency radars has been limited by two factors. One factor is the width of the radar beam, while the second is the width of the radar pulse—but both limitations can be overcome with signal processing. Phased array radars—particularly active electronically scanned arrays (AESA)—solve the problem of directional or azimuth resolution because they can steer their radar beams electronically. Moreover, AESA radars can generate multiple beams and can shape those beams for width, sweep rate and other characteristics. Indeed, some industry experts suggested that a combination of high-speed data-links and low-frequency phased-array radars could generate a weapons quality track.

传统的低频雷达制导武器一直受到两个因素的限制。一个因素是雷达波束的宽度，而另一个是雷达脉冲的宽度。但是这两个限制都可以通过信号处理来克服。相控阵雷达——尤其是有源电子扫描雷达(AESA)——能够通过电子控制雷达波束，从而解决方向或方位分辨率的问题。此外，有源电子扫描雷达可以产生多个波束，并可以改变波束的宽度、扫频频率等其他特性。事实上，一些行业专家认为，高速数据链路和低频相控阵雷达相结合可以产生武器质量跟踪。



That effectively means that stealthy tactical aircraft must operate alongside electronic attack platforms the like Boeing EA-18G Growler. It is also why the Pentagon has been shoring up American investments in electronic and cyber warfare. As one Air Force official explained, stealth and electronic attack always have a synergistic relationship because detection is about the signal-to-noise ratio. Low observables reduce the signal, while electronic attack increases the noise. “Any big picture plan, looking forward, to deal with emerging A2/AD threats will address both sides of that equation,” he said.

这实际上意味着，隐形战术飞机必须与电子攻击平台一起作战，比如波音EA-18G“咆哮者”。这也是为什么五角大楼一直支持美国在电子和网络战方面的投资。正如一名空军官员说得那样，隐形和电子攻击总是具有协同关系，因为探测就是关于信噪比得。低测性降低了信号，而电子攻击增加了噪声。他表示:“未来，任何应对中国武器威胁的宏伟计划，都将解决等式的两边。”

译注：A2/AD五角大楼造的新词指代中国武器。现在被称为反介入和区域封锁武器。

shaktiman
Interesting but Shaktiman predicted this kind of technology a few years ago. Is it perfected? Probably not. But is it probable, absolutely yes. For every material weapon there will always be a counter-weapon.

有点意思，不过作者几年前就预测到了这种技术。现在完善了吗?也许没有。有这种可能吗，绝对可能。武器这东西就是一物降一物。

Kaipo1 hour ago
DARPA is currently perfecting the Swarm Technology that will easily defeat any radar system. Picture a B1 or B2 Bombers launching dozens of stealth cruise missiles then these stealth cruise missiles contain thousands of tiny smart drones that communicate with each other forming a large swarm of with hundreds or thousands of them with each drone having enough destructive power to destroy buildings, weapons materiel.

美国国防部高级研究计划局目前正在完善蜂群技术，该技术可以轻易击败任何雷达系统。想象一下B1和B2轰炸机发射几十个隐形巡航导弹，这些隐形巡航导弹包含成千上万的小型智能无人驾驶飞机,这些无人机可以相互沟通形成一大群与成百上千无人机群，任何一个无人机都能摧毁建筑,武器装备。



Binh
@HelloWorld . We can track chinese communists lies but we cannot shoot them down

我们可以追踪中国的谎言，但是我们无法将其击落。

Billy
Really@ Helloworld? That's funny because I have worked in radar both as an analyst and as an electronic warfare specialist for almost 30 years and nothing Nick said is false. How long have YOU worked in the field?

真的吗？有意思的是，我从事雷达领域工作已经快30年了，做过分析员和电子战专家，Nick说得一点都没错。你在这个领域做了多久了？

MLar
People, while this article is 2 years old, it is worthwhile to raise a very important point. Stealth aircraft CAN be spotted and attacked by ground based defensive systems using old fashioned long wave length radar rather than modern millimeter wavelength radar. Why do I say this? Because it's been done.

虽然这篇文章已经有2年的历史了，不过文章提出一个非常重要的观点。地面防御系统使用老式长波雷达而不是现代毫米波雷达，就可以发现和攻击隐形飞机。我为什么这么说?因为之前成功过。

In 1999 during the Yugoslav War, a USAF F-117 Nighthawk was shot down (by of all things) a Yugoslavia anti-aircraft missile battery armed with a local version of the outdated (we thought) Soviet SA-3 surface to air missile. What's more, the 117 landed upside down but largely intact and the Yugoslav government was kind enough to share a few large pieces with Russia and China. Scoff all you want, but China's claim is entirely plausible and possible.

1999年，在南斯拉夫战争期间，一架美国空军F-117夜鹰战机被南斯拉夫防空导弹连击落，该导弹连配备了一枚我们认为过时的当地版的苏联SA-3地对空导弹。更重要的是，这家架F-117飞机倒着着陆，基本保持完好无损，南斯拉夫政府也很友好地与俄罗斯和中国分享了几块大飞机残骸。随便你们嘲笑，但中国的主张是完全合理和可能的，如果不太可能的话。



Sherwood O
Is that why we "accidentally" bombed the Chinese Embassy?

这就是我们“不小心”轰炸了中国驻南联盟大使馆的愿意吧？

Eustace
One F117 was shot down, partly because Air Force mission planners had gotten lazy and complacent. They had the pilots flying the same paths at almost the same ties daily. With that information the Yugoslavians were able to get one plane. Afterwards they didn't get anymore because the US changed up where they attacked from and when.

F117被击落，部分原因是空军任务策划者懒惰和自满。他们让飞行员每天几乎按照相同的航线飞行。有了这些信息，南斯拉夫人就能击落飞机。从那以后，他们再也没有击落过飞机了，因为美国不断地改变进攻的地点和时间。
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