科学与数学gizmodo.com
战斗机如何锁定目标，目标又如何察觉
How fighter jets lock on, and how the targets know (2014)
2014 — 2021，它一次次回到首页
黑点是上首页（≥ 50 分）的那次投稿，空心点是没冲上去的投稿，点越大分数越高。
导读
这篇 Gizmodo 的科普文章解释了战斗机雷达如何锁定目标，以及被锁定的目标如何通过雷达告警接收机察觉并做出反应，涉及雷达扫描与跟踪模式、多普勒效应等原理。文章时隔七年两度登上 Hacker News 首页，是空战电子对抗入门的经典读物。
为什么经久不衰：它用通俗语言讲清了雷达锁定与告警的底层原理，这些物理和工程机制多年不变，至今仍是理解现代空战和电子对抗的最佳入门材料。
HN 评论精选
推荐游戏 VTOL VR，并详细解释了利用多普勒频移“凹槽机动”摆脱雷达锁定和导弹跟踪的原理。
如果你有 VR 头显想玩玩文中描述的设备，推荐 VTOL VR：系统要求低，用 VR 实现了虚拟摇杆油门，物理仿真相当好，文中讲的东西游戏里都有。这游戏教会了我“雷达凹槽机动”：雷达靠多普勒频移探测目标，而地面的多普勒频移约等于飞机自身速度。假设你在高空被锁定、导弹已发射，你可以侧转机身，以 90 度角飞向来袭导弹——这样你的多普勒频移就和地面一样，混入地杂波中被雷达滤掉，导弹就会丢失目标。
oehpr查看英文原文
If you happen to have a VR headset and are looking to play around with the toys described in the article, I recommend VTOL VR. It has pretty low system requirements, and takes advantage of VR to create a virtual hotas (It is much more effective than you would expect). The physics simulation is, to my understanding, very good. And everything described in this article is present in the game to be played around with. VTOL VR taught me about "Radar Notching". The article briefly mentions how radar can actively detect the doppler shift of targets. If you think about it, the doppler shift of the ground would be neutral, right? Or roughly the speed of the aircraft. So lets say you've been locked on by a fighter at high altitude and they've fired a radar seeker at you. Your backdrop is the ground, it can pick you out because you're moving so fast. So what you do is bank your aircraft to fly at a 90 degree angle to the oncoming missile. Now your doppler shift is the same as the ground and you blend in, the radar filters out the ground because of it's expected speed, which is now the relative speed you are moving. You get "notched out", and the missile will lose track.
业内人士指出“锁定”本质是基于置信度的预测，而非字面上的锁定，且现代跟踪手段远比文章描述的多样。
系统其实并没有像字面那样“锁定目标”。它是在做预测：在一定的置信度下，根据当前参数，判断发射导弹能否消灭目标。如今有越来越多主动和被动手段可以跟踪目标或预测其未来位置。我参与设计过这些系统的部分部件。
reduce查看英文原文
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. Source: engineered parts of these systems before.
战斗机 HUD 刻意保持单色简洁风格，因为高压环境下人眼对颜色的辨别力会下降。
有点跑题，但关于战斗机 HUD 我了解到的最有趣的事情之一是：它们至今仍像早期计算界面，避免用颜色和图形来标示重要信息，原因是人在高压情况下对颜色的感知能力会下降。
Saint_Genet查看英文原文
This is largely off topic, but one of the most fascinating things I’ve ever learned about fighter jet HUDs is the reason they still look like early computing interfaces and avoid using color and graphics to signify important information is that human ability to detect color goes down when in high stress situations.
读者追问锁定后天线如何持续精确指向目标，并猜测是螺旋扫描加最强回波追踪的机制。
我本来希望看到控制系统如何调整高定向性天线的朝向，以便在从扫描中选定目标后持续最大程度地“照射”目标。有人能描述这个方案吗？比如：进入“锁定”后，天线画小圈扫描，并把中心点向回波最强的方向移动，同时考虑噪声的影响。
OldSchool查看英文原文
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.
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