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Radar¹ Scans Detail North Korean Nukes

North Korea has promised to close its underground nuclear test site at Mount Mantap later this month. Shortly thereafter, President Trump² is set to meet North Korea's leader Kim Jong-un in Singapore.

朝鲜已承诺本月晚些时候，关闭在曼塔山地下核试验场。此后不久，特朗普总统将在新加坡与朝鲜领导人金正恩会面。

Regardless of how that goes, there’s a now an additional tool to investigate covert³ subterranean⁴ tests: radar. Specifically, a type called synthetic⁵ aperture⁶ radar, which works day and night, and through clouds.

无论如何，现在有一个额外的工具来研究隐蔽的地下测试设施：雷达。具体来说，就是一种叫合成孔径雷达的仪器，它可以在白天和黑夜以及云层中工作。

Scientists already use seismic⁷ data in their nuclear detective work. "We use the kind of techniques that earthquake seismologists use to figure some aspect of what that explosion did." Roland Bürgmann, a geophysicist at University of California, Berkeley. He says they can also measure isotopes⁸ in the air, as well as optical images pre- and post-explosion.

科学家们已经在他们的核侦察工作中使用了地震数据。“我们让地震学家来判断，有关爆炸的某些方面的技术。”加州大学伯克利分校的地球物理学家RolandBürmann说，他们还可以测量空气中的同位素，以及爆炸前后的光学图像。

Now Bürgmann and his team have used synthetic aperture radar data from German and Japanese satellites to gather more clues about North Korea's biggest blast, in September 2017. Comparing before and after scans of the test site, their analysis found that the mountain bulged⁹ a dozen feet in one direction, and sunk a foot and a half.

现在Bürgmann和他的团队，已经使用德国和日本卫星的合成孔径雷达数据，在2017年9月，收集有关朝鲜最大爆炸的更多线索。通过对测试地点扫描前后的比较结果，他们分析发现，该山在一个方向上，隆起了十几英尺，并沉没一个半英尺。

Using computational modeling, they then simulated what sort of blasts could have produced those movements. Their estimate: the blast was at least six times as strong as the bomb the U.S. dropped on Nagasaki in World War II. The details are in the journal Science.

然后他们使用计算机建模，来模拟可以产生这些运动的爆炸。他们估计：爆炸至少是美国在二战期间，投掷在长崎上的炸弹的六倍。详情请见《科学》杂志。

"I think our study shows this is an especially valuable observation that can be thrown into the mix." When the US and India launch their synthetic aperture radar satellite, called NIDAR, in 2020, we'll have even more of this new kind of data. The hope is that no unauthorized nuclear tests will take place to be discovered.

“我认为，我们的研究表明，这是一个特别有价值的观察结果，可以投入到混合研究中。”当美国和印度在2020年发射合成孔径雷达卫星NIDAR时，我们将拥有更多这种新的数据。希望不会发生未经批准的核试验。