A technique called interferometric synthetic aperture radar (InSAR), used to detect tiny movements of Earth's surface from space, is taking off. Individual GPS stations can track surface movements of less than 1 millimeter, but InSAR can measure changes almost as subtle across a swath hundreds of kilometers wide. With InSAR, scientists are tracking how ice streams flow, how faults slip in earthquakes, and how the ground moves as fluids are pumped in or out. And the flood of InSAR data is growing fast. Since 2018, the number of civil and commercial SAR satellites in orbit has more than doubled. And at least a dozen more are set to launch this year, which would bring the total to more than 60. With the help of computing advances that make data processing easier, the satellite fleets may soon be able to detect daily or even hourly surface changes at just about every patch of ground on Earth. And that will enable new applications: near–real-time monitoring of the structural integrity of dams and buildings, along with disaster response efforts for floods and fires. Analysts value the SAR market at roughly $4 billion and expect that figure to nearly double over the next 5 years. Many believe InSAR will eventually underpin our daily lives.

一种用于探测太空中地面微小运动的称为干涉式合成孔径雷达（InSAR）的技术正在兴起，单个GPS站可以跟踪不到1毫米的地面运动，但是InSAR可以测量整个范围内的微小变化几百公里宽。借助InSAR，科学家们可以追踪冰流如何流动，断层在地震中如何滑动以及随着流体被抽入或抽出而地面如何运动。而且InSAR数据的泛滥正在迅速增长。自2018年以来，在轨民用和商业SAR卫星的数量增加了一倍以上。预计今年还将推出至少十二种产品，这将使总数超过60家。借助先进的计算技术，可简化数据处理，卫星机队可能很快就能检测到地球上几乎每一个地面的每日甚至每小时的地表变化。这将启用新的应用程序：对水坝和建筑物的结构完整性进行近实时监控，以及针对洪水和火灾的灾难响应工作。分析师对SAR市场的估值约为40亿美元，并希望在未来5年内，该数字将增长近一倍。许多人认为InSAR最终将支撑我们的日常生活。