The trials are designed to see how passive radar could support Britain's air-traffic management.

实验项目的目的在于找出被动雷达能够如何帮助管理英国的空中交通。

It is a form of “passive” radar, which goes back a long time.

属于存在已久的“被动”雷达中的一种。

One difficulty is that passive radar relies on a third party for its signals.

被动雷达的一个难题在于它要依靠第三方提供的信号。

The growth in radio and television broadcasts—especially with digital and high-definition TV—now provides an enormous amount of high-frequency radio waves which are ideally suitable for passive radar systems.

现在无线电和电视广播的增长（尤其是数字电视和高清电视出现以后）提供了海量的高频电波，这些非常适合用于被动雷达系统。

With growing demand for wireless devices, passive radar would allow the radio spectrum currently used by conventional radar to be freed up and auctioned off to mobile operators.

随着无线设备的需求不断增加，被动雷达能够将目前用于传统雷达的无线电频谱解放出来，然后再拍卖给移动运营商。