The particular app in question is a subway route finder that shows route signs when you point your phone one direction or another.

这里所提到的应用是一款地铁路线查询器，当你将手机指向一个方向时，它就会显示出路线标志。

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Function test and calibration self-heterodyne curve for direction finder on sea trial.

航行试验中测向仪效用试验及自差曲线校正。

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This article discourse upon the principle and system construction of Interferometer Direction Finder.

论文介绍了多波道干涉仪测向的系统构成及其原理。

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He invented the radio direction finder, autopilot and the first fully automatic aircraft landing system.

FORBES: The Bill Lear I Knew

During the second world war at Marconi he was part of the team that invented a radio direction-finder which was fitted to British bombers.

ECONOMIST: Christopher Cockerell