These instruments are capable of detecting signals on the Earth's surface transmitted from emergency beacons referred to as emergency locator transmitters (ELTs), emergency position-indicating radio beacons (EPIRBs) or personal locator beacons (PLBs).
8. 这些仪器能够发现地球表面从紧急信标（称为紧急定位发射机、紧急位置指示无线电信标或个人定位信标）发出的信号。