METHOD FOR MEASURING TEMPERATURE OF SUBMARINE CABLE

摘要

PURPOSE:To measure the temperature of a submarine cable by transmitting an oscillator output from a ground station, allowing a submarine repeater to transmit a frequency-modulated output is response to the reception level to a succeeding repeater and allowing a ground station at the termination to receive each frequency. CONSTITUTION:The ground station T1 is provided with an oscillator F0 for supervision. The output of the oscillator F0 is transmitted at a prescribed level. The level of the output is changed by the loss of the submarine cable C1. The loss depends on the temperature. Each submarine repeater R has an oscillator Fn of a specific frequency. The submarine repeater R extracts the frequency component of a reception signal by using a detection circuit DET, transmits the change to the oscillator Fn so as to attain frequency modulation. The frequency- modulated output is transmitted to the succeeding repeater at a prescribed level. The frequency-modulated outputs are detected and the temperature of each cable section is detected depending on the amount of modulation.