Cloud altitude measuring apparatus

摘要

A cloud altitude measuring means for detecting the existence of and the distance to a cloud comprising a light emitting means, a light receiving means, a plurality of integrators activated at separate time intervals to receive the output signal from the light receiving means, a signal summation device to receive and determine the difference between the signals in the said integrators, and a signal processing circuit to receive the output signal from the signal summation device, which circuit comprises a memory circuit to store a first series of measurement value pulses from said summation device and a comparison device for comparing the first series of measurement value pulses stored in the memory with a second time delayed series of measurement value pulses to detect a cloud echo when the comparative difference between the measurement value pulses exceeds a specified value.