Method and apparatus for measuring meteorological visibility and scattering of light, said apparatus utilizing common optics for transmission and reception

摘要

The invention concerns a method and device for measuring the meteorological visibility and the scattering of light. A light pulse is emitted into the atmosphere via an optical transmit system, the backscattered light returns via the optical transmit system after which its intensity and delay are measured. The waveform of the optical transmit pulse generated at the instant of its launching from within the apparatus is sensed in a manner that excludes any backscattered light originating from outside the measurement system, this signal is scaled for both its magnitude and phase so as to achieve a suitable feedback signal relative to the actual measurement signal and said feedback signal is subtracted from said measurement signal to avoid overloading of the receiver.