Research on forward scattering visibility sensor

A visibility sensor is designed based on the principle of forward scattering, and the sensor transmitting unit is equipped with one photodetector for light intensity feedback and the other photodetector for monitoring the light transmittance of the lens, which can produce stable emitted light and monitor the light transmittance. The principle of phase-locked amplification is used to measure the visibility in the receiving unit. The self-developed visibility sensor is compared with Vaisala PWD20 visibility sensor. In the range of $10 \sim 10000$ meters, the measurement deviation of one minute visibility data is basically within ± 10%, and the measurement deviation of ten minute data is within ± 5%; In the range of 10000 ∼ 20000 meters, the measurement deviation of one minute data is basically within ± 20%, and the measurement deviation of ten minute data is within ± 10%. The visibility trend measured by the Vaisala PWD20 visibility sensor and the self-developed visibility sensor is consistent, which proves that the self-developed visibility sensor can meet the needs of visibility monitoring.