Electric Simulator Of Atmosphere Detection With Laser And Pulse Laser Frequency-Locking Peak Detector

Atmospheric Detection with Laser is one kind of techniques in remote sensing and detecting for the atmospheric parameters. The laser is emitted into the atmosphere, and then the backscattering optical signal is received by the lidar. The component of the atmosphere, the aerosol distribution, the cloud, the temperature and pressure of the atmosphere can be obtained by analyzing the backscattering signal.In this paper, an electric simulator of atmosphere detection with laser which is used to simulate the atmospheric backscattering signal of laser is introduced. The simulator is used to simplify the procedure of the lidar adjustment. The lidar return signal is finally available after all the optics and electronics components are integrated and well adjusted. In addition, this kind of test and debugging depends on the weather condition, and laser maintenance is also an important issue. After we have the electric simulator, the opt-electric converter, the AD card, the signal cable, and the software can be adjusted using the simulated laser atmosphere backscattering signal. Furthermore, researchers can test their signal digitizer and retrieval algorithm before the real experiment under all kinds of backscattering and extinction conditions which are little probability in normal observations. The thickness and altitude of the aerosol layer, the detecting range, and the signal intensity all can be adjusted.The second part of this paper, an adjustable laser pulse peak detector for the laser frequency locking is introduced. The frequency of the laser pulse can be adjusted from 10 to 10000Hz, and the laser pulse width is only 17ns. The peak value of the laser pulse can't be sampled by the AD card, and the rising time of the peak detecting chip which we can buy in the market is much longer than the rising time of the laser pulse. When the repetition frequency of the pulse laser is K quality, and the photodiode can be used to detect the peak value of the pulse laser, but the accuracy is low. When the petition frequency is under K quality, even less than 100Hz, the adjustable peak detector can be used to detect the peak value only. The peak detector can extend the pulse width quality from nanosecond order to millisecond order. As a result, the AD card can sample the peak value easily. Compared with general peak detector, the most obvious merits of the adjustable pulse laser peak detector are the adjustment and the short-response time. The response time is 4ns. The peak value of the pulse laser with repetition frequency from 10 to 10000Hz all can be hold by the adjustable pulse laser peak detector.