Detection distance is an important index of infrared imaging system, and meteorological parameters are one of the main factors affecting the detection distance. The calculation model based on the detection distance of infrared detector point source is calculated by using MODTRAN software. Peel off the factors associated with the environment. Selecting typical weather conditions to calculate the detection distance of infrared detector's point source target. The detection distance under different atmospheric parameters is obtained, and the sensitivity analysis is carried out between the detection distance of infrared detector and the parameters of the meteorological environment. The results show that the detection distance is influenced by the parameters such as temperature, humidity, pressure, visibility, wind speed and so on, and is linearly related to these meteorological parameters.
Cloud is a common natural phenomenon in the sky, and has an irregular and arbitrary appearance. Cloud has serious interference with optical sensors, so it is meaningful to research the optical characteristic of cloud. In this paper, lidar was used to measure the vertical atmosphere, and the atmospheric extinction characteristic data were obtained by retrieving the measured data. During the measurement period, clouds appeared in the sky, and it information was recorded. The extinction characteristics of cloud, the height of cloud bottom and the height of cloud top were given, and the transmittance and optical thickness of the cloud were further analyzed.
Typical natural backgrounds include land, sea, desert, sky and so on, and experimental measurement is an effective means to obtain background radiation data. Because the background infrared radiation is affected by season, weather and the angle of solar radiation, it is necessary to collect environmental parameters at the same time during testing. The screening and collection of major environmental parameters is crucial for subsequent radiation data processing. In view of this problem, first of all, the influence of environmental reference on background infrared radiation was theoretically calculated by MODTRAN software, and the main parameters were screened out. A test program for radiation measurement of natural background is formed, which is used as a reference for the design of background infrared radiation measurement.
Cloud is an important natural phenomenon, and its radiation causes serious interference to infrared detector. Based on fractal and statistical data, a method is proposed to realize cloud background simulation, and cloud infrared radiation data field is assigned using satellite radiation data of cloud. A cloud infrared radiation simulation model is established using matlab, and it can generate cloud background infrared images for different cloud types (low cloud, middle cloud, and high cloud) in different months, bands and sensor zenith angles.
Lidar is used to measure atmospheric aerosol, and horizontal visibility is retrieved based on lidar measurement data. In the process of visibility retrieval, it’s manually ascertaining linear region that existed in the curve of data, which is difficult for computer. An algorithm is presented to ascertain the linear region and gives out the horizontal visibility automatically. A group of lidar measurement data is processed by the algorithm, and the results show its practicability.