Abstract:Large surface targets are mainly referred to the military vessels of more than 8×10⁶ kg displacement, typically such as aircraft carriers. The infrared radiation characteristics of aircraft carriers are presented. On the basis of the infrared detectors mounted on a synchronous satellite and the standard container structures carried by a large cargo ship, the ideas of design and application of a simulation test system for infrared radiation characteristics of large surface targets are proposed.

Abstract:At present, Acousto-Optic Tunable Filter (AOTF) infrared spectrometers have attracted more and more attention. The speed of obtaining spectral curves not only depends on the number of spectral sampling points, but also depends on the rate of spectral sampling. A circuit design method based on a precision low noise integral amplifying circuit is presented. Compared with the traditional lock-in circuit, this circuit has a higher sampling speed which is up to microsecond order of magnitude in theory. According to the above theory, the data are collected with the same signal intensity and different integral time first. Then, the data are collected with different signal intensity and fixed integral time. The experimental results show that the circuit has its sampling speed up to 10² μs magnitude.}

Abstract:The infrared radiation of typical rocket exhaust plumes and its characteristics are studied and the detection capability of the Space-Based Infrared System (SBIRS) is analyzed. According to the typical booster flight mode, a trajectory tracking and estimating model is established. The simulation result about the tracking and estimating capability of SBIRS is given.

Abstract:To meet the application requirements of high stability, miniaturization and low power consumption of ultraviolet (UV) sensors in space calibration and the technical indexes such as the stability less than 1‰ and stable time less than 3 minutes when the UV Light Emitting Diode (LED) calibration is carried out with a typical current of 200 mA, a method for using a digital control circuit based on FPGA to drive the UV LED and using incremental Proportional-Integral-Derivative (PID) for close-loop control is proposed. The current stability of the UV LED is tested and the error of current changing with time is obtained. The test results show that this system can make the UV LED be stable in 3 minutes with the stability of 0.2‰ which can meet the requirement of space UV calibration.

Abstract:The detection theory of a photon counting laser range finder system under movement condition is studied. The theoretical issues such as statistic distribution features and detection probability involved with the data processing of the system are analyzed. According to the ranging background under movement condition and the characteristics of echo signals of the system, the simulation signals containing target echo signals and noise echo signals which correspond to the statistic distribution features are generated by Matlab. On the basis of the research on the traditional data processing algorithms such as Poisson filtering algorithm, an improved algorithm based on raster filtering is proposed. The algorithm is used to process the simulated echo wave data. Finally, the noise signals distributing randomly throughout the detection space are filtered out effectively and the motion trajectory of the target is obtained. Compared with the traditional data processing algorithms, this algorithm is more effective in the processing of photon counting laser ranging data under movement condition.

Abstract:When a ship sails on the sea, a clear wake with a very long lasting time will be formed behind it. The length of the wake can extend to several thousand meters. The detection of ship wakes by infrared imaging has been a military reconnaissance technology to be developed prior in each military power in the world. Firstly, in view of temperature resolution and spatial resolution, the infrared detection condition of ship wakes is derived. Secondly, on the basis of infrared temperature measurement principle, the expression of equivalent temperature difference between the ship wake and the sea surface in non temperature stratified seawater is obtained. Finally, on the basis of the threshold signal-to-noise ratio and equivalent band number, the infrared detection probability of the ship wake is derived. The research results show that the ship wake can be detected in non temperature stratified seawater only when the detection zenith angle is larger. Moreover, the detection probability will increase with the increase of detection zenith angle.

Abstract:In summer, the deep convection motion over Tibetan plateau and its adjacent regions is most active. One deep convective system occurred over the southern slope of Tibetan plateau on July 12, 2009 is analyzed by using the data from two infrared channels of FY-2C meteorological satellite and the reanalysis data from ERA-Interim. The results show that because of the synthetic action of topographic lift and cyclonic pumping in upper atmosphere, the convective system over the southern slope of Tibetan plateau has a higher deep convection development altitude. At this time, if the water vapour in the lower part of the troposphere is transported upward to the top part of the troposphere, it would benefit the exchange of substance between the stratosphere and the troposphere. Both the position of a convective system over plateau and its adjacent regions and the distribution of temperature gradient and vapour gradient in lower part of troposphere have significant influences on the development of convective systems.

Abstract:The compression and detail enhancement of infrared images in high dynamic range is helpful to the improvement of the ability of human eyes to obtain key detail information in images. Therefore, it is one of the important research topics in the field of infrared imaging. To solve the problem that the traditional global tone reproduction can not present the detail layer and base layer properly, a scheme for local tone reproduction of infrared images is designed and a method for dynamic range compression and detail enhancement of infrared images based on superpixel segmentation is proposed. Firstly, the superpixel segmentation algorithm is used to segment an original infrared image into multiple self-similar subregions. Then, compression and detail enhancement are implemented for each subregion. The experimental results show that the method can compress and enhance infrared images in high dynamic range more effectively. Moreover, it can preserve the detail information of original images well while compressing images in high dynamic range.