Abstract:Geo-Oculus is a study approached by European Space Agency in 2008 with the objective to enable observations of the global environment and security combining high resolution and real-time monitoring in geostationary orbit. Its main tasks are disaster monitoring (floods, large landslides and storms), fire monitoring, algal bloom detection and water quality monitoring. In addition, the Geo-Oculus also has the ability of collecting oil slick environmental information and monitoring erosion/sediment transport on the European shoreline. The Geo-Oculus has the capability of high resolution and real-time observing. It also offers the images in more than 20 spectral bands covering UV (resolution of 40m), VS (resolution of 21m), VNIR, MIR and TIR (resolution of 750m). The Geo-Oculus study is a significant pre-study of the high resolution and real-time monitoring geostationary satellite that will steadily establish the foundation of further detailed design and research.

Abstract:The development status of metal/mercury cadmium telluride (Hg1-xCdxTe, MCT) contacts including basic concepts, growth structure, chemical reactivity and electrical properties is presented. There are two types of metal/MCT contacts: electronic (ohm) type and rectifying (Shottky) type. Ohm contacts are the important parts of MCT infrared detectors. They can determine the performance and reliability of MCT devices. Ohm contacts have low resistance and good adhesion to MCT material. They can keep stable behavior against thermal cycling. Since the metal with a larger work function is needed, the contact is difficult to realize for p-type MCT. For n-type MCT, the contacts can be realized with a large variety of metals.

Abstract:The environment in which an aerial infrared camera operates is studied and the fact that when the camera operates at high altitude, the variation of temperature and atmospheric pressure can cause the focus of the camera to be changed and hence affect the imaging quality is pointed out. The effect of temperature and atmospheric pressure on the imaging quality of the camera is summarized. According to the features of the operation environment of the camera, the rules of temperature and atmospheric pressure causing the camera to be defocusing are analyzed respectively. An approximate calculation method is proposed and is verified in test. For different cameras, the corresponding convergence compensation methods are given. This work is of a certain reference value to the development of infrared cameras.

Abstract:The disturbance performance of smoke against infrared imaging and tracking needs to be verified through field test. The field test includes the use of a given smoke and a moving target, the reasonable planning of the relative positions of the smoke, target and imaging sensor, the changing of the releasing time and condition of the smoke and the test of the extinction and disturbance effectiveness of the smoke. According to the data obtained by the infrared imaging sensor, the extinction and disturbance model of the given smoke is verified and revised. Its infrared disturbance rule is derived. This work provides reliable basis for the correct use of the given smoke and the study of its effectiveness in disturbing infrared imaging and tracking.

Abstract:The influence of temperature on an infrared optical system is analyzed. The optical instruments for military use are usually used in a wide range of temperature. Therefore, to eliminate image plane defocusing, an effective temperature compensation measure must be taken. The athermal design approach and principle of an infrared optical system are presented. According to the design parameters of a small infrared optical system, an athermal design idea for passive optical compensation is proposed. The experimental result shows that the infrared optical system can achieve good imaging quality over the temperature range from 0℃ to 60 ℃.

Abstract:Firstly, the synthesizable hardware description language (HDL) codes are generated in the design based on a simulink module by using the HDL Coder. Then, the FPGA is used to implement the dead pixel replacement in the image data stream of an infrared detector. By taking the dead pixel replacement of an uncooled infrared imaging system for example, the development process is described. Because the concerns are transferred to the upper design levels such as system architects and simulation, the development efficiency is improved and good image processing effectiveness is obtained.

Abstract:Taking the infrared images of water jet as the research object, a multistep denoising scheme for infrared images is proposed. Firstly, an image subtraction method is used to obtain the increment distribution of the infrared temperature field. Secondly, an adaptive median filter is used to remove the white noise with Gaussian distribution. Finally, a Gaussian high-pass filter is used to remove the periodical noise and sharpen the image. The experimental result shows that the proposed multistep denoising method is good in denoising. In the processed image, the structural characteristics of the jet core, main region, diffuse region and different turbulent jet in the turbulent flow composed of water mist and flowing air induced by the momentum exchange between the jet boundary and ambient air are revealed clearly. The analysis of the denoised infrared images helps us further understand the mechanism of turbulent jet. The scheme is of significance to the processing of similar infrared images, too.