The suppression of aero-optical aberration of conformal dome by wavefront coding

The aircraft target in the airport and its ground background are significant in military applications. In order to employthe algorithms for the detection, identification and dynamic monitoring, a software which can complete infrared radiation simulation of aircraft/ground object in airports under conditions of different seasons, different meteorological conditions, different periods and different detecting bands is needed to provide training samples. This paper utilizes OpenGL to construct a model of the aircraft target in the airport and the ground object in Visual Studio2010. Combined withthe theoryof heat transfer and infrared radiation, this study embeds the RadThermIR software used for thermal infrared analysis and proposes infrared image simulation. Then we calculate the infrared radiation field model of the aircraft and its ground object. Choosingimage gray similarity as the evaluation metric, the infrared image simulation precision of this method is over 80%. Experiment results indicate thatour proposed method can provide training samples with analysis data of rich infrared characteristics and featured knowledge for the automatic detection and identification of aircraft targets in the all-weather airport.

An Infrared Radiation Simulation Method for Aircraft Target and Typical Ground Objects Based on RadThermIR and OpenGL

This paper is based on the researching work of MW KGC04 IR thermal imagerThree main kinds of noises has been submitted and deeply analyzed during the development process,they are the noise on the signal transportation network,the noise of the bias voltage and the noise of the signal processing Op amplifierCombing with the key performance indicators of the MW KGC04 and the analysis of the noise model of each kinds of them which just mentioned above,the noise source of the driving circuit has been studied,and finally proposed very efficient and effective ways to lower all kinds of themThe methods in this paper have been used in designing and manufacturing the 640×512 thermal imager,and have received desired results

The Noise Analysis and Inhibition Technology of the Driving Circuits of the 640×512 IR Focal Plane Detector

The work presented in this paper focuses on real-time simulation of the airborne forward looking infrared (FLIR) sensor typically configured by modern helicopter. Based on infrared radiation theoretic model, the infrared transmittance model of “target-background-atmosphere-imaging system” is established. Furthermore, using modern computer graphics hardware, the detection signal is output in real time through the interacting of the virtual environment, which is the working process of sensors in actual infrared system. Simulation results shows that the platform can dynamically and efficiently generate realistic infrared images of helicopter varying with different simulation parameters. The dynamic simulation of large scale infrared scene can enhance the situational awareness for pilot.

Real-time simulation of airborne FLIR sensor

Normal Distribution Transform (NDT) algorithm plays the role of detecting the relative pose of the vehicle in high-precision map. In this paper, a method of setting downsampling factor and grid factor for NDT relocation algorithm in dynamic environment is proposed, which can solve the problems of excessive NDT relocation error and location loss caused by dynamic objects accounting for 1 % to 35 % of the volume of scanning point cloud in vehicle environment. To simulate a real dynamic point cloud environment, the single-frame LiDAR point cloud space is voxelized into a mesh. Each grid is assigned a random number evenly distributed between 0 and 1. The threshold value for whether to add a Gaussian noise point is also set. Seven representative dynamic objects on the highway are selected. The threshold value of probability distribution function of Gaussian noise object needs to be set. Then the volume content of the dynamic object in the single frame point cloud space is calculated according to the set threshold value by using the definite integral. By changing the content and volume of dynamic obstacles in a dynamic environment, the effects of the downsampling factor and the grid factor on the accuracy of the repositioning trajectory are obtained. The resampling and mesh coefficients are optimized based on the analysis of the repositioning trajectory accuracy. The results show that When the current sampling factor is fixed, the grid factor of the NDT algorithm is proportional to the RMSE factor. When the NDT grid factor is fixed and the down sampling factor is equal to the side length of the obstacle, the NDT relocation accuracy is the highest and reaches the local optimum. 

Setting Method of Downsampling Factor and Grid Factor for NDT Relocation Algorithm in Dynamic Environment

Simulation of IR detector noise is a difficult part in engineering development of 3D dynamic IR scene simulation A technology of dynamically generating noise of IR detector is provided in this article First, by computing and analyzing the images sequence of IR detector, the random gauss noise, salt noise and heterogeneity noise is picked up In scene simulation developed by OSG, a noise "screen" is attached to the view of the simulation scene by technology of refer to texture (RTT), and the image of the heterogeneity noise is made as the RTT texture To realize the dynamic effect, the random gauss noise is generated and rendered by shader base on GPU The salt noise is directly rendered according to the sign of blind pixels in RTT texture The experiment shows that the noise simulated by technology in this article is lifelike, and the system cost of the technology is little The method in this paper provides a practical engineering train of thought for development of dynamic 3D IR scene

Xiaofang Xie

Papers

Dynamic Simulation of Noise in 3D Infrared Scene Simulation