Infrared sensor signal generation method for direct signal injection simulation

摘要

Direct signal injection (DSI) simulation has been widely used in the performance testing and evaluation of an infrared imaging system (IRIS). A method to generate a high realism infrared sensor signal (HRIRSS) for DSI simulation is proposed. The IR sensor signal generation system hardware is based on a computer and field-programmable gate array processor. Mathematical models are adopted to quantitatively characterize the imaging physical effects (IPES) of the IRIS. Spatial template convolution and pixel processing approaches are used to realize high-speed real-time computation of the IPES. Taking advantages from low-noise circuit design methodologies, we designed a low-noise digital-analog converter to convert digital images generated by the system to analog signals for DSI simulation. The noise voltage of the converter within the passband is less than 244 μV, which ensures the system a 14-bit precision. For simulation of IR sensors with a resolution of 320 x 256 pixels, the processing speed is up to 240 frames per second (fps) and that for the 128 x 128 pixel sensor is 480 fps. The test results also show that the generated IR sensor signals have high confidence. In addition, the system has the advantages of simple structure, strong expansibility, low cost, and it has been used in practical applications.