海杂波是影响雷达对海工作的重要因素,海杂波的精确建模与仿真是实现雷达性能检测,以及算法优化的先决条件。在分析海杂波幅度分布特性、时间和空间相关特性的前提下,利用Cholesky分解并结合球不变随机过程法(SIRP,spherically invarian...海杂波是影响雷达对海工作的重要因素,海杂波的精确建模与仿真是实现雷达性能检测,以及算法优化的先决条件。在分析海杂波幅度分布特性、时间和空间相关特性的前提下,利用Cholesky分解并结合球不变随机过程法(SIRP,spherically invariant random processes),提出了一种用于生成时空二维相干相关K分布海杂波的仿真模型,仿真结果表明该方法能够生成满足时间和空间相关特性要求的二维海杂波,得到的数据可以直接作为雷达目标模拟器中的输入信号。展开更多
A multi-scale narrow band correlated-k distribution（MSNBCK） model is developed to simulate infrared radiation（IR） from an exhaust system of a typical aircraft engine.In this model,an approximate approach instead o...A multi-scale narrow band correlated-k distribution（MSNBCK） model is developed to simulate infrared radiation（IR） from an exhaust system of a typical aircraft engine.In this model,an approximate approach instead of statistically uncorrelated assumption is used to treat overlapping bands in gas mixture.It significantly reduces the requirement for computing power through converting the exponential increase of computing power consumption with the increase of participating gas species to linear increase.Besides,MSNBCK model has a great advantage compared with conventional methods which can estimate each species＇ contribution to the total gas mixture radiation intensity.Line by line（LBL） results,experimental data and other results in the references are used to evaluate this new model,which demonstrates its advantage in terms of accuracy and computing efficiency.By coupling this model and finite volume method（FVM） into radiative transfer equation（RTE）,a comparative study is conducted to simulate IR signature from the exhaust system.The results indicate that wall＇s IR emission should be considered in both 3-5 μm and8-14 μm bands while gases＇ IR emission plays an important role only in 3-5 μm band.For plume IR radiation,carbon dioxide＇s emission is much more significant than that of water vapor in both3-5μm and 8-14 μm bands.Especially in 3-5 μm band,the water vapor＇s IR signal can even be neglected compared with that of carbon dioxide.展开更多
文摘海杂波是影响雷达对海工作的重要因素,海杂波的精确建模与仿真是实现雷达性能检测,以及算法优化的先决条件。在分析海杂波幅度分布特性、时间和空间相关特性的前提下,利用Cholesky分解并结合球不变随机过程法(SIRP,spherically invariant random processes),提出了一种用于生成时空二维相干相关K分布海杂波的仿真模型,仿真结果表明该方法能够生成满足时间和空间相关特性要求的二维海杂波,得到的数据可以直接作为雷达目标模拟器中的输入信号。
文摘A multi-scale narrow band correlated-k distribution（MSNBCK） model is developed to simulate infrared radiation（IR） from an exhaust system of a typical aircraft engine.In this model,an approximate approach instead of statistically uncorrelated assumption is used to treat overlapping bands in gas mixture.It significantly reduces the requirement for computing power through converting the exponential increase of computing power consumption with the increase of participating gas species to linear increase.Besides,MSNBCK model has a great advantage compared with conventional methods which can estimate each species＇ contribution to the total gas mixture radiation intensity.Line by line（LBL） results,experimental data and other results in the references are used to evaluate this new model,which demonstrates its advantage in terms of accuracy and computing efficiency.By coupling this model and finite volume method（FVM） into radiative transfer equation（RTE）,a comparative study is conducted to simulate IR signature from the exhaust system.The results indicate that wall＇s IR emission should be considered in both 3-5 μm and8-14 μm bands while gases＇ IR emission plays an important role only in 3-5 μm band.For plume IR radiation,carbon dioxide＇s emission is much more significant than that of water vapor in both3-5μm and 8-14 μm bands.Especially in 3-5 μm band,the water vapor＇s IR signal can even be neglected compared with that of carbon dioxide.
