环境一号卫星CCD相机相对定标数据处理

文章简要介绍了环境一号卫星CCD相机相对定标实验,分析了归一化系数法、两点法、最小二乘法的数学原理,然后运用分段归一化系数法、分段两点法、分段最小二乘法求取像元归一化系数,并进行了误差分析。     

一种新的闭路制导导引方法

闭路制导方法是一种实用的方法误差比较小的制导方法。其中,如何将实际速度导引到需要速度至关重要,通常的闭路制导导引方法在关机点附近不稳定,会产生一定的方法误差。为了避免这种导引不稳定的影响,本文给出了一种采用目标瞬时方位角为基准的新型闭路制导导引方法。通过仿真计算,证明该方法关机点附近导引稳定,导引引起的方法误差较小。     

低RCS的双层缝隙阵FSS雷达天线罩的设计与分析

文章采用谱域法并结合互阻抗法,对低RCS双层FSS天线罩进行了仿真设计,并就多层介质衬底影响下的频率特性进行了分析。与其他方法相比,谱域法能仿真更复杂的FSS单元,求解模型简单,计算量小,能得出非常理想的仿真结果。文章采用这种方法得到的分析结果与实测结果相符合。     

FY-2卫星扫描辐射仪在轨定标方法

ＦＹ－ ２ 在轨定标是云图定量处理的关键。首先叙述了ＦＹ－ ２ 可见光、红外和水汽通道的定标方法;然后介绍了星上各通道的电定标及黑体定标的过程。结果表明红外通道在轨定标曲线与实验室定标非常接近。     

微小卫星数据存储器单粒子作用的检测及纠错

因为辐射导致的单粒子翻转效应（SEU）,使得微小卫星星上存储器在太空运行时其内容可能出现小概率错误,这种错误会影响计算机系统的运行和关键数据。文章阐述了“清华一号”微小卫星数据处理系统对SEU的纠错方法,分别介绍了实现（12,8）和（39,32）的汉明码纠错设计和基于FPGA的三模块冗余纠错编码方法,并分析了这些方法的工作原理和过程。     

利用GPS对地球静止轨道卫星定轨的可行性

总结了几种利用 GPS对地球静止轨道卫星定轨的方法 ,并且对仅仅接收 GPS星发射的信号来定轨这种方法进行了计算论证。得出了 GPS星在一个计算周期 (2 4 h)内对于静止卫星的可利用性 ,比较了不同条件下的可利用性。通过对可利用性分析 ,提出了一种利用 GPS对静止卫星定轨的方法     

Moving scanning emitter tracking by a single observer using time of interception: Observability analysis and algorithm

The target motion analysis (TMA) for a moving scanning emitter with known fixed scan rate by a single observer using the time of interception (TOI) measurements only is investigated in this paper.By transforming the TOI of multiple scan cycles into the direction difference of arrival (DDOA) model,the observability analysis for the TMA problem is performed.Some necessary conditions for uniquely identifying the scanning emitter trajectory are obtained.This paper also proposes a weighted instrumental variable (WIV) estimator for the scanning emitter TMA,which does not require any initial solution guess and is closed-form and computationally attractive.More importantly,simulations show that the proposed algorithm can provide estimation mean square error close to the Cramer-Rao lower bound (CRLB) at moderate noise levels with significantly lower estimation bias than the conventional pseudo-linear least square (PLS) estimator.     

数据链作战使用性能试验方法研究

分析了数据链在现代战争中的重要作用,提出了表征数据链作战使用性能的指标体系、试验数据链作战使用性能的试验方法以及试验数据录取方法,并给出了相应的试验数据处理方法。     

Unstable unsteady aerodynamic modeling based on least squares support vector machines with general excitation

Common, unsteady aerodynamic modeling methods usually use wind tunnel test data from forced vibration tests to predict stable hysteresis loop. However, these methods ignore the initial unstable process of entering the hysteresis loop that exists in the actual maneuvering process of the aircraft. Here, an excitation input suitable for nonlinear system identification is introduced to model unsteady aerodynamic forces with any motion in the amplitude and frequency ranges based on the Least Squares Support Vector Machines (LS-SVMs). In the selection of the input form, avoiding the use of reduced frequency as a parameter makes the model more universal. After model training is completed, the method is applied to predict the lift coefficient, drag coefficient and pitching moment coefficient of the RAE2822 airfoil, in sine and sweep motions under the conditions of plunging and pitching at Mach number 0.8. The predicted results of the initial unstable process and the final stable process are in close agreement with the Computational Fluid Dynamics (CFD) data, demonstrating the feasibility of the model for nonlinear unsteady aerodynamics modeling and the effectiveness of the input design approach.     

AUSM+方法在 粘性内流模拟中的应用

本文阐述了三维RANS方程求解程序中使用的AUSM+离散方法以及Spalart-Allmaras湍流模型，然后对两个算例—Sajben收缩扩散通道内跨声速流动和NASA TP-3252文献中给出的透平静叶排内部流动，进行了数值模拟，并把数值结果与实验结果进行了比较，说明三维RANS方程求解程序可以准确模拟复杂的内部流场。