For spaceborne SAR system with large squint angle, the main error source of classical range-Doppler algorithm is analyzed which causes the loss in image quality. 分析了当天线斜视角增大时,导致传统距离-多普勒成像算法性能下降的主要误差来源。
Imaging Algorithm Research of Bistatic SAR Based on GPS under Large Squint Angle 基于GPS的双基地SAR大斜视角成像算法研究
Correlation factor for the squint angle more than that before wearing redressing mirror of myopia with concomitant exotropia 近视伴共同性外斜视戴矫正镜后斜视角大于矫正前的相关因素研究
It is proved that the choice of the reference frequency in NCSA is unique. A multiple-look SAR imaging method for the large squint angle is presented. 指出了非线性CS算法在实际应用中其参考频率的选择是唯一的,并提出了一种在大斜视角下进行多视处理的方法。
These conclusions are important for choosing suitable radar system parameters such as center frequency, resolution and imaging squint angle in engineering design. 这些结论对工程设计牛选择合适的工作参数,如载频、分辨率、成像斜角等具有较为重要的参考价值。
With the linear R-D algorithm and the proposed motion compensation method, airborne squint-looking SAR patch-mapping has been implemented successfully in a campaign. And an X-band SAR image of mountainous area of 40 degree squint angle is presented at the end of this paper. 用上述运动补偿方法和线性R-D成像算法,某型机载SAR在试飞实验中成功实现了斜视区域成像。
A Wavenumber Domain Algorithm for Spaceborne Bistatic SAR Imaging with Large Squint Angle 适于大斜视角的星载双基地SAR波数域成像算法
Finally it makes the simulation. The simulation results show that the range motion error is the most fact affecting the SAR geolocation accuracy, which also related to the squint angle and the velocity. 仿真结果表明:距离向速度误差是影响SAR定位精度的主要因素,定位精度还与斜视角和飞行速度有关。
Signal properties of spaceborne spotlight SAR were discussed. The relationships of centroid Doppler, Doppler bandwidth and PRF ( Pluse Repetition Frequency) with squint angle were analyzed. 分析了星载聚束式合成孔径雷达(SAR)的信号特性,主要研究了多普勒中心频率、多普勒带宽以及脉冲重复频率(PRF)与斜视角的关系。
The scanning angular scope is mainly determined by the azimuth width of the terrain patch, nominal slant range, squint angle, platform velocity, and azimuth beam width. 天线扫描角度范围由要求的成像区方位宽度、斜距、斜视角、载机速度和波束方位宽度决定。
Based on the fact that the Doppler centroid and the squint angle are directly related, this paper proposes a Doppler centroid estimation technique by using Radon transform. 基于多普勒中心与斜视角直接相关的事实,提出了一种使用Radon变换估计多普勒中心的方法。
The quality of images of simulated bistatic echoes focused by the algorithm is much better than algorithm based on two-order range model at the case of large squint angle and high resolution. 最后对仿真点目标双基地回波进行成像处理,结果与基于二阶距离模型的成像算法相比较,证明了本文等效距离模型和成像算法的优越性。
RD algorithm based on minimum entropy criteria carries out the correction phase errors caused by high squint angle via searching error coefficients for improving the imaging focus effect. 基于最小熵准则的自聚焦RD算法在一般RD算法的基础上引入最小熵准则来补偿由于大斜视角引起的相位误差,改善图像聚焦效果。
With the analysis of R-D algorithm, the relationship between the frequency of radar, the signal frequency width and the squint angle is deduced. The result is identified by computer simulation. 该文通过对R-D成像方法的分析,推导了在R-D成像方法下雷达工作频率,信号带宽与成像角之间的关系,并用计算机仿真进行了验证。
The air-to-air missile borne SAR has important characteristics including high flight speed with non-constant velocity and big squint angle, which forward a greater requirements for the real-time performance, motion precise compensation. 空空导弹弹载SAR平台的大斜视角和大机动特点对成像算法的实时性、运动补偿提出了更高的要求。
The simulation results prove that roll error and its stabilization and spaceborne SAR squint angle are the key factors to SAR resolution performance errors. The conclusion is valuable to determine and optimize the satellite system parameters. 分析仿真结果表明,滚动向指向误差和稳定度以及星载SAR中心视角对分辨特性影响较大,该研究结果对于卫星总体参数确定和优化设计具有参考价值。
Correction of angle of squint: Angle of squint decreased by simple weaken the rectus muscles was least, and decreased by combined with weaken resection reposition the rectus was best. 斜视矫正量:以单纯直肌减弱术矫正量最小,直肌减弱联合缩短再复位术矫正量最大。
Computer simulation of simulated data, the result shows that NCS algorithm based on motion compensation is effective on SAR echo data with high squint angle. 对大斜视角模拟数据进行成像仿真,仿真结果表明,基于运动补偿的非线性CS(NCS)算法对大斜视角数据的有效性。
The main works includes: ( 1) the spectrum folding problem encountered in squinted spotlight SAR case is analyzed, and the reason of the squint angle has impact on the azimuth coarse focusing is found out. 具体工作为:(1)深入分析了斜视聚束SAR的方位谱混叠现象,找出了斜视角影响方位粗聚焦的根本原因。