脉冲测量雷达卫星标定方法研究

对脉冲测量雷达卫星标定方法的原理和工程应用等问题进行了研究,提出了标定模型和方法,分析了雷达跟踪能力和卫星定轨保障等工程应用问题,并对标定效果进行了仿真验证。     

ADS-B用于高精度雷达标定的方法

为了更好地解决高精度雷达标定的问题,提出了基于广播式自动相关监视系统(ADS-B)固定误差及目标回波中心动态修正的雷达标定新方法。首先分析了ADS-B位置数据误差的来源、类型及在雷达坐标系下的特征,同时对民航目标回波中心的变化作了分析建模,在此基础上进一步通过对雷达数据与ADS-B数据之差作动态联合修正,最终估算出雷达系统误差,提高了雷达系统误差标定的精度和稳定性。并利用多批次的实测数据对该标定新方法与其他方法进行了对比验证,结果表明,该方法有效提高了标定的精度和稳定性,并已成功应用于雷达标定设备中。     

一种角度夫塔标定的方法

本文探讨了一种无塔角度标定的方法，即在测量雷达上配装微光电视系统，利用伺服顶偏跟踪载标气球，通过建立微光电视脱靶量与雷达角误差电压及信息电平的函数关系，校准角误差通道。     

脉冲雷达卫星标定方法的一种工程实现研究

卫星标定是雷达靶场标定的新趋势。阐述了卫星标定的数学模型,给出了卫星标定实现的具体方法,包括卫星选择、数据预处理、数据融合准则和筛选准则,最后结合某雷达的实测数据进行了精度分析。结果表明通过卫星进行系统误差标定是可以实现的,标定结果可信,具有广阔的应用前景。     

一种角度无塔标定的方法

本文探讨了一种无塔角度标定的方法,即在测量雷达上配装微光电视系统,利用伺服顶偏跟踪载标气球,通过建立微光电视脱靶量与雷达角误差电压及信号电平的函数关系,校准角误差通道。     

GPS在雷达精度检飞中的应用

提出了用GPS 标定雷达检飞精度的要求,详细叙述了GPS检飞的理论基础和实验过程, 并给出GPS 雷达检飞的实验数据,结果表明GPS 可作为雷达检飞的标准设备。     

基于联合放球的船载雷达角度零值标校方法

船载雷达的角度零值是由坞内标校标定得到的,用于修正雷达角度系统误差,提高雷达测量精度。而在平时,当雷达角度零值发生变化时,如微光电视光轴发生变化,零位记忆装置发生故障,则无法用传统方法标校。本文提出的基于联合放球的雷达角度零值的标校方法,可不受坞内、校飞等特殊条件的限制,具有适用性广、精度高等优点。     

双月球近旁转向探月初步分析

分析了双月球近旁转向实现对月球多次探测的原理。基于圆锥曲线拼接法，建立了双月球近旁转向的简化数学模型．给出了一个初步分析算例，并与考虑精确动力学模型下的算例进行了比较。结果表明，该方法的结果同精确算例基本吻合，是一种有效的方法。     

机载光测设备单项误差的一种标定方法

提出了机载光测设备零位差与定向差的一种标定方法，论述了该方法的标定原理，给出了标定步骤，分析了该方法的标定精度，基本解决了机载吊仓式光测设备安装就位后单项差的标定问题。     

月球探测卫星的轨道支持

主要讨论采用月球卫星的探测方式时，月球探测器对测控系统的轨道支持要求和实现手段。重点对月球卫星转移轨道段的轨道测量和确定方法进行研究，利用仿真的地面站的测距和测角资料进行了定轨误差分析。     

基于轮地作用参数和PLSDA方法的月壤力学性能评估

为评估在轨月球车周边环境月壤力学性能,以月球车辙信息、轮上载荷和滑转率作为基本参数,提出了16个二元及三元标识量,结合偏最小二乘判别方法(PLSDA)建立评估月壤力学状态模型。根据容重对模拟月壤力学状态进行分级,分别为松软状态、自然状态和紧实状态。应用轮壤相互作用试验台共采集247组试验数据,每种模拟月壤状态的试验数据按照2:1比例随机划分为校正集样本和预测集样本,最终校正集和预测集样本个数分别为166和81个。考虑到原始数据值相差大和所提出部分标识量包含冗余信息的特点,因此在建立PLSDA模型时,应用均值中心化预处理方法对原始数据进行数据预处理,并优选10个标识量建立识别月壤力学状态的PLSDA模型,对应的校正集的准确率和预测集的准确率分别为90.96%和90.12%。结果表明,应用PLSDA方法并结合月球车的车辙信息、轮上载荷和滑转率以及优选标识量所建立的评估月壤力学状态判别模型,其计算快速准确,可用于月球车在轨评估车轮前方月壤的力学特性和通过性能评估。     

The Lunar Reconnaissance Orbiter Miniature Radio Frequency (Mini-RF) Technology Demonstration

The Miniature Radio Frequency (Mini-RF) system is manifested on the Lunar Reconnaissance Orbiter (LRO) as a technology demonstration and an extended mission science instrument. Mini-RF represents a significant step forward in spaceborne RF technology and architecture. It combines synthetic aperture radar (SAR) at two wavelengths (S-band and X-band) and two resolutions (150 m and 30 m) with interferometric and communications functionality in one lightweight (16 kg) package. Previous radar observations (Earth-based, and one bistatic data set from Clementine) of the permanently shadowed regions of the lunar poles seem to indicate areas of high circular polarization ratio (CPR) consistent with volume scattering from volatile deposits (e.g. water ice) buried at shallow (0.1–1 m) depth, but only at unfavorable viewing geometries, and with inconclusive results. The LRO Mini-RF utilizes new wideband hybrid polarization architecture to measure the Stokes parameters of the reflected signal. These data will help to differentiate “true” volumetric ice reflections from “false” returns due to angular surface regolith. Additional lunar science investigations (e.g. pyroclastic deposit characterization) will also be attempted during the LRO extended mission. LRO’s lunar operations will be contemporaneous with India’s Chandrayaan-1, which carries the Forerunner Mini-SAR (S-band wavelength and 150-m resolution), and bistatic radar (S-Band) measurements may be possible. On orbit calibration, procedures for LRO Mini-RF have been validated using Chandrayaan 1 and ground-based facilities (Arecibo and Greenbank Radio Observatories).     

Calibration of the MERIC full-polarimetric radar: theory and implementation

This paper describes the architecture and calibration design of the experimental ground based radar station MERIC. This full-polarimetric radar is conceived for the analysis and the recognition of non cooperative aircraft in flight.We carefully study how the full-polarimetric capability is obtained for a simultaneous transmit (simultaneous transmission of two linear FM with opposite slopes) radar system, using analogue deramping with a replica.The phase distortions of the signal propagating in the four polarimetric channels are carefully estimated. We define a phase calibrating method compatible with the outdoor measurements conditions and few constraints on reference targets.We show the phase accuracy obtained with the proposed calibration method on real measurements.     

The Lunar Radar Sounder (LRS) Onboard the KAGUYA (SELENE) Spacecraft

The Lunar Radar Sounder (LRS) onboard the KAGUYA (SELENE) spacecraft has successfully performed radar sounder observations of the lunar subsurface structures and passive observations of natural radio and plasma waves from the lunar orbit. After the transfer of the spacecraft into the final lunar orbit and antenna deployment, the operation of LRS started on October 29, 2007. Through the operation until June 10, 2009, 2363 hours worth of radar sounder data and 8961 hours worth of natural radio and plasma wave data have been obtained. It was revealed through radar sounder observations that there are distinct reflectors at a depth of several hundred meters in the nearside maria, which are inferred to be buried regolith layers covered by a basalt layer with a thickness of several hundred meters. Radar sounder data were obtained not only in the nearside maria but also in other regions such as the farside highland region and polar region. LRS also performed passive observations of natural plasma waves associated with interaction processes between the solar wind plasma and the moon, and the natural waves from the Earth, the sun, and Jupiter. Natural radio waves such as auroral kilometric radiation (AKR) with interference patterns caused by the lunar surface reflections, and Jovian hectometric (HOM) emissions were detected. Intense electrostatic plasma waves around 20 kHz were almost always observed at local electron plasma frequency in the solar wind, and the electron density profile, including the lunar wake boundary, was derived along the spacecraft trajectory. Broadband noises below several kHz were frequently observed in the dayside and wake boundary of the moon and it was found that a portion of them consist of bipolar pulses. The datasets obtained by LRS will make contributions for studies on the lunar geology and physical processes of natural radio and plasma wave generation and propagation.     

嫦娥三号着陆器统计定位精度分析

“嫦娥三号”将在月球放置着陆器,实现月面软着陆,因此,需要对着陆器进行精确定位.本文简述了月球着陆器的统计定位方法与协方差分析理论,分析了影响统计定位精度的主要误差源.基于现有测控条件,从跟踪弧段和测量数据组合2个方面,对“嫦娥三号”着陆器的定位精度进行了分析.针对短弧条件下单站测距数据定位不稳键的问题,提出了结合月面高程约束的定位方法.协方差分析结果表明：高程数据的使用可以实现单站30 min测距优于1 km的定位精度;当观测数据累积至3d时,单站测量与VLBI（Very Long Baseline Interferometry,甚长基线干涉测量）的不同组合可以实现同等量级、优于百m的定位精度;测量系统差是制约定位精度的主要因素,完全标校测量的系统偏差则能实现10 m左右的定位精度.     

一种宽带阵列幅相与互耦误差联合校正算法

宽带数字阵列雷达接收通道中存在随频率变化的幅相误差和互耦误差,会严重影响雷达性能。针对这一问题,提出了一种宽带数字阵列幅相与互耦误差联合校正算法。首先选取通带内多个离散频点,对于每个频点,将幅相误差和互耦误差作为一个整体,采用基于子空间原理的窄带校正算法估计其阵列失真参数,并计算校正矩阵;然后将其组合起来,构成频域离散校正矩阵;最后基于最小二乘准则,设计了宽带有限长脉冲响应(FIR)校正滤波器矩阵。利用该矩阵,可实现通带范围内任意带宽入射信号的校正。计算机仿真实验验证了该算法的有效性。对实测数据的处理结果表明该算法在宽带数字阵列雷达系统中具有实用价值。     

频率捷变雷达信号源实时动态频率校准方法

分析了频率捷变雷达信号源边跟踪边校准方法存在的缺陷,提出了一种新型实时动态频率校准方法,在信号源边跟踪边校准工作模式上,进一步提高了信号源的频率跟踪精度和稳定工作时间,并大大减小了漏跟概率.     

基于DRFM技术的雷达标校器设计与实现

建立了基于数字射频存储器技术构建雷达标校器的方法.该雷达标校器可灵活实现目标运动模拟、多普勒频率加载、目标RCS模拟、多目标模拟等功能,较传统的基于光纤延迟实现的雷达标校器更具有应用价值.针对实际应用需求提出了解决频率捷变的方案,给出了典型模拟策略所需数学模型.应用研究表明,基于数字射频存储器技术的雷达标校器具有较强的...