GPS时差数据卡尔曼滤波器

利用卡尔曼滤波技术对GPS定时校频数据进行处理提高精度,是国际上近几年的最新研究课题。全面的介绍了北京无线电计量测试研究所开展该项技术的研究成果,从基本理论,滤波器模型选定、滤波器设计、仿真试验分析等方面作了论述,并给出实际应用的实验结果。对国内开发应用该技术具有参考价值。     

自动相关监视系统的研究与开发

介绍了自动相关监视系统的基本概念，构成原理和与实施相关的研究与开发工作，特别是重点介绍了以ＰＣ机为基础的ＡＤＳ信息处理系统的成果，最后还介绍了ＡＤＳ运行情况。     

机载目标状态估计器

研究基于空载雷达测量下的机动目标状态估计器的设计问题。通过建立直角坐标状态方程和选取一种伪测量量，并采用测量模型线性化的方法，建立起了估计器的基本结构，在此基础上增加距离通道的冗余滤波，进一步提高距离通道的估计精度，最后将估计器联入整个综合火力／飞行控制系统中，进行了Ｍｏｎｔｅ Ｃａｒｌｏ仿真，仿真结果表明，设计的目标状态估计器具有很好的跟踪估计性能。     

杂波环境下的机动目标检测和跟踪算法

交互多模式(IMM)是一种有效的机动目标跟踪算法,但由于其要求具有很多的先验前提条件而不利于工程实现.研究了一种杂波环境下更适合于工程实现的机动目标(同样适用非机动目标)的跟踪算法,该算法通过一种由测量位置估计误差决定的机动检测函数来实现杂波背景中的机动目标检测,并通过改变Kalman滤波的相关参数,实现自适应跟踪.该算法克服了IMM算法的模式限制和复杂性,同时也避免了对非机动目标的跟踪中,在跟踪模式间相互切换时所换造成的影响.通过在空管系统(ATC)的大量模拟实验,验证了该算法的有效性和重大应用价值.     

惯性/图像组合导航中的双模态双滤波器研究

在简要介绍了飞行器视觉图像定位导航原理及模型的基础上，针对其非线性模型的推广Kalman滤波的收敛与初始条件有关的问题，将其定位导航的两种模型（线性与非线性模型）组合，提出了双模态双滤波器滤波方法。这种滤波能很好地解决非线性推广Kalman滤波的收敛问题。通过第一个线性滤波器的滤波估计给第二个非线性滤波器提供滤波初值，使这一非线性滤波收敛，并能取得较高的滤波精度。     

短波信道多普勒扩展仿真与实现

针对直接FIR滤波和多级内插滤波生成衰落因子的算法中存在算法复杂度高、计算效率低、存储空间大等问题,文章研究了一种多级迭代滤波的算法,以降低算法复杂度和减少存储空间,实时生成衰落因子;并进行了算法的复杂度分析和仿真实现,验证了算法的有效性.     

简化七阶CQKF及其在SINS大失准角初始对准中的应用

针对捷联惯性导航系统（SINS）大失准角初始对准的滤波过程，提出简化七阶正交容积卡尔曼滤波算法（7th-SCQKF）。根据简化容积卡尔曼滤波(CKF)理论，推导出改进的简化七阶CKF算法（7th-MSSRCKF），改进了原简化七阶CKF（7th-SSRCKF）的性能；同时，在7th-SSRCKF和7th-MSSRCKF基础上，引入正交半径准则，提出简化七阶CQKF（7th-SCQKF）算法，提高了滤波精度；并将简化七阶CQKF（7th-SCQKF）算法应用到SINS的大失准角初始对准仿真中，结果表明，7th-SCQKF比7th-MSSRCKF的滤波精度高，验证了新算法的正确性和有效性。     

Kalman filter based estimation of differential hardware biases with triangular interpolation technique for IRNSS

Ionosphere delay correction is the main error correction to the computation of single frequency user position using satellite navigation. However ionosphere delay consists of not only delay but also frequency dependent differential hardware biases from satellite and receiver ends. For ionosphere point of view, Indian Regional Navigation Satellite System (IRNSS) service area comes in equatorial anomaly region. It is a unique satellite navigation system which operates at L5 and S frequencies and consists of Geostationary Earth Orbit (GEO) and Geo Synchronous Orbit (GSO) satellite constellation. With IRNSS measurements availability, there is a good opportunity to estimate and analyse differential hardware biases with GEO/GSO combination and with equatorial ionosphere variation. In this paper, Kalman filter based estimation with triangular interpolation technique is used to estimate differential hardware biases for all IRNSS satellites and reference receivers at L5 frequency. The standard deviation of the 15?days of daily estimation of satellite differential hardware biases is in the range of 0.32 to 1.17 TECU for all IRNSS satellites. Similarly, the standard deviation of the 15?days of daily estimation varies up to 2.85 and 6.0 TECU for receiver differential hardware biases during calm and stormy period respectively. The ionosphere delay computed using estimated differential hardware biases is compared with Global Ionosphere Map (GIM) data. A rigorous analysis is carried out to study the error in the estimation in terms of input data noise level, satellite constellation and effect of latitude. Our result reveals that over IRNSS service area, there is an exponential increase in the error in the estimation of receiver differential hardware biases with respect to latitude.     

The Western Crete geodetic infrastructure: Long-range power-law correlations in GPS time series using Detrended Fluctuation Analysis

The Global Positioning System makes it possible, nowadays, to measure crustal displacements with unprecedented accuracy. These measurements can improve our understanding of the spatio-temporal evolution of motion along tectonic plate boundaries, as well as deepen our comprehension for the nature of earthquake fault behavior and earthquake cycle. The Hellenic subduction zone and the earthquake-prone Crete, with large crustal motions of 3–4 cm/yr, may provide such a natural laboratory for this type of investigation. In this work, we examine the statistical structure and behavior of time series, as produced by permanent GPS sites, established on the islands of Crete and Gavdos.     

低成本IMU／GPS组合导航系统研究

ＧＰＳ／ＩＮＳ组合导航系统已在一定领域得到应用，而ＩＮＳ昂贵的价格限制了它的广泛应用，本文采用低成本惯性测量组件（ＩＭＵ）设计了低成本ＩＭＵ／ＧＰＳ组合系统的硬件和相应的软件，进行了静态实验和数据处理，系统的俯仰角和横滚角误差均小于０．２°，实验结果表明，低成本组合系统的性能较好，而其性能价格比更高。