Narrowband multichannel filters and integrated optical filter arrays

We propose and demonstrate three approaches to achieve narrowband multichannel filters. These are multiple heterostructures with defects, guided-mode resonance (GMR) Brewster filters with multiple channels, and integrated narrow bandpass filter arrays. Transmission studies for multiple heterostructures with defects are presented. We show that the enlargement of the forbidden band and multiple-channel filtering can be reached simultaneously with these configurations. GMR Brewster filters with multiple channels can be obtained with a single-layer grating. The same properties can be obtained by use of double-layer structures that consist of a homogeneous layer and a grating with equal refractive index. We developed a combinatorial etching technique that has 32 elements on a single substrate with which to fabricate integrated narrow bandpass filters. Single- and double-chamber integrated optical filter arrays were fabricated by use of this etching technique. These narrowband multichannel filters and narrow bandpass filter arrays show good filtering features and can be utilized in many optical applications.     

拖曳阵阵形估计的自适应Kalman滤波算法

柔性拖曳阵在水下拖动时受拖船拖动及海流等的扰动,因此拖曳阵的阵形估计问题是个存在未知输入的系统状态估计问题。文中采用了一个自适应的KALMAN滤波算法来解决这一问题。自适应Kalman滤波器包括两部分:一部分是没有输入的Kalman滤波,另一部分是自适应加权的Kalman滤波用于估计快时变的余量偏差。在迭代的每一步,均利用M-估计器和Huber函数相结合构造作为更新偏差函数的遗忘因子。数值仿真与海试结果表明,该方法比传统的状态估计方法估计效果好。     

Optimization algorithm for ultrabroadband multichannel aperiodic fiber Bragg grating filters

We consider an approach to designing complex multichannel filters for ultrabroadband applications. In contrast to earlier approaches that are restricted to specific problems, our generalized method can be applied to any conceivable fiber Bragg grating (FBG) multichannel design. Our method accommodates hundreds of filter channels that are spaced unevenly in wavelength, with variable widths, depths, and shapes. We demonstrate the power of the method for an FBG design with 150 narrow channels over the region 1400-1800 nm.     

A review of reduced Kalman filters for clock ensembles

This paper reviews the author's previous work on free-running timescales based on Kalman filters that act upon clock comparisons. The natural Kalman clock ensemble algorithm tends to optimize long-term timescale stability at the expense of short-term stability. By subjecting each postmeasurement error covariance matrix to a non-transparent reduction operation, one obtains corrected clocks with improved short-term stability and little sacrifice of long-term stability. A new result on covariance matrix reduction is also stated.     

Design and fabrication of multichannel Si/SiO2 autocloned photonic crystal edge filters

An Si/SiO2 multilayer with zigzag layer interfaces is fabricated on a patterned silica substrate using the autocloning method. The multilayer is designed to function as multichannel long-wave pass type edge filters with various cutoff wavelengths. A cutoff wavelength shift of the order of 190?nm in the near infrared region (1300-1500?nm) is experimentally demonstrated.     

非线性Kalman滤波器在纯方位被动跟踪中的应用

目标运动分析(简称TMA)是用于估计水下目标时变状态最主要的技术之一。应用了两种非线性滤波器——EKF和UKF来估计单/双基地情况下的目标运动状态,并由蒙特-卡洛仿真给出其跟踪性能。数值结果表明:在大部分情况下,特别是当目标存在机动时,UKF在估计精度和数值稳定性上都要好于EKF,其代价仅是少量地增加了的计算复杂度。     

Morphological processing of multichannel images

A theory for morphological processing of multichannel images within the abstract framework of lattice theory is presented. The theory makes use of marginal ordering and reduced ordering schemes to arrive at multivariate morphological operators. This paper elucidates the algebraic structure and properties of mathematical multivariate morphology. It is shown that matrix morphology formulation is a natural consequence of marginal ordering and serves as a technique for processing of multichannel images. Further, the concepts of quasi-ordering and complete quasi-lattices are introduced to define morphological operators utilizing the reduced ordering scheme.     

多通路高指向性声频声源的实验研究

1引言20世纪六十年代,Westervelt[1]和Berktay[2]先后提出了参量阵的概念,指出了两个频率的信号在非均匀介质中传播时可产生和频与差频信号。其中,     

Minicomputer-based supersensitive multichannel measuring system

Translated from Izmeritel'naya Tekhnika, No. 7, pp. 7–8, July, 1988.     

MTL代数的蕴涵滤子与正蕴涵滤子

在MTL代数M上引入了蕴涵滤子、正蕴涵滤子的概念,研究了它们的性质,给出了M的非空子集成为蕴涵滤子及正蕴涵滤子的充要条件和M的蕴涵滤子成为正蕴涵滤子的充要条件.讨论了蕴涵滤子与正蕴涵滤子的关系,得到了M的每一个正蕴涵滤子都是蕴涵滤子,但反之不真.     

Modified Kalman filter

This article presents a modification of Kalman filters for the problem of predicting random processes. It differs from modifiable-value filters in the use of constant coefficients in the corresponding expressions and the absence of a need for knowledge of the correlation function of the random signals subject to optimal filtration. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 13–15, May, 1996.