A New Echeloned Poisson Series Processor (EPSP)

A specialized Echeloned Poisson Series Processor (EPSP) is proposed. It is a typical software for the implementation of analytical algorithms of Celestial Mechanics. EPSP is designed for manipulating long polynomial-trigonometric series with literal divisors. The coefficients of these echeloned series are the rational or floating-point numbers. The Keplerian processor and analytical generator of special celestial mechanics functions based on the EPSP are also developed.     

Mechanized Algebraic Operations (MAO)

A software package for Mechanized Algebraic Operations (MAO) is described. With MAO one is able to manipulate on the computer Poisson series in literal form. The system is operational; it has application in the fields of celestial mechanics, astrodynamics, and nonlinear mechanics. Besides describing the system, the present paper suggests various techniques to prepare problems such that they lend themselves for an automated treatment with MAO. Optimized implementation of the general subroutines is discussed.     

Software tools for nonlinear dynamics

An algebraic processor plus an interactive graphics system transform a desk computer into a very handy tool for research in non linear mechanics.     

Application of a massively parallel computer to the N-body problem

Parallel processor computers represent a new technology that has recently become available for astronomical applications. We have implemented an N-body code on a TMC Connection Machine CM-2 in order to investigate the advantages of a massively parallel computer over serial machines, including conventional supercomputers. For collisionless problems following N stars, a direct integration code scales as O(N²) on serial machines and on the CM-2 as O(log(N)) for small N and O(N log(N)) for large N. The CM-2 outperforms workstations for N>50 and supercomputers for N>4000.     

The Fresnel imager: instrument numerical model

The methodology used in the end-to-end numerical model of the Fresnel Interferometric Imager is presented. This Instrument Numerical Model (INM) performs plane-to-plane Fresnel propagation, starting from the Fresnel array and ending at the achromatic focal plane, and has been written in c so that it can handle various instrument configurations (sizes of Fresnel arrays from cm to m, from a few Fresnel zones to a few hundred, and for various wavelengths) with a standard desktop computer (a few GHz processor(s) speed, a few GB of memory, execution time per wavelength spanning from few minutes to few hours in the most extreme cases). The INM is used to estimate the performances of the Fresnel Imager: angular resolution, photometric dynamic range, transmission, for on and off-axis sources.     

The lunar theory of Hill and Brown

Hill and Brown solved the equations of motions of the Moon with the help of multiple Fourier series. We describe their method and show how it can be adapted, so that all work can be carried out by a computer with the help of an algebraic processor called POLYPAK.Proceedings of the Sixth Conference on Mathematical Methods in Celestial Mechanics held at Oberwolfach (West Germany) from 14 to 19 August, 1978.This research was partially supported under the National Science Foundation grant MCS 78-01425.     

An iterative method of general perturbations programmed for a computer

Hansen's classical method of general perturbations was revised from its basis on a Taylor Series expansion in the masses of the disturbing planets to an iterative method, which can start with the best theory known, or with only the mean, or osculating, orbit of the planet. The article describes the iterative Hansen's method together with some of the necessary subroutines which have been programmed to handle the series on a digital computer.The method has been tested by generating the theory of a major planet and the theory of a minor planet having a near commensurability with Jupiter and some of the results have been described in the last section of the paper.This paper is a summary of dissertation presented to the University of Cincinnati in candidacy for the degree of Doctor of Philosophy.     

Determination of velocities of East European stations from GNSS observations at the GNSS data analysis center of the main astronomical observatory,national academy of sciences of Ukraine

Dynamics of horizontal and vertical motions of East European GNSS stations has been studied at the GNSS Data Analysis Center, Main Astronomical Observatory, National Academy of Sciences of Ukraine (MAO NASU). The GNSS station coordinates have been estimated from regional processing and reprocessing performed with the Bernese GNSS Software ver. 5.2 at the GNSS Data Analysis Center, MAO NASU. The velocity values have been computed for 42 GNSS stations, 15 of them located in Ukraine. Global and local offsets of the horizontal and vertical motions of the GNSS stations have been determined.     

A digital signal pre-processor for pulsar search

A fast digital signal processor has been designed and built for survey and some observations of pulsars. The processor obtains spectral information over a bandwidth of 16 MHz (256 channels) every 25μsecs Wedescribethe design ofthisprocessor and present some test observations made with the Ooty Radio Telescope.     

A New Symbolic Processor for the Earth Rotation Theory

In this paper we present a new symbolic processor specially suited for the Earth rotation theory. This processor works with a more general kind of Poisson series called Kinoshita series, which has resulted to be very useful in the Earth rotation theory. Its structure is adapted for dealing with the more general analytical expressions that appear in the Earth rotation theory. This new algebraic processor has been successfully used for computing different contributions to the nutation series of the rigid Earth.This revised version was published online in October 2005 with corrections to the Cover Date.     

一种基于RTAI实时操作系统的相关跟踪处理机

引入倾斜校正自适应光学技术到月球激光测距中,详细介绍了倾斜校正自适应光学的相关跟踪原理,给出了一种基于实时操作系统RTAI的相关跟踪波前处理机的设计结果.该波前处理机采用绝对差分算法,使用通用CPU,基于Linux硬实时扩展系统BTAI实现对波前的实时处理.实验结果证明,它的相关跟踪处理帧频为1 KHz,并且具有集成度...     

AQUAdexIM: highly efficient in-memory indexing and querying of astronomy time series images

Astronomy has always been, and will continue to be, a data-based science, and astronomers nowadays are faced with increasingly massive datasets, one key problem of which is to efficiently retrieve the desired cup of data from the ocean. AQUAdexIM, an innovative spatial indexing and querying method, performs highly efficient on-the-fly queries under users’ request to search for Time Series Images from existing observation data on the server side and only return the desired FITS images to users, so users no longer need to download entire datasets to their local machines, which will only become more and more impractical as the data size keeps increasing. Moreover, AQUAdexIM manages to keep a very low storage space overhead and its specially designed in-memory index structure enables it to search for Time Series Images of a given area of the sky 10 times faster than using Redis, a state-of-the-art in-memory database.     

A note on an attempt at more efficient Poisson series evaluation

Eliminating many of the trigonometric function calls by a suitable series transformation has resulted in a substantial reduction of on-line computing time while very long Poisson series are being evaluated. A further reduction has been realized by applying a short SNOBOL processor to the FORTRAN coding of the transformed series which eliminates many of the multiplication operations during the course of series evaluation.     

Real-time signal processor for pulsar studies

This paper describes the design, tests and preliminary results of a real-time parallel signal processor built to aid a wide variety of pulsar observations. The signal processor reduces the distortions caused by the effects of dispersion, Faraday rotation, doppler acceleration and parallactic angle variations, at a sustained data rate of 32 Msamples/sec. It also folds the pulses coherently over the period and integrates adjacent samples in time and frequency to enhance the signal-to-noise ratio. The resulting data are recorded for further off-line analysis of the characteristics of pulsars and the intervening medium. The signal processing for analysis of pulsar signals is quite complex, imposing the need for a high computational throughput, typically of the order of a Giga operations per second (GOPS). Conventionally, the high computational demand restricts the flexibility to handle only a few types of pulsar observations. This instrument is designed to handle a wide variety of Pulsar observations with the Giant Metre Wave Radio Telescope (GMRT), and is flexible enough to be used in many other high-speed, signal processing applications. The technology used includes field-programmable-gate-array(FPGA) based data/code routing interfaces, PC-AT based control, diagnostics and data acquisition, digital signal processor (DSP) chip based parallel processing nodes and C language based control software and DSP-assembly programs for signal processing. The architecture and the software implementation of the parallel processor are fine-tuned to realize about 60 MOPS per DSP node and a multiple-instruction-multiple-data (MIMD) capability.     

利用单片机与CPLD技术控制PCI网卡

简单介绍了PCI总线协议以及PCI接口原理。给出了一种利用单片机与复杂可编程逻辑器件CPLD(complex programmable logic device)控制PCI网卡,实现以太网通信的方案设计。重点说明了如何使用CPLD芯片设计单片机与PCI网卡之间的PCI接口。     

Computer simulation of three-dimensional stellar systems in cylindrical coordinates

TheN-body problem does not have an exact and analytic solution, and computer technique or computer simulation can be a good candidate to solve it. Computing speed in computer simulation is very important. There are many algorithms and computational methods in computer simulation which reduce computer time.In this report a computer simulation model in a cylindrical coordinate, in which the FACR (Fourier Analysis and Cyclic Reduction) method is used, has been proposed and demonstrated the presence of spiral, barred, and ringed galaxy. The method using a cylindrical grid has good symmetrical properties specially for rotating stellar systems.     

Specialized celestial mechanics systems for symbolic manipulation

Construction and application of the current high accuracy analytical theories of motion of celestial bodies necessitates the development of specialized software for the implementation of analytical algorithms of celestial mechanics. This paper describes a typical software package of this kind. This package includes a universal Poisson processor for the rational functions of many variables, a tensorial processor for purposes of relativistic celestial mechanics, a Keplerian processor valid for the solutions of the two body problem in the form of a Poisson series, Taylor expansions in powers of time and closed expressions, and an analytical generator of celestial mechanics functions, facilitating the immediate implementation of the present analytical methods of celestial mechanics. The package is completed with a numerical-analytical interface designed, in particular, for the fast evaluation of the long Poisson series.     

GPS接收机中采样平均技术的FPGA实现

提出了一种采样平均的处理方法 ,将每毫秒 50 0 0点的采样信号变成每毫秒 1 0 2 4点 ,并利用现场可编程门阵列 (FPGA—fieldprogrammablegatearray)实现了这种方法。利用Matlab进行的仿真和ISE(insystememulator)综合结果表明这种方法不会影响信噪比 ,而且简化了接收机的相关处理器 ,节省了FPGA资源 ,降低了接收机成本 ,提高了处理速度 ,加快了设计进程     

Fringes on the EVN MkIV data processor at JIVE

The highlight of the 4th EVN/JIVE Symposium was the inauguration of the new EVN MkIV data processor at JIVE. This paper deals with the state of the processor in October 1998 and how it was used for fringe detection experiments.