ASKAP Science Data Processor software - ASKAPsoft Version 0.19.6

ASKAPsoft, the ASKAP Science Data Processor, provides data processing functionality, including:* Calibration* Spectral line imaging* Continuum imaging* Source detection and generation of source catalogs* Transient detectionASKAPsoft is developed as a part of the CSIRO Australian Square Kilometre Array Pathfinder (ASKAP) Science Data Processor component. ASKAPsoft is a key component in the ASKAP system. It is the primary software for storing and processing raw data, and initiating the archiving of resulting science data products into the data archive (CASDA).The processing pipelines within ASKAPsoft are largely written in C++ built on top of casacore and other third party libraries. The software is designed to be parallelised, where possible, for performance.ASKAPsoft is designed to be built and executed in a standard Unix/Linux environment and core dependencies must be fulfilled by the platform. These include, but are not limited to, a C/C++/Fortran compiler, Make, Python 2.7, Java 7 and MPI. More specific dependencies are downloaded by the ASKAPsoft build system and are installed within the ASKAPsoft development tree. Specific to the Debian platform, after a standard installation of Debian Wheezy (7.x) the following packages will need to be installed with apt-get:* g++* gfortran* openjdk-7-jdk* python-dev* flex* bison* openmpi-bin* libopenmpi-dev* libfreetype6-dev* libpng12-devMore information regarding the building, installation and running of the software can be found in the README file in the root of the file structure that forms this collection.Source code can be accessed via the links in Related Materials section.-----Pipelines: * The default imager has been changed *for all imaging jobs* to be the new imager task. * Image-based continuum subtraction script made compatible with ACES script changes. Needs to be used with ACES revision number 47195 or later. * The bandpass solutions can now be applied to calibrator themselves, producing calibrated MSs. * Reference antenna for bandpass calibration specified via the new parameter BANDPASS_REFANTENNA. * Self-calibration with cmodel can now avoid using components below some nominated signal-to-noise level. It can also be forced to use PSF-shaped components for the calibration. * The first stage of mosaicking now uses the weighttype=Combined option (see below), which should give a better reflection of the data in the event different beams have different weights. * Some bug fixes (see CHANGES file) Processing software: * Cflag: - Fixed bug where the StokesV flagger would crash with a segmentation fault on occasions where it was presented with a spectrum or time-series that was entirely flagged. * Imager: - The imager is now more robust against small changes in the frequency labels of channels, with an optional tolerance parameter available. * Selavy: - A few bugs were fixed that were preventing Selavy working for spectral-line cubes, where it was trying to read in the entire cube on all processing cores (leading to an out-of-memory error). - Moment-0 maps now have a valid mask applied to them. - Selavy can now measure the spectral index & curvature from a continuum cube, instead of fitting to Taylor-term images. - Duchamp version 1.6.2 has been included in the askapsoft codebase. - The deconvolved position angle of components is now forced to lie between 0 & 2pi, and its error is limited to be no more than 2pi. * Linmos: - Fixed a bug that meant (in some cases) only a single input image was included in the mosaic. Happened when the input images had masks attached to them (for instance, combination of mosaics). - New option of "weighttype=Combined" for linmos-mpi, that uses both the weight images and the primary beam model to create the output weights.ASKAPsoft，即ASKAP科学数据处理器（ASKAP Science Data Processor），可提供数据处理功能，涵盖： * 校准 * 谱线成像 * 连续谱成像 * 源探测与源星表生成 * 暂现源探测 ASKAPsoft作为澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation, CSIRO）旗下澳大利亚平方公里阵列探路者（Australian Square Kilometre Array Pathfinder, ASKAP）科学数据处理器组件的组成部分，是ASKAP系统的核心组件之一。它是存储与处理原始数据、并启动将生成的科学数据产品归档至数据归档系统（CASDA）的核心软件。 ASKAPsoft内置的处理流水线大多基于casacore与其他第三方库，采用C++语言编写。该软件在可行范围内进行了并行化设计，以提升运行性能。 ASKAPsoft可在标准Unix/Linux环境中编译与运行，平台需满足核心依赖项，包括但不限于C/C++/Fortran编译器、Make、Python 2.7、Java 7以及消息传递接口（MPI）。更多特定依赖项将由ASKAPsoft构建系统自动下载，并安装至ASKAPsoft开发树中。针对Debian平台，在标准安装Debian Wheezy（7.x）后，需通过apt-get安装以下软件包： * g++ * gfortran * openjdk-7-jdk * python-dev * flex * bison * openmpi-bin * libopenmpi-dev * libfreetype6-dev * libpng12-dev 有关该软件的构建、安装与运行的更多详细信息，可参阅此数据集根目录下的README文件。源代码可通过「相关材料」板块中的链接获取。 ----- 流水线更新： * 所有成像任务的默认成像器已更改为新的成像器任务。 * 基于图像的连续谱减除脚本已适配ACES的脚本变更，需搭配ACES修订版47195或更高版本使用。 * 现在可将带通校准解应用至校准源本身，以生成已校准的测量集（Measurement Set, MS）。 * 可通过新增参数BANDPASS_REFANTENNA指定带通校准的参考天线。 * 借助cmodel进行自校准时，可忽略低于指定信噪比阈值的成分；同时支持强制使用点扩散函数（Point Spread Function, PSF）形状的成分参与校准。 * 拼接成像的第一阶段现已使用weighttype=Combined选项（详见下文），在不同波束权重存在差异的场景下，可更准确地反映数据特性。 * 修复了若干缺陷（详见CHANGES文件）。 ----- 处理软件更新： * Cflag模块：修复了斯托克斯V（Stokes V）标记器在处理完全被标记的频谱或时间序列时，偶尔出现段错误崩溃的问题。 * 成像器：新增可选容差参数，可增强成像器对通道频率标签小幅变化的鲁棒性。 * Selavy： - 修复了若干导致Selavy无法正常处理谱线立方体的缺陷，此前该问题表现为所有处理核心尝试加载整个立方体，进而引发内存溢出错误。 - 矩0图现已应用有效掩膜。 - Selavy现在可直接从连续谱立方体中测量谱指数与谱曲率，无需再拟合泰勒项图像。 - 已将Duchamp 1.6.2版本纳入askapsoft代码库。 - 成分的去卷积位置角现已强制限制在0至2π范围内，且其误差上限设为2π。 * Linmos模块： - 修复了部分场景下仅单幅输入图像被纳入拼接结果的缺陷，该问题常出现在输入图像附带掩膜的情况（例如多幅拼接图的组合）。 - 为linmos-mpi新增weighttype=Combined选项，可同时使用权重图像与主波束模型来生成输出权重。