Development of computation-intensive X-ray signal prcesssing system for X-ray calorimeter

本计画的目的是发展一个小型的电脑系统，以进行时间序列讯号的撷取与即时数位讯号处理。该系统的主要目的是对X射线量热计的信号进行采集和实时数字处理。利用X射线量热计输出的信号具有与音频信号相似的特征时间尺度的特点，我们使用了最初为实时音乐/声音合成而开发的信号处理工作站ISPW（IRCAM Signal Processing Workstation）来测量X射线量热计输出的X射线信号。利用该系统，我们从X射线量热计获取信号，应用数字滤波器，然后将结果记录在计算机文件中。我们已经证明，信号处理程序可以建立使用可视化编程语言结合快速数学库。来自放大器输出的X射线量热计信号被馈送到模数转换器，数字信号通过其DSP端口接口传输到ISPW。ISPW执行数字处理，结果以可视方式显示或写入主机（NeXT Cube）上的文件。最初我们计划从头开始构建软件。然而，我们发现，视觉编程语言“最大”，开发的声音/音乐合成是有能力的，实际上适合于事件驱动的信号处理。使用Max可以方便地构建时间序列数据分析系统，并可作为天文卫星实时时间序列信号分析的原型工具。

The purpose of this project is to develop a small computer system for time-series signal acquisition with real-time digital signal processing. The primary purpose of this system is the acquisition and real-time digital processing of signals from X-ray calorimeter. Taking advantage of the fact that the signals from X-ray calorimeter have characteristic timescale similar to the audio signals, we used the signal processing workstation ISPW (IRCAM Signal Processing Workstation), which was originally developed for real-time music/sound synthesis, for the measurements of X-ray signals from X-ray calorimeter. With this system, we acquired the signal from the X-ray calorimeter, applied digital filters, and then recorded the results on the computer files. We have demonstrated that the signal processing procedures can be built using the visual programming language combined with fast mathematical libraries. The X-ray calorimeter signals from the amplifier output are fed to the analog-to-digital converter, and the digital signal is transferred to ISPW via its DSP port interface. The ISPW performs the digital processing, and the results are visually displayd or written to the files on the host (NeXT Cube) computer.Originally we planned to build the software from scratch. We found, however, that the visual programming language "Max", developed for sound/music synthesis is capable, and actually suitable for event-driven signal processing. With Max, it is easy to construct a system to analyze time-series data, and is useful as a prototyping tool for the real-time time-series signal analysis on astronomical satellites.