The ABC of XTE
Introduction
Introduction
Postscript version of this chapter
- Scope
- RXTE Data Reduction: The Basic Scheme
- How this Guide is Organized and How to Use it
- Obtaining Help and Information, Reporting Bugs, etc.
This Guide tells you what you need to know to reduce RXTE data. By reduce, we mean the preparation of data for analysis, which for RXTE entails knowing:
Between receiving RXTE data from the ground station and sending the
data to Guest Observers, the RXTE data processing pipeline converts the
data to FITS format, arranges the FITS files into a hierarchical
set of directories, and performs a set of standard calibrations.
RXTE data reduction involves first navigating the directory structure with
the GUI-driven program XDF (XTE Data Finder) to identify the files
which contain the data you want to reduce. Next, you manipulate these
FITS files by a set of tasks, called ftools. The ftools may also be
used to produce a filter file that contains the time-histories of
various parameters, in reference to which good data can be identified and
screened. Using a filter file for the observation, you can produce a list
of good time intervals based on various selection criteria you apply. At
this stage, you can also specify filters to single out parts of the good
data. The final step is to apply the good time intervals and extract data
products (light curves or spectra) through the filters. These products
can be read into the appropriate data analysis programs (e.g. xronos,
xspec - or any others equipped to handle the formats).
RXTE might seem at first to be a very complicated mission. Not only are the two PI instruments, the PCA and HEXTE, modular, but they can each produce data in an almost endless variety of modes. Fortunately, when you get your data tape, you'll find that the only modes present are the ones you chose for your proposal, plus the so-called "standard modes". Moreover, RXTE science data are packaged in just two broad classes, science array and science event, and only two extractor tools are needed.
After this introduction, comes a chapter dealing with the basic structure of the various RXTE FITS files. Not an exhaustive description of the files and keywords, the chapter focuses instead on the properties of the files that you need to know in order to reduce and analyze your data effectively.
The next chapter describes those aspects of the PCA that pertain to data reduction. Like the chapter on FITS files, the aim is to enable you to understand the properties of your data.
Screening, i.e. getting rid of unwanted or invalid data, is covered in the next chapter which is followed by the chapter on extracting light curves and spectra. A tutorial on how time is defined for RXTE ends this current version.
Before the ABC of XTE, you should read the RXTE Getting Started Guide.
If you are familiar with ASCA data reduction, please read this footnote which discusses the similarities and crucial differences between ASCA and RXTE data reduction.
The ABC of XTE is intended as a comprehensive reference on RXTE data
reduction. The RXTE Cook
Book provides easy-to-use recipes for basic and advanced
data reduction tasks.
XDF, xselect2, the ftools and the Xanadu analysis programs are all
equipped with extensive on-line help, but if you cannot find the answer
to your software question, please send email to
xtehelp@athena.gsfc.nasa.gov
This is also the email address to which you should send bug reports
and comments.
Information about software and calibration updates, bug fixes and enhancements is promulgated via the xtenews email exploder. Xtenews is also used to distribute the short-term timelines. If you are not on the mailing list of this exploder, please send an email to listserv@athena.gsfc.nasa.gov which should contain, in the text of the email, the single line:
Scope
Data analysis, i.e. the derivation of scientific results from the data products, is covered elsewhere, although the chapters on spectra and light curves do show how to get started on your analysis.
RXTE Data Reduction: The Basic Scheme
How this Guide is Organized and How to Use it
The Overall Scheme
The Order and Arrangement of Chapters
How to Use this Guide
Obtaining Help and Information, Reporting Bugs, Submitting
Comments, Receiving Updates
Xtehelp
Xtenews
subscribe xtenews Felix Krull
provided your name is Felix Krull (if it is not, please substitute your own name).
The ABC of XTE is written and maintained by the RXTE GOF. Please email xtehelp@athena.gsfc.nasa.gov if you have any questions or comments. This particular page was last modified on Wednesday, 17-Mar-2004 15:19:00 EST.