A GUIDE TO THE INTERACTIVE ANALYSIS SYSTEM1. General In the period 01/12 to 31/12, several groups of visitors to the Observatory made use of the interactive analysis system and their experience, together with that of the Observatory Team, has led to a few general guidelines for the organization and proper exploitation of the system.
Users are reminded that the IA system was implemented primarily as a facility whereby the community could analyze EXOSAT data in more detail at the Observatory. There is no question of the Observatory Team undertaking a systematic interactive analysis (in the absence of the user) of data as a service - this is the function of the automatic analysis. It is recommended that users of the system should as far as possible be familiar with general X-ray data analysis techniques, since the support provided by the Observatory Team is geared in general towards a demonstration of the facilities rather than a 'supervision' of the entire analysis. First time users are expected to require a few hours full time advice from the Duty Scientists followed by consultancy support on specific details.
Real time interactive analysis of LE data will not be supported because of the excessive time required to linearise the image.
During the system trial period, which will terminate on 15.03.85, no real time booking will be permitted, i.e. P.I.'s attending their current observation must request IA system time in advance in the normal manner (EXPRESS no. 7, p. 43). Only one 'observer' will be allowed access to the system at any one time a although one observer means in practice one or two 'bodies'. From 15.03.85 to 31.03.85 the Observatory Team require 100% access to the computer system for configuration, coordination of final updates and testing and documentation such that a full service will be provided from 01.04.85.
Throughout the night period (23.00-08.00) no support of the IA system is in principle available, although the Observatory Controller will be able to offer some advice, consistent with the real time DCR operations having priority at all times.
Note that the software comprising the IA system is not an Observatory product, but rather a means of production and as such is not available for distribution outside the Observatory.2. The ME Interactive Analysis System
A description is given of the facilities that are supported, or will shortly be supported by the ME Interactive Analysis System. The two basic end products of the ME interactive analysis are spectral and rates files. These are used by a series of analysis programs, common to all the instruments, for spectral fitting, period searching, plotting etc.
Data from the following OBC modes can be analysed with the system: HER2, HER3, HER4, HER5, HER6, HTR3, PULS, PLS2, DIR2. Note that for the pulsar programs only spectral analysis can be carried out at present and for DIR2 only a very simple analysis is possible.
The data used to create a spectral file can be selected in the following ways:
1 - Argon or Xenon data
Background subtraction can be carried out
The detector gains are stored on the spectral file at the time of creation so that the effects of detector gain drifts and pre-amplifier gain setting changes are 'hidden' from the user. In addition, deadtime correction factors can be measured or calculated and applied to the spectra. Once a spectral file has been produced it can be plotted or used as an input to the spectral fitting program.
b) Light Curves
Light curve or 'rates' files can be produced with the following options:
1 - Argon or Xenon
In addition, the difference in intrinsic background counting rates can be corrected for using either array swap or slew data or standard background files. The file can be deadtime corrected and for some OBC modes the deadtime correction factors can be a function of time. The times stored in a rates file can be corrected to heliocentric times; note that Madrid is assumed to be at the centre of the world and the Sun at the solar system barycentre.
The rates files can be used as inputs to the following programs:
1 - Fourier Analysis
c) Other Facilities
Other important facilities supported by the ME Interactive Analysis include:
1) Directory listings - Listings of times, OBC
modes pointings of all
the observations on a FOT
The ME Interactive Analysis was designed to be used by a small number of scientists each of whom would be very familiar with all aspects of the operation of - the ME, the OBC, the HP computers and the OP analysis environment. As many of the astronomers coming to use the interactive analysis will not be familiar with these, much work is currently underway to improve the help files and level of documentation. In addition, analysis of high time resolution data is very time consuming mainly because of the low CPU power of the HP computers. A link to the ESOC Fujitsu main-frame computer has been established and it is expected that many of the CPU intensive processes will be transferred from the HP's to the Fujitsu
2. The LE Interactive Analysis System
The LE Interactive Analysis System consists of more than 10 programs to enable users to perform all the basic operations needed for the detailed analysis of CMA data.
The following is a list of the main options offered by the system:
Accumulate images* Accurate timing analysis of CMA data can be performed using LE rate files as inputs to the ME or GS timing programs or to the timing interactive system that is currently in preparation.
Several interactive programs suitable for the control of colour display devices are also available.
Documentation describing the LE interactive system is currently being written and will be available at the Observatory in the near future. A two-level help file and some documentation macros are already available on the HP4 computer system at ESOC.
4. The GSPC Interactive Analysis System