The Leicester Ginga Archive: Software Archive

If you are interested in a Ginga observation not included in the products database (e.g. MPC2, MPC3 or PC mode data), then you must extract the data from the raw Ginga data files made available through the LEDAS archives. There are two routes to extracting Ginga raw data:

GINGAFRF

The original Ginga First Reduction Files (FRFs) are available in HDS format through the GINGAFRF database table. You will need to use the Leicester Ginga data analysis software to analyse this data. A copy is available for local installation from our anonymous ftp site at ftp/ginga/soft. Documentation is also available as a postscript file from the same ftp site at ftp/ginga/doc, or as an HTML document. The data analysis software runs under the OSF/1 operating system on DEC Alpha machines only. Please note that this software is not intended for general use as it still requires expertise to fully exploit the data, and that only limited effort is made available to support its use at remote sites. If you have not analysed Ginga data before you are advised to contact us first. Unfortunately, our resources do not allow remote use of this software on the LEDAS machine.

GINGARAW

The Ginga FRFs are also available in FITS format through the GINGARAW database table. The FITS Ginga data are the FRF files converted into FITS format from their native format (ADP grant, PI Corbet, at Penn State). The FITS files are bintable with 5 extensions containing raw counts (science data), raw orbital data, raw operational status data, raw housekeeping data and good time intervals. The layout of the science data extension consists of several columns containing counts, stored as an array per row, and one containing time. The datamode sets the number of channels for the count arrays, how the signal from each counter is summed (number of columns) and the integration time.

The GINGARAW database was derived using keywords stored in the primary header of the FITS file. Each record corresponds to a different pointing position, therefore it is possible that up to 3 records are associated with the same FITS file, but different object name and position.

For further information on generating and processing GINGARAW FITS files, see the Ginga FITS Data System (GFDS) project page at Penn State. The site provides software and documentation for the GFDS system.

Background modelling

A parallel activity to the making of the products database was the creation of background models for the duration of the Ginga mission. These models are crucial to the analysis of Ginga data, as the main instrument has no means of simultaneously monitoring the background count rate. A number of measured and calculated rates were used to derive the spectral-temporal background variations due to particle interactions with the material of the satellite and its subsequent radioactive decay (see Hayashida et al. 1989). These models have been made available with the software.