DB_TOFITS

COMMAND TYPE : UTILITY

PURPOSE:

To write a DIRA catalogue in FITS format.

DESCRIPTION:

A DIRA catalogue can be written in FITS format on tape or on disk; this is useful when the user wants to transport catalogues between two computer centers or he wants to insert data table in other astronomical packages, like MIDAS, that uses FITS as input formats. This command can be used to transport catalogues between two DIRA2 database; all the DIRA descriptors are saved in standard (and nonstandard) keyword. Moreover, the documentation file is written in a second table (XTENSION='DOCUMENT') in the FITS file. The coordinate fields are written using the DIRA standard formats.

The command DB_FROMFT can read these FITS files and insert catalogues in the data base without any more instruction. So the use of the commands DB_TOFITS : and DB_FROMFT is the best way to interchange catalogues (fully documented) between computer centers.

INPUT FIELDS of the command:

From: PDB ?

The user must enter Y when the catalogue that the user wants to convert is in Personal Data Base.

Example : Y

Catalogue Name

The name of the input catalogue. The user can have the list of the catalogues available entering a L after the help (invoked with the "?" key )

Example : UGC

Output: Screen

When this flag is set to Y the FITS header of the new file will be written on the screen.

Example : Y

Output: File name

The name of the output FITS file. If the file is written on tape the user must enter here the name of the tape unit.

Example : MSA0:

Output: BlocFat

If the catalogue is written on tape the user can define the Block Size of the physical records. This number can be, for a standard FITS file, from 1 to 10. The value of 10 reduces the use of tape space, but old versions of the package that read FITS format can read tape with block size = 1 only.

Example : 10

NOTE:

To export all the DIRA catalogue items the standard set of keywords of the FITS has been enlarged. This new, nonstandard, keywords are :

DIRACAT1, DIRACAT2, DIRACAT3, DIRACAT4, DIRACAT5

DIRADOC1, DIRADOC2, DIRADOC3, DIRADOC4, DIRADOC5

that contain the records of the master files DIRACAT.DB and DIRADOC.DB relative to the catalogue.

These keywords are read by the DB_FROMFT to have the complete description of the catalogue.



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