File Database: Hsi_filedb

Each file that is written is recorded as an entry in the filedb structure. This is written into a FITS file, which is opened and read and rewritten for every ground station contact.

The database file for the level 0 data will be distributed as part of the software. This file is used by the routine HSI_FILEDB_FILENAME to find which file contains the data for a given time range.

Hessi Filedb structure, for each file

• version = A version number
• file_id = file name
• orbit_start = Orbit number (from GDS) at start of the file
• orbit_end = Orbit number (from GDS) at end of the file
• start_time = data start time, in ANYTIM format (Seconds from 1-Jan-1979)
• end_time = data end time, in ANYTIM format (Seconds from 1-Jan-1979)
• status_flag = set to -1 if the file has been deleted, and the packets are contained in another file, set to 0 if the file exists, but has not been processed for qlook data, set to 1 if the file has been processed.
• npackets = Number of packets in file
• clock_drift_start = value of the clock drift at the file start, the clock drift value is ADDED to the spacecraft clock time to adjust it properly.
• clock_drift_end = value of the clock drift at the file end

To read the filedb, call:

IDL> hsi_filedb_read, filedb, filedb_dir=filedb_dir, filename=filename

This returns the filedb structure from the file. The defaults for filedb_dir and filename are "$HSI_FILEDB_ARCHIVE" and "hsi_filedb.fits".The environmental variable "$HSI_FILEDB_ARCHIVE" is typically set to $ssw/hessi/dbase, and the file "hsi_filedb.fits" in this directory is the one created for the level 0 data. To write the filedb into a FITS file, call hsi_filedb_write, and for an ascii copy, call hsi_filedb_write_ascii.

Obtaining file names for a give input time range

If you are interested in archived HESSI data for a given time range, you can use the routine hsi_filedb_filename,

IDL> files = hsi_filedb_filename(time_range, filedb_dir=filedb_dir)

This call will return the filenames of all of the files that include data for the given time_range.