========== List of known problems in RODs for HRI data ====== 20_May-92 ===

This is a list of problems that were found in the past in ROD's for the HRI.
The correction date indicates whether your tape is likely to contain the
error. The list does not include inconsistencies in the Standard Image and
Source Analysis results. The ordering scheme is the EXSAS file name.

- attitude.tbl - missing_data    entered: 15-Mar92   corrected: 
  In a number of cases some auxiliary files like eventrates.tbl or 
  attitude.tbl do not have entries for all the accepted time intervals.
  This error will be initiated by previous data gaps.
  All affected data will be automatically reprocessed and sent out after 
  March 30, 1992.
- events.tbl - amplitude         entered: 20_Nov-91  corrected: 25_Nov-91
  After the recognition that the amplitude information available with each 
  event of the HRI detector might be useful for certain investigations, it
  has been added in the files events.tbl and difevents.tbl processed after
  November 25, 1991.
- events.tbl - descriptor        entered: 21_Nov-91  corrected: 25_Nov-91
  The TIM_SEL descriptor in events.tbl contains only half of the required
  entries (although the table contains all events). This affects directly 
  the value of the effective observation times ! Be careful with 
  intensities, fluxes etc..
- events.tbl - times             entered: 25_Nov-91  corrected:   -Dec-91
  In the file events.tbl the subsecond portion in the time information
  of individual events is missing.
- events.tbl - descriptor        entered: 02-Dec-91  corrected: 05_Dec-91
  Using the EXSAS command INTAPE/ROD to read your data from the tape to
  disk will produce (besides many other files) the file EVENTS.TBL. If
  you work in a UNIX environment you better change the filename to small
  characters.
- events.tbl - boresighting      entered: 01-Feb-92  corrected:
  If data from one observation were collected at two (or more) distinct 
  periods in time that are e.g. half a year apart (reobservation of targets
  not completed initially) than the boresight error between these periods
  may be as large as 20 arcsec leading to visibly distorted point
  spread functions. We are presently not able to correct this automatically.
  In principle the user has to run source detection on the contiguous time
  intervals separately, compare the source positions, determine the mean
  difference and correct the sky-pixel values in the events.tbl accordingly.
- events.tbl - wrong_times       entered: 20_Mar-92  corrected: 
  The arrival times of individual events in the file events.tbl are in
  some cases wrong by about 1 sec due to an sychronization problem. That
  error can affect the analysis of the timing behaviour of sources when
  times in the order of seconds or smaller are relevant.
- eventrates.tbl - missing_data  entered: 15-Mar-92  corrected: 
  In a number of cases some auxiliary files like eventrates.tbl or 
  attitude.tbl do not have entries for all the accepted time intervals.
  This error will be initiated by previous data gaps.
  All affected data will be automatically reprocessed and sent out after 
  March 30, 1992.

=============================== end of info ================================