observer/weekly_timeline/README
updated AUG-08-94

1.0  INTRODUCTION

Available in the weekly_timeline sub-directory is the Preliminary HST 
Observing Timeline Reports (or Weekly Timeline) generated from the Science
Mission Specification (SMS).
The SMS generally begins on Monday and usually covers 1 week. The SMS name
is of the form YYDOYVVV, where YY is the year, DOY is the day of the
year of the first day in the SMS and VVV is the version (the version
number is not significant).

The report is usually generated 1 month prior to the beginning of a
week's observations. Observations on this report will usually be
executed, but problems with the spacecraft, scientific instruments,
communications contacts or other events beyond our control may disrupt
the timeline.

The times used in the Weekly Timeline are the scheduling unit (SU) times. 
Observations belonging to the same SU will have the same SU begin and end
times.  Each observation in the SU will have a separate entry in the report. 

2.0  FTP SUB-DIRECTORY AND FILE NAME DESCRIPTIONS

The FTP directory/sub-directory/file structure for the Timeline Observing
Reports is depicted below: 

			FTP STSCI
			   |
			Observer
			   |
		     weekly_timeline
			   |
		    timeline_dd_mm_yy
			   .
			   .
			   .

    where: timeline_dd_mm_yy =   
				 dd  => day
				 mm => month
				 yy => year 


The weekly_timeline sub-directory will normally contain only 1 report for each
"week".

The timeline reports will remain on STEIS until all observation sets have been 
accounted for as completed or missed.  When the accounting is complete, a
report will entered in the following STEIS sub-directory.

	/observer/completed_observations 

3.0  REPORT FIELD DESCRIPTIONS

The fields in this report are:

Scheduling Unit
Begin UT		Earliest start time in YYYY DOY HH:MM:SS for this SU.
End UT			Latest end time in HH:MM:SS for this SU.
SU ID			Scheduling Unit Identifier => pppppss:vv
			where:  ppppp = proposal ID
				ss = SU number for that proposal (base 36)
				vv = version number of the SU (usually 01)

Principal Investigator	1st 10 characters of PI last name

ELOG#                   Proposal Logsheet line # for this observation 

Target			1st 10 characters of target name

Science Instrument	Main SI used by this observation

Mode			SI Operating Mode used by this observation

R/T			Identifies real-time observations.
			blank =>  no real-time has been requested
			R => return link requested (downlink)
			F => forward link requested (uplink)
			B => both return and forward links requested

Apertures		Aperture(s) (up to 4) associated with this observation 

Spectral Elements	Filters/gratings (up to 4) associated with this 
                        observation

Tape Recorder           Designates whether tape recorder data collection
			is associated with this observation.
			blank => no recording
			Y => tape recorder used for data collection
                        B => tape recorder used in backup mode for data 
                        collection. Typically seen with R/T field set to R or B.

Obset ID		Observation Set ID
			(An obset is generally one or more alignments that can 
			use the same Guide Star(s) or Pointing Control 
                        System mode

Alignment ID		Alignment ID
			(An alignment is generally one or more exposures, done 
			 back to back, with the same telescope pointing)

Exposure ID		Exposure ID
			(An exposure is essentially one instrument operation.
                         Exposure IDs are different than Proposal Logsheet
                         Line numbers.)

Note: SU, Obset, Alignment and Exposure IDs are base 36 (01, 02..., 09,
0A, 0B, ..., 0Z, 10, ...)