The Yohkoh prefix description database is broken into five parts.
   1. The three letter file prefix
   2. A short one line description of the file
   3. A specifier on the type of file (how often the file is made)
   4. A long description of the file
   5. A description on how/when the file is made, and whether it is on 
      the archive tapes.  Values include
		REF_Daily	- the file is made daily by AUTO_TOBAN
		REF_Weekly	- the file is made weekly by REF_SUPER
		Weekly_Tape	- the file is included in the data portion of
				  the archive tape
		Weekly_Tape_Tar	- all files for the whole mission are included
				  in a tar file at the end of the archive tape
		YDB1_Tape	- YDB files that should definitely be on
				  a YDB distribution tape (they are Yohkoh)
		YDB2_Tape	- YDB files that should probably be on a
				  YDB distribution tape (they are public 
				  domain)
		YDB3_Tape	- YDB files that need special permision to be
				  on a YDB distribution tape (they are public 
				  domain)

Weekly files have the following name convention
	xxxYY_WWa.##	(obs91_38a.01 for example)
			where	xxx = the prefix
				YY  = the year
				WW  = the week number
				 a  = reserved
				##  = the file version number

The file which exist per orbit have the following name convention
	xxxYYMMDD.HHMM	(spr921123.2007)
			where	xxx = the prefix
				YYMMDD = the year, month, and day
				HHMM   = the hour and minute
********************************************************************************

ADA 	S/C Attitude Raw Reformatted Data			per Orbit
					The ADA file has all of the raw pointing information available from
					the S/C.  It includes 8 Inertial Reference Unit (IRU) values per major 
					frame (a MF covers 2 sec in high rate), 4 Geomagnetic Attitude Sensor 
					(GAS) values per MF, 4 Two-Dimensional Fine Sun Sensor (TFSS) values 
					per MF, 4 Non-Spin Type Attitude Sensor (NSAS) per MF, Star Tracker 
					(STT) information, and 2 HXT 2-D Aspect Sensor (HXA) values per MF.
					The data should be in one of the YDn data directories.
						[REF_Daily, REF_Weekly, Weekly_Tape]
ATR	Raw S/C Attitude Database				Weekly
					The ATR file (eg: atr92_26a.01) has one dataset per major frame for 
					each non-night major frame of data available.  Each dataset has the 
					single IRU, TFSS, and HXA values for that major frame, along with
					the DP mode and DP rate.  The data are in the $DIR_GEN_ATR directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, YDB1_Tape]
ATT	Processed S/C Attitude Database				Weekly
					The ATT file contains the reduced S/C attitude information.  The
					sun center position is derived for each non-night major frame
					using the IRU and HXA data.  The coordinate system used is the
					center SXT pixel of the sun.  The mainframe ground derived 
					attitude determination software (ADS) results for the S/C
					roll are also written into the ATT file.  The data are in the 
					$DIR_GEN_ATT directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, YDB1_Tape]

BDA 	BCS Raw Reformatted Data				per Orbit  
					The BDA files contain the raw reformatted BCS data.
					The data should be in one of the YDn data directories.
						[REF_Daily, REF_Weekly, Weekly_Tape]

BSD 	*OLD* BCS Instrument Calibrated Spectra			User Specified
					The BSD file is produced by the F77 program MKBSD. It consists
					of spectra extracted from the BDA file, with instrument corrections
					applied.
BPC 	*OLD* BSDCAL Output (parameters)			User Specified
					BPC is an intermediate file which contains fit information 
					derived by the F77 program BSDCAL that is used by the F77 program
					BSDFIT as a first guess for a comparison with synthetic spectra
BTH 	*OLD* BSDFIT Output (Fitted Spectra)			User Specified
					BTH contains parameters describing the synthetic spectral fit
					performed by the F77 program BSDFIT to the observations.
BFT 	*OLD* BSDFIT Output (parameters)			User Specified
					BFT contains synthetic spectra created during the fit performed
					by the F77 program BSDFIT.

BSC 	*NEW* BCS Instrument Calibrated Spectra			User Specified
					The BSC file is produced by the IDL routine MK_BSC. It consists
					of spectra extracted from the BDA file, with instrument 
					corrections applied.
BSA 	*NEW* Answer File for BSC Generation			User Specified
					BSA is a control file that can be created when preparing to run
					the IDL routine MK_BSC. The information in this file is contined
					within the BSC file after it has been generated.

BSF 	*NEW* Output from Spectral Fitting			User Specified
					BSF files contain fit information derived by FIT_BSC when making
					synthetic spectra.

CBA 	S/C Common Basic Raw Reformatted Data			per Orbit     
					The CBA file contains a full copy of the Basic Part for every major
					frame of the telemetry.  The Basic Part is the first 4 columns of the
					telemetry minor frame and consists of 1/4 of all of the telemetry.  The
					relevant instrument data are extracted from this part and put into the
					instrument files. The data should be in one of the YDn data directories.
						[REF_Weekly, Weekly_Tape]

EVN 	Yohkoh Event Log					Weekly     
					The EVN file contains an entry for every time there is a change in DP
					mode (Quiet/Flare) or when there is a gap in continuous data of more 
					than one minute.  The entry contain information about how many images 
					and spectra are available for each instrument during that period, the 
					peak counts for each channel of the instruments, and the location of 
					the SXT PFI.  The data are in the $DIR_GEN_EVN directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, Weekly_Tape_Tar, YDB1_Tape]

FEM 	Yohkoh Orbital Ephemeris				Weekly     
					The FEM file has a dataset for each time the S/C has a night to day
					transition.  The times of any SAA passages and station contacts are 
					also saved in these files.  The files are created using the orbital 
					solutions which are derived weekly by NASDA.  The data are in the 
					$DIR_GEN_FEM directory.
						[Weekly_Tape, Weekly_Tape_Tar, YDB1_Tape]
GEV 	GOES Event Log						Weekly  
					The GEV file contains the start, stop and peak times of a flare event,
					the GOES classification, the H-alpha importance level, the location in
					heliocentric coordinates, the NOAA active region number, and the radio
					fluxes.  This binary file is created from the SELSIS/NOAA text
					event files.  The data are in the $DIR_GEN_GEV directory.
						[Weekly_Tape_Tar, YDB2_Tape]
GXT 	GOES One Minute Light Curve Data			Weekly  
					The GXT file contains the one minute average count rate for the GOES-6
					and GOES-7 low and high energy channels.  This binary file is created 
					from the tektronics plot files.  The data are in the $DIR_GEN_GXT 
					directory.
						[Weekly_Tape_Tar, YDB2_Tape]
G6D	GOES 3 Sec Light Curve for S/C 6			Weekly
					G6D files hold the digital raw (unprocessed) three second light curve 
					data for the GOES-6 spacecraft.  
					The data are in the $DIR_GEN_G6D directory.
						[YDB3_Tape]
G7D	GOES 3 Sec Light Curve for S/C 7			Weekly
					G7D files hold the digital raw (unprocessed) three second light curve 
					data for the GOES-7 spacecraft.  
					The data are in the $DIR_GEN_G6D directory.
						[YDB3_Tape]
GXD 	GOES Derived One Minute Light Curve Data		Weekly     
					GXD file is generated from the G6D and G7D files and has information
					similar to the GXT file.  ** Not Available (Oct-93) **
						[YDB3_Tape]

...
GBE	GRO BATSE Event Log					Mission
					The GBE file contains information on BATSE flare events.
					It contains the start time, peak time, end time, BATSE event
					number, peak counting rate, and total counts detected.
					There were approximately 3880 events between 1-May-91 and 1-Apr-93
					The data are in the $DIR_GEN_GBE directory.
						[YDB3_Tape]
GBL	GRO BATSE Light Curves					Weekly
					The GBL file contains the light curves for BATSE flare events.
					There were approximately 3880 events between 1-May-91 and 1-Apr-93
					The data are in the $DIR_GEN_GBL directory.
						[YDB3_Tape]
...
G_x	Ground-Based Observation (GBO) Images (Sites)		per Image (FITS)
					The second letter is the site:
						B = Big Bear
						C = Boulder Colorado
						G = Goddard Space Flight Center
						H = Holloman
						J = CRL/Hiraiso
						K = Kitt Peak
						L = Leamonth, Australia
						N = NAOJ, Nobeyama, Norikura
						P = Palehua (SOON)
						R = Ramey (SOON)
						S = San Vito (SOON)
                        
Gx_	Ground-Based Observation (GBO) Images (Data Type)	per Image (FITS)
					The third letter is the type of image
						C = Large Scale H-Alpha
						G = Green Light Image (5303 A)
						H = H-alpha
						I = HeI 10830 A
						K = Calcium
						M = Magnetogram
						P = Polarized Radio (17 GHz) (R-L)
						R = Red Light Image (6374 A)
						S = Spectrohelioscope
						T = Total Intensity Radio (17 GHz) (R+L)
						W = white light
						X = X-ray
						Y = Yellow Light Image (5694 A)
...
GBC 	GBO Big Bear Large Scale H-alpha PFI FITS Image		per Image (FITS)
GBH 	GBO Big Bear H-alpha FITS Image				per Image (FITS)  
GBK 	GBO Big Bear Calcium FITS Image				per Image (FITS)  
GBW 	GBO Big Bear White Light FITS Image			per Image (FITS)     
...
GCH	GBO Boulder Colorado H-alpha FITS Image			per Image (FITS)     
GGH	GBO GSFC H-alpha FITS Image				per Image (FITS)     
GHH	GBO Holloman H-alpha FITS image				per Image (FITS)     
GLH	GBO Leamonth Australia H-Alpha FITS Image		per Image (FITS)     
GNH	GBO NAOJ Japan H-alpha FITS Image			per Image (FITS)     
GJH	GBO CRL Hiraiso H-alpha FITS Image			per Image (FITS)     
...
GKI 	GBO Kitt Peak He 10830 FITS Image			per Image (FITS)  
GKM 	GBO Kitt Peak Magnetogram FITS Image			per Image (FITS)     
...
GNP	GBO Nobeyama Polarized Radio Image (17 GHz)		per Image (FITS)    
					The Nobeyama polarized radio images (GNP) are copied daily to
					the ISAS Yohkoh database.  The images are scaled from REAL data
					type into BYTE type to save space.  A single image per day is
					available after Apr-93.
GNT	GBO Nobeyama Total Intensity Radio Image (17 GHz)	per Image (FITS)     
					The Nobeyama total intensity radio images (GNT) are copied daily 
					to the ISAS Yohkoh database.  The images are scaled from REAL data
					type into BYTE type to save space.  A single image per day is
					available after Apr-93.
...
GOL	GBO Observing Log					Weekly
					The GOL file contains an entry for each GBO image available, with
					the date/time of the image, the site, the image type, and a
					variety of other information.  The data are in the $DIR_GEN_GOL
					 directory.
						[YDB2_Tape]

HDA 	HXT Raw Reformatted Data				per Orbit  
					The HDA files contain the raw reformatted HXT data.
					The data should be in one of the YDn data directories.
						[REF_Daily, REF_Weekly, Weekly_Tape]
HXI 	HXT Synthesized Image					User Specified

MDM	Magneto-Optical (MO) Map				Mission
					The MDM file contains the information on which raw orbital reformatted
					data files are written to which magneto-optical (MO) disk.  The MDM 
					file is saved using SAVGEN.  The data are in the $DIR_GEN_MO directory.
						[YDB1_Tape]

NAR 	NOAA Active Region					Weekly     
					The NAR file contains the NOAA active region number, the location in
					heliocentric coordinates, the longitude of active region, the area of 
					the active region in millionths, the MacIntosh classification, the 
					longitude extent in degrees, the number of spots and the magnetic 
					type.  The binary file is is created from the SELSIS/NOAA text region 
					files.  The data are in the $DIR_GEN_NAR directory.
						[Weekly_Tape_Tar, YDB2_Tape]
...
NEL	Nobeyama Radio Observatory Event Log			Mission
					The NEL file simply tells the user the hours of each day when the
					Nobeyama Radio Observatory was observing.  The data are in the 
					$DIR_GEN_NEL directory.
						[YDB2_Tape]
NTS	Nobeyama Radio Observatory Time Series			Weekly
					The NTS file has the time series of correlation coefficients for
					the Nobeyama Radio Observatory.  The data are in the $DIR_GEN_NTS
					directory.
						[YDB2_Tape]
OBS 	*OLD* Yohkoh Observing Log					Weekly     
					The observing log (OBS) for all instruments used to be combined in a
					single OBS file.  In mid-1993 the entries were broken into separate
					files for more efficiency.
						[REF_Daily, REF_Weekly, Weekly_Tape]
OBD	BCS Observing Log					Weekly
					The BCS observing log (OBD) contains an entry for each BCS spectrum
					(no more than one every 4 seconds).  The entry is created from the
					roadmap and DP sync structures.  Information on the instrument modes
					and the counting rates are available.  Light curves or seaches for
					certain observing modes can be performed using this log.  The data 
					are in the $DIR_GEN_OBD directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, YDB1_Tape]
OSF	SXT Full Frame Observing Log				Weekly
					The SXT full frame observing log (OSF) contains an entry for each 
					full frame image taken.   The entry is a copy of the roadmap and
					contains information on the DP mode, filter user, exposure level,
					average and peak DN level, and other information.  The data are 
					in the $DIR_GEN_OSF directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, YDB1_Tape]
OSP	SXT Partial Frame Observing Log				Weekly
					The SXT parital frame observing log (OSP) contains an entry for each 
					partial frame image taken.   The entry is a copy of the roadmap and
					contains information on the DP mode, filter user, exposure level,
					average and peak DN level, and other information.  The data are in 
					the $DIR_GEN_OSP directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, YDB1_Tape]
OWH	WBS/HXT Observing Log					Weekly
					The WBS and HXT observing log (OWH) are combined together.
					There is an entry for every 2 major frames.  The entry is created 
					from the roadmap structure of each instrument.  Information on the 
					instrument modes, as well as the counting rates are available in 
					each entry.  Light curves or searches for certain observing modes 
					can be performed using the observing log.  The data are in the 
					$DIR_GEN_OWH directory.
						[REF_Daily, REF_Weekly, Weekly_Tape, YDB1_Tape]

PNT 	*OLD* S/C Pointing File					Weekly     
					The PNT database was replaced by the ATR and ATT databases in
					mid-1993.  The ATR database holds the raw spacecraft attitude data
					and the ATT database holds the processed attitude information.
						[REF_Daily, REF_Weekly, Weekly_Tape]

SDL 	SXT Dark Current Log					Weekly  
					The SDL file contains the histogram for every dark image which is 
					taken.  From the histograms, the average signal and standard 
					deviation can be calculated.  The DN value and location of the 128 
					brightest dark spikes is also available for every dark image taken.
					These are non-image data.  The data are in the $DIR_SXT_SDL directory.
						[REF_Weekly, YDB1_Tape]
SDC 	SXT Dark Current Images					Weekly (SDA)  
					The SDC file contains the reference dark images to be used for 
					background subtraction when the CCD is cooled to -21 C.  The data 
					are in the $DIR_SXT_SDC directory.
						[REF_Weekly, Weekly_Tape, YDB1_Tape]
SDW 	SXT Dark Current Images for Warm CCD			Weekly (SDA)  
					The SDW file contains the reference dark images to be used for 
					background subtraction when the CCD is not cooled.  A separate 
					image is saved for every unique temperature.  The data are in the 
					$DIR_SXT_SDW directory.
						[REF_Weekly, Weekly_Tape, YDB1_Tape]
SDP 	SXT Dark Current PFI Images 				Weekly (SDA)  
					The SDP file contains all partial frame dark images which are
					complete (not missing portions).  All images for all resolutions,
					exposure levels and temperatures are saved.  The data are in the 
					$DIR_SXT_SDP directory.
						[REF_Weekly, YDB1_Tape]

SFD 	SXT FFI Desaturated Composite Images			Weekly (SDA)  
					The SFD files (eg: sfd92_25a.03) are the SXT full-frame desaturated
					images (combination of long and short exposures to eliminate 
					saturation spikes on the CCD).  The two exposures must be taken 
					less than 10 minutes apart, be complete, and not taken during earth 
					eclipse.  The background is subtracted using the nearest available 
					suitable dark frame and the exposures and resolutions are normalized.
					The data are in the $DIR_SXT_SFD directory.
						[REF_Daily, REF_Weekly, Weekly_Tape]
SFR 	SXT FFI Raw Reformatted Data				per Orbit (SDA)  
					The SFR file is the raw data file which contains the full-frame
					images.  The final SFR files are a single file per orbit, but 
					the temporary files can span more than an orbit.  The data should be 
					in one of the YDn data directories.
						[REF_Daily, REF_Weekly, Weekly_Tape]
SFS 	SXT FFI Special Images (diffuser, flood...)		Weekly (SDA)  
					The SFS database contains all images taken in compressed mode using 
					the diffuser, UV flood, or open filter positions.  The data are in 
					the $DIR_SXT_SFS directory.
						[REF_Weekly, YDB1_Tape]
SFT	SXT FFI Terminator Images				Weekly (SDA)
					The SFT file contains all of the sunset images.  These are images
					taken as the S/C goes behind the earth, and the earth's atmosphere
					attenuates all the X-rays, leaving a good calibration image of
					the pin hole and light leak caused by the Nov-92 entrance filter
					failure.
						[REF_Daily, REF_Weekly]
SFW 	SXT FFI White Light Images				Weekly (SDA)  
					The SFW file contains all complete optical images for the week.
						[REF_Weekly, Weekly_Tape]
SFC	SXT FFI Calibration (Leak) Image			per Image (SDA)
					The SFC file contains reference calibration images to be used to 
					correct for the scatter and pin hole leak that occurred in Nov-92.
					The data are in the $DIR_SXT_SFC directory.
						[REF_Weekly, YDB1_Tape]
SFM	SXT FFI Monthly File (daily SFD image)			Monthly (SDA)
					The SFM file contains a single SFD image for every day of the month
					centered as close to 12:00 UT as possible.  The data are in the 
					$DIR_SXT_SFM directory.
						[YDB1_Tape]

SLS	SXT Leak Scatter Log					Weekly
					The SLS file contains information on the scattered light signal as
					seen through the narrow band filter, DPE=2, dark image.  The database
					was created after the Nov-92 entrance filter failure.  These are
					non-image data.  The data are in the $DIR_SXT_SLS directory.
						[REF_Daily, REF_Weekly, YDB1_Tape]
SLD	SXT Leak Dark Current Log				Weekly
					The SLD file contains information on the dark current signal level as
					seen in the DPE=13 dark images.  The database was created after the
					Nov-92 entrance filter failure.  These are non-image data.  The data 
					are in the $DIR_SXT_SLD directory.
						[REF_Daily, REF_Weekly, YDB1_Tape]
					

SPR 	SXT PFI Raw Reformatted Data				per Orbit (SDA)  
					The SPR file is the raw data file which contains the 
					parital-frame images.  The final SPR files are a single file per 
					orbit, but the temporary files can span more than an orbit.
					The data should be in one of the YDn data directories.
						[REF_Daily, REF_Weekly, Weekly_Tape]

SOT 	SXT Optical Telescope Log				Weekly  
					The SOT files contain the information on the location of the center 
					of the sun on the CCD, as well as the signal level detected, for 
					every complete optical image available.  This database allows the 
					tracking of the optical telescope degradation.  These are non-image 
					data.  The data are in the $DIR_SXT_SOT directory.
						[REF_Weekly, Weekly_Tape_Tar, YDB1_Tape]

SSC 	SXT Synoptic Images (centered)				Weekly (SDA)  
					The SSC files contain a narrow strip extracted from the SFD images 
					which can be processed to make a synoptic image of the sun.
					The weekly files are simply narrow strips, but the carrington
					rotation files are assembled synoptic maps.  The data are in the 
					$DIR_SXT_SSX or $DIR_GEN_SYNOPTIC directory.
						[REF_Weekly, YDB1_Tape]
SSE 	SXT Synoptic Images (east of center)			Weekly (SDA)  
					The SSE files contain a narrow strip extracted from the SFD images 
					which can be processed to make a synoptic image of the sun.
					The weekly files are simply narrow strips, but the carrington
					rotation files are assembled synoptic maps.  The data are in the 
					$DIR_SXT_SSX or $DIR_GEN_SYNOPTIC directory.
						[REF_Weekly, YDB1_Tape]
SSW 	SXT Synoptic Images (west of center)			Weekly (SDA)  
					The SSW files contain a narrow strip extracted from the SFD images 
					which can be processed to make a synoptic image of the sun.
					The weekly files are simply narrow strips, but the carrington
					rotation files are assembled synoptic maps.  The data are in the 
					$DIR_SXT_SSX or $DIR_GEN_SYNOPTIC directory.
						[REF_Weekly, YDB1_Tape]

SSL 	SXT Summary Log						Weekly  
					The SSL file contains information on the minimum, maximum, and 
					average exposure duration measured for every exposure level for 
					the week, information on the serial numbers and number of
					PFI and FFI images taken in quiet and flare mode.  It tracks
					the number of exposures through each filter and the total
					exposure through each filter.  It also has the average and
					maximum signal through the WBS-SXS, WBS-RBM, and HXT-Low
					channels.  It tracks the min, max, and avg temperature for
					the 15 SXT temperature sensors.  These are non-image data.  The 
					data are in the $DIR_SXT_SSL directory.
						[REF_Weekly, Weekly_Tape_Tar, YDB1_Tape]
SXC	SXT X-Ray Sun Center Log				Weekly
					The SXC file is simliar to the SOT file, but for X-ray images. 
					It takes each one of the SFD images and uses the routine SXT_CENTER
					to find the center of the sun.  These are non-image data.  The data 
					are in the $DIR_SXT_SXC directory.
						[REF_Weekly, YDB1_Tape]
SXL 	SXT X-Ray Histogram Log					Weekly     
					The SXL file contains a histogram for every SFD image taken.
					From the histogram, the average signal for the whole sun can be
					calculated and the solar flux can be plotted for the whole mission.
					These are non-image data.  The data are in the $DIR_SXT_SXL directory.
						[REF_Weekly, YDB1_Tape]
SXA	SXT X-Ray Average					Weekly
					The SXA file contains the average flux for 50 vertical bands
					from the SFD images.  This database can be used to evaluate
					the amount of X-ray dose the CCD is exposed to as a function
					of postion E-W.  These are non-image data.  The data are in the 
					$DIR_SXT_SXA directory.
						[REF_Weekly, YDB1_Tape]

WDA 	WBS Raw Reformatted Data				per Orbit     
					The WDA files contain the pulse count (PC) as well as the pluse 
					height (PH) (spectral) data taken by the WBS instruments.  
					The data should be in one of the YDn data directories.
						[REF_Daily, REF_Weekly, Weekly_Tape]

XAD 	Exabyte ASCII Directory for Archive Tape		Weekly per Tape   
					The XAD file contains information about what data are contained
					on each Exabyte tape.  The file format is ASCII.  The data are 
					in the $DIR_GEN_XAD directory.
						[REF_Weekly, Weekly_Tape, Weekly_Tape_Tar, YDB1_Tape]
XBD 	Exabyte Binary Directory for Archive Tape		Weekly per Tape     
					The XBD file contains information about what data are contained
					on each Exabyte tape.  The file format is binary.  The data are
					in the $DIR_GEN_XBD directory.
						[REF_Weekly, Weekly_Tape, Weekly_Tape_Tar, YDB1_Tape]