;--------------------------------------------------------------------------- ; Document name: get_obs_date.pro ; Created by: Liyun Wang, GSFC/ARC, September 21, 1994 ; ; Last Modified: Wed Apr 19 19:05:26 1995 (lwang@achilles.nascom.nasa.gov) ;--------------------------------------------------------------------------- ; FUNCTION leapsec_1972, today ; PURPOSE: ; Returns the leap seconds to be inserted when converting to TAI ; ; CALLING SEQUENCE: ; Result = leapsec_1972(today) ; ; INPUTS: ; TODAY - Modified Julian Day number ; ; RESTRICTIONS: ; Not valid for dates before 1 January 1972. ; ; This procedure requires a file containing the dates of all leap ; second insertions starting with 31 December 1971. This file ; must have the name 'leap_seconds.dat', and must be in the ; directory given by the environment variable TIME_CONV. It must ; be properly updated as new leap seconds are announced. ; ; SIDE EFFECTS: ; If the given MJD is not in the range contained in the file ; 'leap_seconds.dat', the leap second of the last entry in the file is ; returned ; IF N_ELEMENTS(today) EQ 0 THEN MESSAGE, 'Usage: result=leapsec_1972(mjd)' filename = find_with_def('leap_seconds.dat','TIME_CONV','') IF filename EQ '' THEN BEGIN MESSAGE, 'Unable to open "leap_seconds.dat". Check environment ', /cont MESSAGE, 'variable TIME_CONV and the existence of the file.' ENDIF OPENR,unit,filename,/GET_LUN mjd0 = 0l & sec = 0l & sec_sv = 0l WHILE NOT EOF(unit) DO BEGIN READF,unit, mjd0, sec IF mjd0 GT today THEN BEGIN ;--------------------------------------------------------------------------- ; The previous entry is what's needed. Terminate the loop and return ;--------------------------------------------------------------------------- CLOSE, unit & FREE_LUN, unit RETURN, sec_sv ENDIF sec_sv = sec ENDWHILE CLOSE, unit & FREE_LUN, unit ;--------------------------------------------------------------------------- ; If this point is reached, the leap second from the last entry is returned ;--------------------------------------------------------------------------- RETURN, sec_sv END FUNCTION sec2tai, second ; PURPOSE: ; Convert time in seconds since 01/01/70 00:00 into TAI ; ; EXPLANATION: ; CDS routine TAI2UTC requires that time be represented in seconds ; from midnight January 1, 1958. Observation times given in FITS headers ; of many image files are given in seconds since 1970/01/01 00:00. So ; there is a 12 year (or 378691200 seconds) difference between the two ; system. Further more, there can be several leap seconds needed to be ; added to correctly convert time into TAI. This routine calls ; LEAPSEC_1972 to get the leap second and then returns the correct TAI. ; ; CALLING SEQUENCE: ; Result = sec2tai(time_in_sec) ; ; INPUTS: ; time_in_sec - Time in seconds since 01/01/70 00:00 ; ; CALLS: ; LEAPSEC_1972 ; sec_19700101 = DOUBLE(second) ;--------------------------------------------------------------------------- ; MJD for January 1, 1970 is 40587 ;--------------------------------------------------------------------------- mjd = 40587l+LONG(sec_19700101/86400.d0) sec_19580101 = sec_19700101+DOUBLE(378691200) sec = leapsec_1972(mjd) tai = DOUBLE(sec_19580101+sec) RETURN, tai END FUNCTION GET_OBS_DATE, header, quiet=quiet ;+ ; PROJECT: ; SOHO - CDS ; ; NAME: ; GET_OBS_DATE() ; ; PURPOSE: ; Get date and time of obs. from FTIS header in CCSDS format. ; ; EXPLANATION: ; Make effort trying to extract date and time of observation from the ; header of FITS image file. It searches for the following keywords ; in the FITS header: ; ; DATE_OBS -- in CCSDS format (a keywork proposed for the SOHO ; project) ; DATE-OBS -- in DD/MM/YY format. If not present, current date will ; be returned, and a warning message is issued. ; TIME-OBS -- in hh:mm:ss format. If not present, current time will ; be returned, and a warning message is issued. ; UTSTOP -- in seconds from 01/01/70 00:00 ; UTSTART -- in seconds from 01/01/70 00:00 ; ENDTIME -- in seconds from 01/01/70 00:00 ; STARTIME -- in seconds from 01/01/70 00:00 ; YEAR -- Year number ; MONTH -- Month of year ; DAY -- Day of month ; HOUR -- Hour of day ; MINUTE -- Minute of hour ; SECOND -- Second of minute ; ; CALLING SEQUENCE: ; GET_OBS_DATE, header, utc ; ; INPUTS: ; HEADER -- Header of a FITS file ; ; OPTIONAL INPUTS: ; None. ; ; OUTPUTS: ; UTC -- String of date and time of observation in CCSDS format ; ; OPTIONAL OUTPUTS: ; None. ; ; KEYWORD PARAMETERS: ; QUIET -- Suppress any error message if set. ; ; CALLS: ; DATATYPE, NUM2STR, DMY2YMD, FXPAR, TAI2UTC, GET_UTC, SEC2TAI, REPCHAR ; ; COMMON BLOCKS: ; None. ; ; RESTRICTIONS: ; None. ; ; SIDE EFFECTS: ; None. ; ; CATEGORY: ; Science planning ; ; PREVIOUS HISTORY: ; Written September 21, 1994, by Liyun Wang, GSFC/ARC ; ; MODIFICATION HISTORY: ; Liyun Wang, GSFC/ARC, September 27, 1994 ; Added keyword QUIET. ; Liyun Wang, GSFC/ARC, October 7, 1994 ; Added checkings for image files from Mees SO ; Version 2, Liyun Wang, GSFC/ARC, December 21, 1994 ; Made it work with data from Mt. Wilson ; Version 3, Liyun Wang, GSFC/ARC, April 19, 1995 ; Made it capable of dealing with time format of HH.MM.SS ; ; VERSION: ; Version 3, April 19, 1995 ;- ; ON_ERROR, 2 IF N_PARAMS() NE 1 THEN BEGIN PRINT, 'GET_OBS_DATE -- Syntax error.' PRINT, ' Usage: Result = GET_OBS_DATE(header)' PRINT, ' ' RETURN, -1 ENDIF IF datatype(header) NE 'STR' THEN BEGIN IF NOT KEYWORD_SET(quiet) THEN BEGIN PRINT, 'GET_OBS_DATE -- Input parameter has to be of string ' + $ 'type.' PRINT, ' ' ENDIF !err = -1 RETURN, !err ENDIF ;--------------------------------------------------------------------------- ; First check the DATE_OBS keyword ;--------------------------------------------------------------------------- date_obs = fxpar(header,'DATE_OBS') IF !err NE -1 THEN RETURN, date_obs ;--------------------------------------------------------------------------- ; Check the ENDTIME and STARTIME keywords (available in KPNO He I 10830 A ; image data ; ;--------------------------------------------------------------------------- end_obs = fxpar(header,'ENDTIME') IF !err NE -1 THEN BEGIN ; Time is given in sec since 01/01/70 00:00 untime = sec2tai(end_obs) date_obs = tai2utc(untime,/ecs) RETURN, date_obs ENDIF start_obs = fxpar(header,'STARTIME') IF !err NE -1 THEN BEGIN ; Time is given in sec since 01/01/70 00:00 untime = sec2tai(start_obs) date_obs = tai2utc(untime,/ecs) RETURN, date_obs ENDIF ;--------------------------------------------------------------------------- ; Date and time have to be resolved separately. Let's get date first ;--------------------------------------------------------------------------- ;--------------------------------------------------------------------------- ; Check DATE-OBS keyword (available in LEAR H alpha image data) ;--------------------------------------------------------------------------- date = fxkvalue(header,['DATE-OBS','DATE','DATEST']) IF !err NE -1 THEN BEGIN ; Found DATE-OBS keyword ;---------------------------------------------------------------------- ; Be careful: Data from Mt. Wilson uses the mm-dd-yy format! We have ; to check that ;---------------------------------------------------------------------- mwo = fxpar(header,'ORIGIN') IF !err NE -1 AND STRUPCASE(mwo) EQ "MT. WILSON" THEN BEGIN mm = STRMID(date,0,2) dd = STRMID(date,3,2) yy = STRMID(date,6,2) date = dd+'-'+mm+'-'+yy ENDIF date = dmy2ymd(date) IF date NE -1 THEN GOTO, time_str ENDIF ;--------------------------------------------------------------------------- ; Image files from Mees Solar Observatory have separate key words for date ; and time (they all are of integer type) ;--------------------------------------------------------------------------- year = fxpar(header,'YEAR') IF !err NE -1 THEN BEGIN IF year LT 100 THEN year = year+1900 month = fxpar(header,'MONTH') day = fxpar(header,'DAY') date = num2str(year)+'/'+num2str(month)+'/'+num2str(day) GOTO, time_str ENDIF ;--------------------------------------------------------------------------- ; Give up. Use the current system date and time ;--------------------------------------------------------------------------- get_utc, date_obs,/ecs PRINT, 'GET_DATE_OBS -- Assume current system date ('+date+').' RETURN, date_obs time_str: time = fxkvalue(header,['TIME-OBS','UTSTOP','TIMEST']) IF !err NE -1 THEN BEGIN ;--------------------------------------------------------------------------- ; Check if the time is given in HH.MM.SS format (FITS files from MLSO at ; HAO are of this format) ;--------------------------------------------------------------------------- tmp = str_sep(time,'.') IF N_ELEMENTS(tmp) NE 3 THEN RETURN, date+' '+time time = repchar(time,'.',':') RETURN, date+' '+time ENDIF ;--------------------------------------------------------------------------- ; Wt. Wilson's time is given by TAVG-UT keyword, and is in decimal hours ;--------------------------------------------------------------------------- hour = fxpar(header,'TAVG-UT') IF !err NE -1 THEN BEGIN ihour = FIX(hour) min = 60.0*(hour-ihour) imin = FIX(MIN) sec = 60.0*(MIN-imin) time = num2str(ihour)+':'+num2str(imin)+':'+num2str(sec,FORMAT='(f6.3)') RETURN, date+' '+time ENDIF ;--------------------------------------------------------------------------- ; Try Mees SO format ;--------------------------------------------------------------------------- hour = fxpar(header,'HOUR') IF !err NE -1 THEN BEGIN minute = fxpar(header,'MINUTE') second = fxpar(header,'SECOND') IF datatype(second) EQ 'STR' THEN second = 0 RETURN, date+' '+num2str(hour)+':'+num2str(minute)+':'+num2str(second) ENDIF ;--------------------------------------------------------------------------- ; Give up. Use the current system time ;--------------------------------------------------------------------------- bb = str_sep(systime(),' ') time = bb(3) PRINT, 'GET_DATE_OBS -- Assume current system time ('+time+').' RETURN, date+' '+time END ;--------------------------------------------------------------------------- ; End of 'get_date_obs.pro'. ;---------------------------------------------------------------------------