NOTES ON PMTRAS BLIP TIMING



Establishing the time of PMTRAS blips

t0 = time (seconds relative to 1980) of the timetag of first packet.

t0 = HSI_SCTIME2ANY( indat[0].sctime_ref, /utime)

All other times are expressed relative to t0.

packetime  = time (seconds relative to t0) of subsequent packets (REAL*8)

packetime 	= HSI_SCTIME2ANY( indat[*].sctime_ref, /utime) - t0

timecntr	= array of counter values of samples (For 2ms, in range [0,127])
				timecntr[*,n] = indat[n].counter[0:255]

stime		= start time of accum interval of peak count (seconds, relative to t0)
	stime[*,n] = packetime[n] 	
				 	+ FINDGEN(256)  * readout_interval[n] 
					+ timecntr[*,n] * accum_interval[n]		; for n'th packet
	maxcase 	= WHERE(timecntr[*,n] eq max_cntr, nmax)	; ID cases where peak was in last accum
	stime[maxcase,n] = stime[maxcase,n]-readout_interval[n]  ; subtract 1 readout for pipeline corr

nsamp 	  		= 256*npackets
packetid		= INTARR(   256, npackets)				; original packet number
sampleid		= BYTARR(   256, npackets)				; sample number (0,,,255) within packet
timecntr		= BYTARR(   256, npackets)				; counter value for each sample
stime     		= DBLARR(   256, npackets)				; start time of accumulation interval identified by 'timecntr'
scval 	  		= BYTARR(3, 256, npackets)
accum_interval  = FLTARR(npackets)						; fixed accumulation inverval (seconds)
readout_interval= FLTARR(npackets)						; fixed readout interval (seconds)

;
ratio = FLOAT(counts[2,*] - counts[0,*]) / (counts[1,*] - bkgd)			; note ratio=0 if peak is at center of intval
ratio = REFORM(ratio, /OVERWRITE)
accum_intervals 	= accum_interval[packetid]
blip_interpolation 	= hsi_pmtras_blip_interpolation (ratio, accum_intervals, BLIP_FWHM = blip_fwhm, /SEQUENCED)
bliptimecorr 		=  blip_interpolation.time_correction * accum_intervals	; .time_correction values are in range [0,1]
bliptime 			= starttime + bliptimecorr