LITE Clock Drift

Time correction for LITE high rate data.  Time correction was applied to LITE high rate 
data obtained real-time during the mission. 

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1.  Start with first recorded LITE time and GMT time:

           LITE start time = 253/2:49:36.99
 
                lite_start = 253.d0 * 86400.d0 + 2.d0 * 3600.d0 + 49.d0 * 60.d0 + 36.99d0
                           = 21869376.990 seconds

           LITE end time   = 262/5:44:19.19
    
                lite_end   = 262.d0 * 86400.d0 + 5.d0 * 3600.d0 + 44.d0 * 60.d0 + 19.19d0
                           = 22657459.190 seconds
 
     lite_start - lite_end = 788082.20 seconds (lite_del)
 
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            GMT start time = 253/2:49:37.549
 
                 gmt_start = 253.d0 * 86400.d0 + 2.d0 * 3600.d0 + 49.d0 * 60.d0 + 37.549d0
                           = 21869377.549 seconds
 
            GMT end time   = 262/5:44:26.063
 
                 gmt_end   = 262.d0 * 86400.d0 + 5.d0 * 3600.d0 + 44.d0 * 60.d0 + 26.063d0
                           = 22657466.063 seconds
 
       gmt_start - gmt_end = 788088.514 seconds (gmt_del)

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        gmt_del - lite_del = 788088.514 - 788082.2 
                           = 6.314 seconds

    gmt_start - lite_start = 0.559

          total time drift = 6.314 + 0.559 
                           = 6.873 seconds
    
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2.  compute a scale factor to correct all time parameters (eds interrupt, ddhu interrupt, aoe interrupt).

              scale_factor = 1.0 - (gmt_del/lite_del)
                           = 8.0118546d-06

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3.  For each time to correct, (for example, eds interrupt time)

               eds_seconds = float(i_gdd)*86400.d0 + float(i_ehh)*3600.d0 + float(i_emm)*60.d0 + f_ess
            eds_correction = ((eds_seconds - lite_start) * scale_factor) + .559
             corrected_eds = eds_seconds + eds_correction

                  + the initializing of the software timer.