GPS hick-ups in 2002 data

Although we havn't yet looked at the full data set for 2002 and investigated in detail the timing information we have made some of our checks to spot abnormal delta-t's in the 620 files which were accessible during the season. Check of abnormal delta's in the selected files for 2002 data:

• As a left-over of the problems in beginning of files with file index 000 i.e. the first events of a run we see strange delta-t's between the two first events (event numbers 0 and 1). This seems to be understood in terms of a "roll-over" bug where the first event in a new run gets the time stamp from the last one of the previous run. This problem is there for all such files throughout the year.
  
  
• Occasionally but very seldom we find out-liers too far out in the tail to come from a true exponential. Those are corrected for in the live-time estimate but constitute a very minor effect.
  
  
• Occasional negative delta-t's possibly caused by switching between different GPS-clocks when quality checks fail. Those negative intervals are corrected at adjacent or nearby intervals.

 File name                 delta-t      event numbers

 ab_2002_035_5303_000    661.409523        0        1
 ab_2002_035_5304_000  77302.475867        0        1
                           0.844565      508      509
                           1.026687      565      566
 ab_2002_036_5338_000    289.222558        0        1
 ab_2002_037_5353_000   1104.675507        0        1
 ab_2002_064_5561_000    251.130683        0        1
 ab_2002_084_5603_000    530.804357        0        1
 ab_2002_085_5604_000     67.401810        0        1
 ab_2002_152_5729_000  14428.726054        0        1
 ab_2002_170_5754_000    215.462504        0        1
 ab_2002_185_5798_000  10619.987703        0        1
 ab_2002_192_5805_000   1270.442279        0        1
 ab_2002_210_5825_000     50.535754        0        1
 ab_2002_230_5846_000     50.465118        0        1
 ab_2002_238_5855_003      1.008972   180502   180503
                          -1.655274   180554   180555
                          -0.318328   180583   180584
                           1.026906   180673   180674
 ab_2002_321_5957_156      1.019790  7620632  7620633
                          -1.674592  7620691  7620692
                           0.703642  7620807  7620808
 ab_2002_329_5960_000  71520.076949        0        1
 ab_2002_333_5971_000   7942.405168        0        1
 ab_2002_340_6313_000    615.647011        0        1
                           0.342369       94       95
                           0.322427      142      143
 ab_2002_342_6436_000   1256.252712        0        1
 ab_2002_343_6482_000     64.845540        0        1
 ab_2002_350_6552_000     67.904292        0        1
 ab_2002_360_6562_000  21209.971971        0        1