Rejection of first 3 readings at the morning field check-in station:
  • Some weak seismic activity somewhere on the planet made the ground
    oscillate and caused higher SD. Things settled after around a quarter-
    hour.

Regarding the 1111 tie file:
  • A virtual check-in was created for the begining of the day, because another
    gravity check-in point was used and not visited again. To do this:
      – A Δ from datum value was calculated for the check-in used at the 
        begining of the day:
          ○ station 2223
          ○ datum                          7378.533 mGal
          ○ early day value              – 5522.6110 mGal
          ○ Δ                            = 1855.922 mGal.
      – The Δ value was then subtracted from the datum of 1111 to create 
        a virtual check-in at the time of the 2223 check-in:
          ○ station 1111
          ○ datum                          7347.324 mGal
          ○ Δ                            – 1855.922 mGal    
          ○ virtual check-in             = 5491.402 mGal

Regarding the 2 xyz files:
  • The DEM covering the whole area is very large, in fact likely too large for
    the field computer used in conjunction with Gravred 3.2 (who is systematically
    loading the whole DEM to the RAM before proceeding to calculations). So in order
    to avoid errors due to lack of memory available, the inner DEM was split into
    2 files of 5.5M points each, and the results from two individual runs are added
    together to create the final xyz containing one unique inner DEM correction value.
  • The final xyz is actually a merger of all days together.