These _txy.txt position files were made
from shear_Firing processed sm.mat files. The
positions in the sm.mat files were
subsampled from the original
1-second GPS source.

Columns in *_txy.txt
1 - yearbase (year)
2 - decimal_day (days)Jan 1 noon UTC is 0.5
3 - longitude (degrees)
4 - latitude (degrees)


Mean and Standard deviaiton for the time interval
for this entire dataset:
Means (decimal_days, longitude, latitude): 70.0769406222 -102.995947184 -46.9987272236: 
Standard Deviations (decimal_days, longitude, latitude) 0.0450935633901 0.00294698783856 0.00552114159199: 

file sample: 

#   yearbase  decimal_day         longitude          latitude
#       year         days           degrees           degrees
        1995    90.078796        85.3931450       -29.1831800
        1995    90.078912        85.3931233       -29.1830750
        1995    90.079028        85.3931683       -29.1830017
        1995    90.079144        85.3931883       -29.1829217
        1995    90.079259        85.3932217       -29.1828733
        1995    90.079375        85.3932650       -29.1828467