Error bars are plus/minus
one standard deviation
Error bars on individual observations
= formal-error x scale-factor.
Currently the scale-factors are:
N:3.0, E:4.0, U:3.0
Vel-stddev = sqrt(WN**2+RW**2)
where WN is a white noise contribution
from propagating the error bars
on the observations
and RW is a random walk contribution
(= a*sqrt(timespan)/timespan
where a is 0.001 m/yr**1/2)
U.S. Geological Survey, Earthquake Hazards Program
URL http://quake.wr.usgs.gov/research/deformation/gps//Mckenzie/walt.qoca/index.html
Contact:wprescott@usgs.gov
Last modification: 2001/11/27-14:48:14
