Figure Interp2. Comparison of single-sample current velocity
interpolated averaged velocity measurements, from data taken at 3-Mile Slough by the ORE
7300 UVM. The upper plot shows single measurements and interpolated
average velocities; the differences are two small to see on this scale.
The middle plot shows the difference between four-point and two-point
interpolation. The difference is not great. The lower plot shows the
"error" in the single-sample current velocity with respect to the
interpolated average velocity. The dashed line shows the value of this
difference which would correspond to a timing error of one cycle for one
of the times which determine the single-sample velocity. Frequent
"cycle-jumping" would show up as
clustering of points near these lines. There is no evident clustering
of this type. However, the spread of the points about zero, which may
represent the random measurement error, is large enough to make
infrequent cycle-jumping hard to detect.