SHIFT PLOT:


     The shift plot  is a graph  of elevations for the the [8, 12, 16, 20, ..., 44,  48,  52,  56]
cross-sweep positions.  The elevations at position 8 are plotted versus the along-track sequence
or line sweep number.  This gives a sort of "time series of elevations at the cross-sweep position
8 as the plane flies along.  The elevations at cross-sweep position 12 are plotted similarly on the
same graph, except their elevations all are increased by 5 meters.  This shifts the position 12 time
series slightly above the position 8 time series.  The graph of the position 16 time series is also
graphed on the same axis with an increase in elevation of 10 meters. This is done with all 13
cross-track positions.  The elevations values used in these shift plots are the original values from
the Walsh data with no prior smoothing, clipping or editing.  The graphs show all the faults and
problems of the original data set.

     The shift plot also has graphs of the x- and y-positions of the cross-sweep elements as the
plane flies along.  The two shift plots corresponding to the outlier plots previously discussed are
also attached.  These "path" graphs give fairly clear indications if the plane takes a violent roll or
experiences strong lateral displacement.