SUPLANE - create common offset data file with up to 3 planes

suplane [optional parameters] >stdout

Optional Parameters:
npl=3 number of planes
nt=64 number of time samples
ntr=32 number of traces
taper=0 no end-of-plane taper
= 1 taper planes to zero at the end
offset=400 offset
dt=0.004 time sample interval in seconds
...plane 1 ...
dip1=0 dip of plane #1 (ms/trace)
len1= 3*ntr/4 HORIZONTAL extent of plane (traces)
ct1= nt/2 time sample for center pivot
cx1= ntr/2 trace for center pivot
...plane 2 ...
dip2=4 dip of plane #2 (ms/trace)
len2= 3*ntr/4 HORIZONTAL extent of plane (traces)
ct2= nt/2 time sample for center pivot
cx2= ntr/2 trace for center pivot
...plane 3 ...
dip3=8 dip of plane #3 (ms/trace)
len3= 3*ntr/4 HORIZONTAL extent of plane (traces)
ct3= nt/2 time sample for center pivot
cx3= ntr/2 trace for center pivot

liner=0 use parameters
= 1 parameters set for 64x64 data set
with separated dipping planes.

Credits:
CWP: Chris Liner

Trace header fields set: ns, dt, offset, tracl