function filtdat = rsig20( nterms )
% Generate a sequence of 'nterms' filtered random numbers with flat
% band limited to the bottom 10% of the Nyquist frequency and attenuating
% significantly above 30% of the Nyquist frequency.

nfilt = 21;
nhalf = 10;
kernel= [ ...
  -1.54090222209301e-04, -1.27564482084636e-03, -3.91651490992275e-03, ...
  -7.14238759641689e-03, -6.89767692161604e-03,  3.90895844721567e-03, ...
   3.19956625938057e-02,  7.79318472157070e-02,  1.32071643271182e-01, ...  
   1.76561524519525e-01,  1.93833356847153e-01,  1.76561524519525e-01, ...
   1.32071643271182e-01,  7.79318472157070e-02,  3.19956625938057e-02, ...
   3.90895844721566e-03, -6.89767692161605e-03, -7.14238759641689e-03, ...
  -3.91651490992275e-03, -1.27564482084636e-03, -1.54090222209301e-04 ] ;

ntmp = nterms+2*nfilt-1;
rvtmp = [rand(ntmp,1)-rand(ntmp,1)];
flttmp = conv(rvtmp,kernel);
filtdat = flttmp(nfilt:nfilt+nterms-1)*sqrt(10.0);

