Correlated Noise Removal
To test the CNS (correlated noise subtraction) I have used two scans of staring observations. Here is the typical sequence of steps:
ScanNum = '43128'
ScanNum = '43129'
read(ScanNum)
stat()
base(order=1)
signal()
print data.getChanListData('rms')
plotRmsChan()
flagRms(below=10) # or whatever you see.
flagRms(above=400)
data.plotFFT(logX=0,logY=1)
skynoise(ScanNum=ScanNum,ChanRef=10,radius=0, plot=1)
signal()
# Now taper the higher noise frequencies:
data.plotFFT(logX=0,logY=1)
data.blankFreq(above=45.5,below=47.3) # cuts out a line
data.taperFreq(above=20.,N=4) # Butterworth taper. N is the steepness of the taper.
data.plotFFT(logX=0,logY=1,overplot=1,ci=3)