If you type these commands:
f = midigui()
tag = 'hd107446'
oir1dcompressdata,f,getenv('prismhmask'),tag
d = getoirdata(tag+'.compressed.fits')
plot,d[500:900].data1[100]
You will get this:
You can subtract the data in the two interferometric channels:
plot,d[500:900].data1[100] - d[500:900].data2[100]
The result looks like this:
