nyquist with noise

[gfds]

Hey everyone,

How can i get rid of the  noise from second view (green analysis by measure)? The data whith I measrure are two sinusoid tension and current (view 1). Frequency sweep on graphs is 19000 to 40000 Hz. We can see two resonaces from current sinusoid.     On the analysis I have automatic analyse with frequency whith i do not knew where is from (sweep is from 0 to 150000Hz and it isn't my measure sweep ?). I tried with filter but few are changing graphs. I used it maybe bad, i don't know. If someone knew the answer ?

I am working with kart usb ni 6251 and version labview 8.5.

Marek