Mmm.
I have asked people why and they shrug their shoulders and say , " oh , it works. " So.
Yeah.
Uh , and there 's this  I guess there 's this mysterious  I mean people who do this a lot I guess have developed little tricks of the trade. I mean , there 's  there 's this , um  you don't just subtract the  the estimate of the noise spectrum. You subtract th that times