Why is interferometric coherence calculated over a window of pixels?

When calculating interferometric coherence, why can't you do so on a pixel by pixel basis? I know the equation for estimating coherence = (|S1∙S2* |)/√(S1∙S1*∙S2∙S2*) where S1 and S2 are the two...

11 November 2019 1,421 3 View