Surface change with multitemporal L1-data

Hello everybody,
i am new with the processing of Sen1-data. My final objectiv is to calculate a spatial change of multitemporal datsets.
i know that i have to cross-correlate two time-variant scenes, but wich process is able to calculate the spatial change of the surface in respect of the pixels greyvalue?
So that i finally get a kind of vector map or a displacement map, that shows me how much the surface of same area has changed between two dates.
I tried “changedetection”, but the value, wich was calculated, gives me no information about the direction of change.
Is there a possibility to solve my issue?
Thanks for help.