detectiion max on the interferomet

’m doing some research on different types of interferometry.
I encountered one called SqueeSAR, which is a combination of PSI and SBAS.
As far as i can read, it can only detect changes in terrain that is less than 2,8 cm / year, because it is the wavelength divided by 2.

Is there also such a maximum using differental interferometry? Lets say i wanted to detect some changes that are bigger, and i dont need to be that precise.

Best regards