slide 53

There are problems with the unwrapped interferograms due to discontinuities in the wrapped regions. These discontinuities are called unwrapping errors. The assumption is that the phase difference between nearby pixels is less than pi, but if there is a lot of noise, this assumption can be broken. This leads to discontinuities in the wrapped interferograms. Noisy data is typically caused by decoherence. Large displacements, like surface breaking faults, can also cause discontinuities. It's important to consider what is causing the discontinuities, whether it is displacement or noise. However, you can observe some problems in the unwrapped interferograms. There are many discontinuities in the wrapped regions. The discontinuities are called unwrapping errors. The assumption of the unwrapping is that the phase difference among nearby pixels are less than pi. However, if a data contains lots of noise due to decoherence, it can break the assumption. The consequence is the discontinuities in the wrapped interferograms. In general, the cause of noisy data is the decoherence. I will introduce the concept later. In reality, some large displacements, such as surface breaking faults, may also cause discontinuities. So, we have to think about what causes the discontinuities. Maybe it is caused by the displacement of interest rather than noise.