Are there any methods to make terrain correction of UAVSAR phase image?

[ShenJoe]

Hello everyone, I would like to use the UAVSAR phase image to do some research on classification. I decomposed the *.dat to phase and amplitude, but they are all slant image. I have tried to use SNAP, PolSARPro to make terrain correction, but failed. I also tried isce2, but didn't find corresponding function. Could anyone give me some advice? Thank you!