it’s not necessarily similar, because of the different looking direction. A pixel can move away from the sensor in ascending direction while it moves towards the sensor in descending direction.
In case of straight vertical movement, thei value should be similar, but there are many cases where this is not the case, all depending on the type of deformation. We have many topics on this:
- Difference between vertical and LOS displacement
- Vertical displacement senitnel 1 interpretation
- Vertical and horizontal displacement
- The phase shift originates from horizontal or vertical displacements
Two posts with references to formulas: