slide 54

The speaker discusses the process of converting the phase of displacement in an interferogram. They explain that the direction is usually converted from satellite to ground, as it is easier to interpret. However, different software packages may have their own preferences, so it's important to read their manual to avoid confusion. After we unwrap the interferogram, we usually convert the phase to displacement. The formula is just the inverse of the phase of displacement. We usually convert the direction from satellite to ground to ground to satellite, because it is more intuitive to interpret. For example, if you use INSAR to measure an off-lift surface, the interferogram shows a downward pattern because the off-lift surface causes a shortened delta range in the direction of the satellite to the ground. Sometimes it is confusing, so we usually add a minus sign to convert it to ground to satellite. Nonetheless, different software packages may have their preference. Maybe the unwrapped interferogram is converted to ground to satellite. You should carefully read their manual to avoid confusion.