slide 45

The interferometric phase, called phi, is calculated using the equation 4 pi times delta r over lambda. Delta r represents the range from the satellite to the ground. Phi includes various components such as topography, surface displacement, reference surface, topospheric phase delay, atmospheric phase delay, orbits, errors, and noise. Our main focus is on the phase related to topography and surface displacement, so we need to eliminate the other components. The interferometric phase, we call it phi, is 4 pi times delta r over lambda. Notice that delta r is in the direction of satellite to ground. It means the range r starting from the satellite. Phi consists of several components. The phase contains topography, surface displacement, reference surface, topospheric phase delay, atmospheric phase delay, orbits, errors, and noise. The phase of topography and the surface displacement are what we are interested in. So we have to remove other components.