A Concise Derivation of Flat Earth Effect and Terrain Height Effect for Across-track InSAR

Based on the spatial geometry relationships, a concise derivation of the flat earth effect and the terrain height effect is illustrated for across-track InSAR systems. The interferometric phase can be expressed in the form of a sum of these two kinds of effects through the derivation. The influences of the flat earth and the terrain height to the interferometric phase are simulated, which are in accordance with the theoretical analysis. The flat earth effect and the terrain height effect for distributed SAR systems are also discussed.