Analysis, Based On Interferometric Sar Data Dem Generation And Accuracy

The fact tha INSAR data can be used to obtain DEM has been proved inthe twle of l980's. Its characteristics are: day/night and all weatherobsefVatiofl. covering moSt pan of the eath surface, all the data are basedon the same coordinae systeIn, daa precision is unified, and InaPpingPeriOd is short. Recently INSAR technolOgy has been developed veryquickly And it has been PrOved that: it is feasible to utilise rePeat-OrbitSatellite bome INSAn data to Inake toPOgraPhic maPping, bu there arequite a lot conStraints, especially the correlation will decline greatlybecause of the difference caused by repeat orbit photograPhy of thesam area.The paPer focuses on the princiPles and methods to obtain DEM on thebasis of acquiring absokite phase of mSAR data and analyzes theobtained DEM precision based on both theory and exPeriment. The maincontents are as followin:l. To obtain radar exterior orientatinn elemellts by using known groUndcofitrolling points and resolve KOnecny equivaleflt collinear eqwtinn;comPute the eleVainn of groUnd points and generate digital terrainmodel.2. To acquire 3D coordinaes of radar's haaging line through orbitalparameters of radar Providing tha radar Station's coordinates arealready known, 3D coordinaes of groUnd POints can be comPateddirectly according to slant range conditions and zero-Dopplerconditinn. and then digital terrain model can be generated.3. To analyze the factors rmuencing DEM precision theoretically basedon elevaiOn comPutation equaion and radar haging characteristics.4. To comPare the DEM ()btained by different methods and localoriginal DEM, and analyze DEM precision.