We processed the ascending and descending pass ASAR radar data that covers the same area using 2-pass D-INSAR technology

and got the co-seismic deformation field in LOS direction of the Bam（Iran） earthquake（Mw6.5）

which happened on Dec 26

2003

with two kinds of imaging geometry.After forward modeling of the co-seismic INSAR results using（Okada’s） elastic model in half-space

we got the geometric parameters of the seismic fault and the north-south component of the deformation field.We unwrapped the interferometric phase and computed its 3D co-seismic deformation field by combining the two kinds of imaging geometry and the north-south component from（Okada’s） model.The 3D deformation field shows typical characteristics of single right-lateral strike-slip fault.The research also shows that integration of ascending and descending pass radar data could provide effective constraints for deformation models.The Bam Co-seismic deformation field could be interpreted by the simplified 1-fault model

therefore the complex 2-fault model is unnecessary.