The surface of a region under radar analysis, being possibly irregular, poses a challenge to many Ground Penetrating Radar (GPR) imaging techniques. This article describes different advances in the reconstruction of the subsurface electromag- netic reflectivity using an airborne GPR collecting a synthetic hologram. The approaches presented use explicit knowledge of the surface’s geometry, acquired using complementary laser technologies, in order to include it in inversion schemas using a reconstructed and interpolated hologram structure obtained from the synthetic radar data. These schemas allow for the reconstruction of the subsurface electromagnetic reflectivity in regions with irregular surfaces using radar data acquired from airborne radars. Results for different scenarios and reconstruc- tion schemas are presented using simulated data and real data acquired with a prototype of an airborne radar.