This paper presents a study of the sensibility of the incoherent (electromagnetic backscattering model) and coherent (DInSAR and PolInSAR inversion) crop height estimation methods of SAR imaging. The methods were compared for paddy-rice crop height monitoring with a TanDEM-X dataset. For this, rice-cultivated agricultural fields located in Northern Turkey were selected. Intensive ground data collection during the cultivation period in 2015 was carried out. The accuracy analysis showed that the requirement of external (vegetation-free) DEM in DInSAR-based crop height estimation decreases its performance compared to the PolInSAR and backscattering inversion methods.