In this paper, different techniques for SEM poles estimation from the scattered response of an object are explored. Cauchy method and Matrix Pencil are widely used within this field, whereas Vector Fitting method is not often deployed for radar applications. Consequently, we evaluate the accuracy of these techniques applied to the simulated back-scattered response of a PEC sphere and a thin wire for both noisy and noiseless environments, where the precision is based on theoretical poles of each object. To do so, first on PEC sphere, we compute theoretical natural resonant frequencies and set them as references. Then, we apply SEM methods and confront their estimated SEM poles with these reference poles under different SNRs or phase errors. Second, we evaluate these methods on the thin wire by adopting the same approach. Thereby, we conclude about poles estimation precision and robustness of each method when applied to scattered field by canonical objects.