In this paper we consider the electromagnetic inverse scatting problem for GPR application. The reconstruction of the shape of buried dielectric objects is obtain using the well-known non iterative inverse technique entitled Linear Sampling Method (LSM). The applicability of LSM for GPR imaging is discussed, its performance with full and limited aperture is explored in a simple 2D free space configuration in a first step. The use of non-ideal sources and the possible influence of the antenna radiation pattern onto the results are considered. An enhanced approach is proposed to improve the robustness of the LSM with non-ideal sources.