In this study, we present a brief information about GPR data processing and then processing methods are proposed dedicated to false alarm reduction with varying antenna height. We used horizontal filtering in cross-track and continuous wavelet transformation for A-scan signals. Additionally, 2D Wavelets and Gabor filters are applied to the data. Comparative results are presented over real data set obtained from various buried objects. It is observed that the horizontal filtering gives satisfactory results especially in cases where there is variability in antenna height.