On-vehicle multi-channel Ground Penetrating Radar is attracting much attention in infrastructure maintenance field. Besides the key benefits of highspeed 3D subsurface data acquisition, basic problems such as data discontinuity due to use of multiple antennas and sparse observation that arises aliasing have been a problem. This study proposes easily applicable but effective method to solve these problems. For the first issue, calibration in each channel was done by improved Sparse Blind Deconvolution (SBD) method proposed in previous research. It was found that disuse of low-intensity frequency band provides better estimation of transmitted waves. For the second issue, super resolution method was proposed. It interpolates zeros in between sparsely observed data and then apply synthetic aperture processing. Zero insertion is an operation that restores high frequencies, which makes it possible to restore frequency components above the Nyquist frequency under certain conditions. The method was confirmed to be effective on real data.