Buried small targets usually have a very low signal-to-noise ratio(SNR) in a single frame image obtained by the vehicle-mounted forward-looking ground-penetrating imaging radar(VFGPIR) system.This will lead to poor detection performance of the single image.One special property of a forward-looking detection system is that the same spatial location is usually observed for multiple times

each at different sand-off distances

as the vehicle moves ahead.Thus a non-coherent range multi-look accumulation method is presented by exploiting the sequence image obtained by VFGPIR in this paper.The range multi-look processing can be achieved on line by using the distance sub-band partition and iterative operation techniques.The relationship of detection probability

false alarm probability and SNR between the multi-look image and the single image is derived

and the formulation to determine the accumulative frame number is given.Experimental results of the real data show that the SNR of targets is obviously improved and the speckle is also well suppressed after the multi-look processing.Moreover

the proposed approach can obviously improve the quality of image and the detection performance while having a relatively small computational load.