Time reversal is a promising technique for the improvement of future telecommunication systems. A better understanding of this capability requires more investigation on real channels. This paper presents a new scheme to characterize the space-time focusing characteristics of time reversal. An extensive UWB propagation experiment is reported. The method is applied to the experimental data. Different focusing parameters are computed in different configurations. In UWB SISO configuration, time reversal increases the power of the strongest path by up to 10 dB. The channel is focused in time but the delay spread parameter remains unchanged. The average size of the spot is about 3 lambda which is larger than the ideal case. The focusing spot is often directed inline with the transmitter. At 9 lambda far from the target, the received signal is reduced by up to 10 dB in NLOS.