UWB(Ultra Wide-Band) pulse radar is a promising candidate for surveillance systems used to prevent crimes and terror. The high-speed SEABED (Shape Estimation Algorithm based on BST and Extraction of Directly scattered waves) imaging algorithm, is deployed to apply UWB pulse radar in fields that require realtime operations. The SEABED algorithm assumes that omni-directionsl antennas am scanned to observe the scattered electric field in each location. However, for surveillance systems, antenna scanning is impractical. The instantaneous velocity of any given walking motion is an unknown variable which changes as a function of time. In our previous work, walking motion m used to replace antenna scanning by assuming a simple model of walking motion. In this paper, we measure a real walking motion and determine a realistic walking model. We investigate the performance of the proposed algorithm with this realistic model.