People with visual impairments face considerable limitations with their mobility, but still there is little infrastructure in place to help them. In this study, we present a new wearable electronic travel aid (ETA), “Personal Radar”, which assists blind people in navigating in indoor environments using an ultrasonic sensors. After briefly describing our initial system design, we report the improvements from the pilot study. Then, we introduce our experiment in progress. In the experiment, blind folded students and visually impaired people will navigate through a maze and an empty room based on auditory and vibrotactile feedback of the device. This system could serve as an effective research platform for obstacle detection, current location awareness, and direction suggestion for the blind.