SearchSense: Haptic Directional Guidance for Emergency Response

Urban Search and Rescue (USAR) teams lack portable, fast, and intuitive tools for locating victims in low-visibility disaster sites. Existing Direction-Finding (DF) systems are often too bulky, slow, or impractical because they require victims to have specialized transmitters. In this work, we present SearchSense, a portable device in two modalities: handheld and hands-free wearable, that provides left/right directional guidance via augmented reality and haptics to locate a victim’s cellphone. It overcomes the limitations of current systems by using an amplitude-comparison technique to detect unintentional radio frequency (RF) emissions from standard cellphones in the 2.45 GHz ISM and cellular bands, eliminating the need for any special equipment on the victim. In technical tests, SearchSense demonstrated high accuracy, achieving a 5.3° RMS Angle-of-Arrival (AOA) error in a controlled anechoic chamber and 6.8° RMS in a realistic outdoor environment with ground interference, comparable to existing AOA systems. In a user study with four USAR experts, participants found its DF vibrotactile feedback to be highly intuitive and praised its wearable design, confirming its potential to improve rescuer situational awareness and operational effectiveness. USAR feedback indicates that RF-based multimodal guidance could be a viable approach for passive DF in disaster response.