A path loss and fading model for RSSI-based localization in forested areas

Location-awareness is a prerequisite for many applications, today. Demanding applications, e.g. wildlife monitoring, rely on precise location information. A prospective approach tracking tiny lightweight animals is to capture field-strength measurements utilizing a wireless sensor network. Apriori knowledge of propagation channel characteristics is essential for precise localization. Hence, in this paper a channel model for forested areas is proposed. Therefore, a reference set of field-strength measurements has been evaluated and a channel model has been derived from these measurements. Besides path loss and fading, also cross fading between two directional antennas has been characterized. Cross-fading between these antennas is crucial for RSSI-based direction finding by directional antennas. Furthermore, the impact of incorrect modeling measurement uncertainties on the position estimation error is assessed.