MEMS barometers in a wireless sensor network for position location applications

Some of the potential applications of barometric altitude readings (derived from atmospheric pressure measurements) include, but are not limited to, floor identification inside large buildings (e.g. museums, shopping malls, etc.), fall detection of a human body in the direction of medical monitoring systems and determination of an airplane's position angles. Implementation of these pioneer applications is feasible when addressing cutting-edge equipment of high accuracy, which in this respect is the Micro- Electro-Mechanical-Systems (MEMS) sensors technology. Several applications in the literature exploit the MEMS barometric pressure sensors, found in smartphones, in order detect vertical displacement in position location applications. However, the beneficial effects of this approach are limited to the utilization of the default sensors devices found in mobile phones, with the latter being of considerable cost. This paper presents a low-cost wireless sensor network system for realtime monitoring of barometric pressure on a LabVIEW-based computer interface. The system admits up to four individual measurement devices, allowing the simultaneous evaluation of ambient air pressure in vertical displacements. The minimum hardware involvement required by the system, along with an offline analysis of the available measurement data using Matlab script code, render the proposed experimentation model a particularly helpful reference guide to the implementation of position location systems and applications.