Technical note | Optoelectronic Assessment of the Estimote Location Beacon

Abstract

The Estimote Location Beacon^TM is the latest addition to the Hybrid.Beacon DST Group project. This project uses inexpensive commercial components to assess the potential for increased situational awareness in tactical scenarios. The ability of the Estimote Location Beacon to generate, and participate in a Bluetooth-based Mesh Network, along with an amazing array of on-board sensors, makes it an area of high potential for innovation. This Technical Note will focus on one of the Beacon’s sensors, its ambient light capability. The next Technical Note in this series will focus on the magnetometer.

Executive Summary

This Technical Note establishes a first-pass assessment of the effectiveness of the ambient light sensing capability of the Estimote Location Beacon. Estimote is the market leader in development of highly sensitive Internet of Things Bluetooth components. As part of an innovation initiative for modernising the Australian Defence Force, a project was formed to demonstrate a practical application of this technology. By combining an existing DST algorithm, called Hybrid Registration, with these new beacons, the Hybrid.Beacon project was started. The Hybrid.Beacon project has been running in the Australian Defence Science and Technology Group since October 2015. There are two main technological initiatives in this project. The first is an iPhone-based app that has been written to demonstrate the potential for integrating image and video information with the iPhone’s on-board sensors. The second involves exploiting these beacons to assist the soldier, or search and rescue technician, by providing enhanced situational awareness. 

As this device is being integrated into the Hybrid.Beacon project, certain tactical information may be derived from knowing ambient light. For example, if the beacon is positioned in an office, it will signal a change in ambient light when the occupant enters and turns on the office light. 

This is the first of a series of five Technical Notes assessing each of the capabilities of the beacon, the others being barometer, magnetometer, accelerometer, and temperature. Of course, the primary reason for the beacons is to potentially assist in enhancing spatial awareness in time-critical scenarios, especially when GPS-denied. This is accomplished through the Bluetooth-based mesh networking capability.

When compared to a standard light meter the Estimote Location Beacon performs well. With only a minor adjustment it is able to relay accurate illuminance (Lux) information. However, it does not respond quickly to changes in light levels, which is essential to understand prior to tactical use. This Technical Note may be republished as a Technical Report (which typically contains a higher level of technical detail and experimental rigor) once additional microprocessor level information is known about the beacon.