Remotely triggered solar blind signaling using deep ultraviolet (UV) LEDs

Abstract

The purpose of the triggered individual identification friend or foe (IIFF) patch is to covertly reduce fratricide incidents and provide related remotely triggered marking or signaling capability. This research extended previous work by evaluating solar blind UV light emitting diodes (LEDs). Due to the zero background condition ("solar blind") from 200 to 280 nm, use of a UV source in this 80 nm window can be used to create a triggered IIFF patch that works both day and night. Additionally, due to the strong wavelength dependence for scattering reactions in air, UV light may provide a means to accomplish non line of sight (NLOS) signaling. The goal of this research was to develop a working prototype of a triggered IIFF device that can be seen from a distance of 1 km, either day or night, and explore the possibility of using this device to perform NLOS signaling. Results will be presented demonstrating prototype performance in a field exercise, as well as the device characterization required to define and optimize the prototype design. Device characterization included measurements of LED intensity as a function of driving current and voltage and the determination of LED performance parameters outside the standard operating specifications.