Spherical Sensor Configurations (SSC) have been designed for detecting and tracking signals in three dimensions. The Spherical Sensor Configurations offer distinct advantages over contemporary imaging systems, significantly enhancing three-dimensional (3D) situational awareness. Sensor systems utilizing a spherical geometry as a foundation (Figure 1) can be designed for a variety of applications.
A singular ring of sensors provides a basic device that can monitor sources in a two-dimensional plane. These systems calculate extremely accurate angular directions to signal sources. More sophisticated systems with full spherical sensor placement are being designed for monitoring multiple targets in any spatial orientation. Information generated from these systems can be integrated with contemporary imaging systems for further target identification. Full spherical SSC systems offer a 4 Pi steradian Field of Regard (FOR).
The underlying concept of the innovation is based upon fundamental properties of signal transmission and its reception on a spherical surface. The technology exploits the principle that a source of light will illuminate one hemisphere of a spherical object (similar to the Earth/Sun system). The significance of this concept lies in the consistent and mathematically predictable position of the illuminated hemisphere relative to the source. Harnessing this concept, a spherical receiver can be constructed with strategically placed sensors to determine the position of the illuminated hemisphere and, subsequently, the 3D direction of the source. Spherical Sensor Configurations offer distinct advantages over contemporary imaging systems in monitoring a wide FOR. SSC systems overcome imaging Field of View (FOV) limitations, enabling a single sensor system to view targets in all directions, significantly enhancing 3D situational awareness.
Spherical Detection Systems (SDS) are being designed for detecting and tracking infrared (IR) heat signatures, primarily in the 3 - 5 and 8 - 12-um thermal imaging bands. Current prototype development is in the 8 - 12-um band for detecting and tracking human and vehicle infrared (IR) targets. Analysis is being performed in the 3 - 5-um band for the detection of hotter temperature targets including missiles, RPGs, highspeed vehicles, and arms fire. The SDS can simultaneously track multiple targets in any spatial orientation, making it the ideal sensor system for Infrared Search and Track (IRST). The SDS can be fitted with sensors that can sample into the megahertz and analyzed with an onboard DSP for ultra-high-speed threat detection and tracking. The system offers continuous, passive sensing in a mechanically passive package with low power consumption. The wide FOR and high-speed sensing is well suited for capturing the location of initial launches or other incoming threats.