IEC Infrared Systems PreSCO (Pre-Shot Counter Optics)
PreSCO (Pre-Shot Counter Optics) allows friendly troops to find an enemy who is watching with a rifle scope or camera. It will enable friendly forces to find snipers and their rifle scopes.
PreSCO is a new version of a ten-year-old Army project called Narcissus. Narcissus worked by looking for laser reflections from enemy optics, including riflescopes, binoculars, and cameras. Narcissus automatically scanned for enemy optics. Once a target was found, the system used long-range cameras so the soldier could look at the target in day or night. If the soldier decided that the target was an enemy, he could find its location on a map. The Narcissus system was designed to be installed on a small tower.
PreSCO will work in much the same way as Narcissus did, but it will take advantage of lessons learned. It will use improved lasers and cameras, and will also use a lighter, more accurate positioning system than Narcissus. Most importantly, PreSCO will use more powerful computers, along with Artificial Intelligence, to better find targets automatically. The Original Narcissus System, The original Narcissus OA system, was comprised of two separately controlled payloads, the first being the detection element and the second being the interrogation/target assessment element. The detection payload utilized NIR lasers (with custom optics shaping the beam into a vertical ‘sheet’) and high speed, image intensified cameras on a rotating platform that continuously scanned for optical reflections within a specified spectral band. Once a target was detected, long-range thermal and visual imagers (mounted on an independent positioner).
We were automatically slewed to the target, allowing the operator to assess the threat and also to provide a determination of the target location. Onboard image processing provides the inherent scalability of the system; this ‘edge-based’ processing strategy means that each unit carries the data processing capacity it needs, allowing it to be scaled up to multiple sites. This system incorporated the Cursor-on-Target’ protocols, which provided a ‘plug and play’ interface with other Army systems (such as the Cerberus platform, and a wide variety of other systems), allowing Narcissus to share targeting data with them, and also allowing the Narcissus assessment imagers to respond to sensor cues from other systems. Improvements on the Proposed PreSCO System The PreSCO system uses a similar concept of operation as Narcissus, but provides a number of improvements over Narcissus due to lessons learned from the original design as well as natural improvements in sensor and computing technology in the intervening (nearly) ten years since Narcissus. PreSCO will also benefit from other development at IEC that’s happened in that duration, which will lead to tangible improvements in the system. System Configuration Unlike Narcissus, PreSCO will house the detection system on a smaller, continuously rotating stage on the top of the system; that will be mounted on a lower positioner with the assessment payloads. The new configuration will take advantage of a positioner designed for a continuously-rotating application (‘Mantis’, a panoramic thermal imager, not described in this paper). This combination, shown in Figure 1, provides several immediate advantages to the PreSCO system, compared to Narcissus. First, there will be a weight reduction by at least 100lbs; the detection system of Narcissus was side-mounted, requiring a counter weight on the other side of that positioning stage to minimize tower sway as the system rotated. Also, by centering the detection payload about the axis of rotation a counter weight is not needed reducing vibration and improving positioning accuracy. This concept was considered from for Narcissus, but the appropriate positioner wasn’t available, and was deemed to add too much time and cost to the schedule at the time, leading to the design choice of Narcissus. Single Laser Source Narcissus used multiple lasers, with separate custom optics to combine their output into a single “sheet”. This approach became necessary when early testing showed the need for additional power to meet the range requirements. A more efficient approach (with the experience from that effort) is a single, variable power laser. This simplifies the optics, and eliminates losses that were due to possible misalignments of the Figure 2: IEC’s ‘Mantis’ system. Similar to the configuration of the PreSCO system; the constantly-rotating imager on the top will be the PreSCO detection system. The imagers on the bottom positioner are used for target assessment.
This approach will simplify the thermal control of the laser, needed to stabilizing the output of the laser to the proper wavelength. Improved Sensor Performance In the time period between the design of Narcissus (2010) and the current day, improvements have been realized in intensified, high-speed cameras. Using up to date technology, improvements in sensitivity are expected to enhance range and discrimination capability of PreSCO. Enhanced Target Detection/Clutter Rejection. In the past 10 years, great advances have been made in embedded computing capabilities, and machine vision learning systems. PreSCO will take advantage of this by using an AI-based machine vision system for detecting targets and rejecting clutter. These capabilities promise to be the most significant improvement between Narcissus and PreSCO.