Laser Threat – Compact Alert Module
Compact low-cost laser warning systems are in high demand for military, commercial, and battlespace platforms as lasers become more prevalent in tactical weapon systems. Present laser warning systems (LWS) with high wavelength resolution are not compact, require bulky dispersive or multi-sensor elements, do not possess fast data collection times, or have optics/detectors that are too expensive or complicated to warrant high volume implementation.
To address the need for a compact, low-cost LWS, new techniques must be brought to bear on the optics, spectral sensing and packaging aspects of a LWS. Imaging array technology is one area that offers compelling advantages in cost, wavelength sensitivity and high data rate. In particular, CMOS sensors, when coupled with custom collection optics and on-chip spectral filtering, provide a means for simultaneous angle-of-arrival (AoA) and selective spectral characterization of threat radiation. Expansion of the RGB color filter pattern to a custom laser warning mosaic that includes filters for specific wavelengths and bands that can address the spectral resolution and breadth of laser threats is critical for an image-array-based LWS.
Nanohmics is fabricating a laser threat detection system that identifies, in real-time, the angle of arrival and spectral properties of laser threats. The system is contained in a compact package consisting of a custom low-profile optical assembly with a full-coverage field-of-view larger than one hemisphere, mapping the angle of arrival of the threat onto a low-cost CMOS image sensor that possesses a custom color filter mosaic for threat wavelength and intensity characterization.
The figure shows a schematic illustration of the proposed Laser Threat, Compact Alert Module (LT-CAM) that is presently planned for development during a Phase II SBIR program with the Air Force Research Laboratory Sensors Directorate. The LT-CAM consists of a complete warning system with a custom low profile optical assembly juxtaposed over the surface of a CMOS image sensor mounted to a circuit board with a digital signal processor (DSP). The DSP executes programming for processing image data in real-time, and determining the AoA and wavelength of multiple simultaneous laser threats. The dimensions, weight, and connectivity of the sensor will facilitate attachment to a variety of airframes, and the data interface will provide a feature set that simplifies coupling to external devices for countermeasure or threat-location purposes.