Laser Beamrider Detector Systems

Lasers are finding increased application in military weapon systems as a means of designating targets for guided missiles and as weapons themselves. Laser warning sensors have been developed that provide laser detection, angle of arrival, wavelength discrimination and temporal characterization of the laser source. However, there is a need to improve the threshold detection level and false alarm rate of laser warning sensors for detection of the low-intensity pulsed lasers associated with Beamrider type guided missiles. Incident power levels are as low as 1.5 x 10E-8 Watts per square centimeter, peak, with pulses whose widths range from 80 to 400 nanoseconds (producing 1.2 to 5 x 10E-15 Joule/sq.cm. per pulse), and pulse repetition rates from 8 to 30 kHz.

Under a Phase II SBIR contract from the Naval Air Warfare Center (NAWC), PSI has breadboarded and field tested a Laser Beamrider Detector System (LBRDS), suitable for aircraft, that is capable of detecting, with low false alarm rate, incident near-IR pulsed laser illumination under all ambient illumination conditions at laser pulse power levels as low as 1.5E-8 Watts per sq.cm., and 100 nanosecond pulse width.

Laser Hazard Sensor with Recorder (LHSR)

The National Institute for Occupational Safety and Health (NIOSH), the Federal Aviation Agency (FAA), and the US military aviation community are all concerned with eye hazards resulting from uncontrolled exposure of aircraft crews to laser illumination. Permanent eye damage can occur, or temporary interference with a pilot's vision may endanger the aircraft during critical landing maneuvers. There have been repeated instances where inadvertent or deliberate laser illumination has interfered with low-altitude operations of police aircraft.
Princeton Scientific Instruments has, under funding from (NIOSH), developed an electro-optical system for detecting laser radiation. The system covers a wide field of view, and detects and locates any source of laser radiation producing hazardous levels of illumination at visible and near infra-red wavelengths. It is battery powered, compact, and portable, and records for later analysis the location, wavelength, intensity, and time whenever a laser hazard is detected.
A prototype unit of the LHSR provides all of the functionality of the envisaged commercial system, including portability and operation from battery power. However, it has not been packaged for minimum size. The prototype is contained in a 7 x 7 x 2-1/2 inch case. PSI envisions that the commercial unit would be smaller than a standard VHS video cassette, compact enough to allow easy mounting in an aircraft cockpit. Figure 1 is a photograph of the prototype laser hazard sensor, with its associated readout box. (See below.)

The optical sensor employed in the LHSR is a miniature television camera. It is mounted, together with the associated analog and digital electronics, in an enclosure as shown below. Also shown is the visual display unit, which indicates the intensity of a detected laser, and its location. This unit can be separately mounted. In a future system, the sensor also could be mounted in a separate, very small, housing. It could, for instance, be configured for helmet mounting.