Self-contained, eye-safe laser radar using an erbium-doped fiber laser

An Eye-safe Laser Radar has been developed under White Sands Missile Range sponsorship. The SEAL system, the Self-contained Eyesafe Autonomous Laser system, is designed to measure targetposition within a 0.5 meter box. Targets are augmented with Scotchlite for ranging out to 6 kin and augmented with a retroreflector for targets out to 20 kin. The data latency is less than 1.5 ms, and the position update rate is 1 kHz. The system is air-cooled, contained in a single 200 lb, 6-cubic-foot box, and uses less than 600 watts of prime power. The angle-angle-range data will be used to measure target dynamics and to control a tracking mount. The optical system is built around a diode-pumped, erbium-doped fiber laser rated at 1.5 watts average power at 10 kHz repetition rate with 25 nsec pulse duration. An 8 inch-diameter, F/2.84 telescope is relayed to a quadrant detector at F/0.85 giving a 5 mrad field of view. Two detectors have been evaluated, a Germanium PIN diode and an Intevac TE-IPD. The receiver electronics uses a DSP network of 6 SHARC processors to implement ranging: and angle error algorithms along with an Optical AGC, including beam divergence / FOV control loops. Laboratory measurements of the laser characteristics, and system range and angle accuracies will be compared to simulations. Field measurements against actual targets will be presented.