The optical scanning technology in an airborne scanning laser ranging-imager sensor

The Airborne Scanning Laser Ranging-Imager Sensor (ASLRIS) is a new generation of remote sensing and mapping system to acquire 3D geosciences information which integrates the laser altimeter, IR imager, DGPS and inertial reference system, by which a digital elevation model and georeferenced image can be generated quickly and effectively without ground control point. The GPS solution of the critical positioning problem gives high accuracy potential. The high repetitive pulse lasers give clearly recordable return signals after diffusion and reflection on the ground. Precise kinematics positioning of the platform by DGPS and inertial attitude determination by IMU provide the accurate reference to an external coordinate. The passive scanning imager, which shares the telescope and the scanning mirror with the active laser ranger, provides the infrared image. A suitable optical scanning technology is important to satisfy the demand of high-speed scanning and high-resolution laser ground sampling with limited repetitive rate of laser. Two scanning optic-mechanisms are developed and applied in the ASLRIS in sequence.