Flash-LADAR Inertial Navigator Aiding

GPS aided inertial systems provide relatively high accuracy position and attitude information; however, they are limited to environments where GPS signals are available. In GPS-denied areas alternative positioning methods must be sought. Flash LADAR (Laser Radar) technology consists of a relatively wide angle modulated laser emitter coupled with a focal plane array detector to create an "image" where each pixel does not only have an associated intensity value, but also a range to the object that is observed. Coupling flash LADAR information with position and attitude information allows for 3-D scene recreation. With the recent development of low-cost (<$10 k) Flash LADAR sensors, the use of such technology to aid a low-cost Inertial Measurement Unit (IMU) has become practical and of great interest. Current low-cost Flash LADAR sensors are capable of greater than 100 x 100 pixel resolution with a 5 mm depth resolution at a 30 Hz frame rate. From this high accuracy/resolution sensor data, various geometrical features in the environment can be extracted such as the planes created by walls, lines created where planes intersect, and points from the intersection of lines can be measured with high precision. In this paper we will describe the concept of a Flash- LADAR aided inertial navigator and present the results of the operation of such a system in a simulated indoor environment.