A software application, SIST, has been developed for the simulation of the video at the output of a thermal imager. The approach offers a more suitable representation than current identification (ID) range predictors do: the end user can
evaluate the adequacy of a virtual camera as if he was using it in real operating conditions. In particular, the ambiguity in the interpretation of ID range is cancelled. The application also allows for a cost-efficient determination of the optimal design of an imager and of its subsystems without over- or under-specification: the performances are known early in the development cycle, for targets, scene and environmental conditions of interest. The simulated image is also a powerful method for testing processing algorithms. Finally, the display, which can be a severe system limitation, is also fully
considered in the system by the use of real hardware components. The application consists in Matlabtm routines that
simulate the effect of the subsystems atmosphere, optical lens, detector, and image processing algorithms. Calls to
MODTRAN® for the atmosphere modeling and to Zemax for the optical modeling have been implemented. The realism of the simulation depends on the adequacy of the input scene for the application and on the accuracy of the subsystem
parameters. For high accuracy results, measured imager characteristics such as noise can be used with SIST instead of
less accurate models. The ID ranges of potential imagers were assessed for various targets, backgrounds and atmospheric conditions. The optimal specifications for an optical design were determined by varying the Seidel aberration coefficients to find the worst MTF that still respects the desired ID range.
In order to efficiently digitize the 3-D shape of objects in applications such as quality control, reverse engineering and inspection, a flexible system based on a portable range sensor coupled to an optical tracking device has been developed. The hand-held range sensor can be moved freely in space without the constraint on motion imposed by a translation or rotation system. An optical tracking device synchronized with the sensor is used to compute the sensor's orientation and location in real-time. The optical tracking and the integration of a 3-D range sensor with a positioning device for manual scanning constitute the two major challenges of the proposed system. This paper first presents the range sensor and the optical tracking system. The main aspects including the calibration approach and the sensor integration are described in the following sections. An error analysis has been conducted to predict the expected results. Finally, experimental results are presented to validate the overall system.