Benefits of a
Thermal Camera Shutter DRS Technologies, Network and Imaging Systems Group
DRS Networking Imaging Systems White Paper
Benefits of a
Thermal Camera Shutter – DRS Technologies, Network and Imaging Systems Group DRS Technologies provides highquality thermal imagery by integrating a shutter into each of its cameras and sensor modules. In thermal cameras, the shutter is used as a reference to perform periodic calibrations of the detector in order to more accurately display the thermal scene. Thermal cameras generate a video image by detecting infrared energy (heat) from the scene and converting this energy into an electrical signal. When the shutter closes, it blocks the thermal energy from the scene and creates a uniform thermal reference for the detector to view. A calibration is then performed to ensure that the output of every pixel is the same when viewing this uniform reference. When the shutter is opened and the detector is once again exposed to the scene, the result is a more accurate depiction of the thermal scene. This entire calibration process happens in a fraction of a second. Pixels drift over time and behave differently in various environments, so the shutter is used
periodically—typically once every 5 to 15 minutes depending on the application. When using a camera without a shutter, the operator needs to create a uniform reference for calibration—by covering the camera with a lens cap, for instance, or swinging it upward on a gimbal to look at an internal surface. The shutter makes this calibration process faster and more convenient to execute.
DRS’ cameras utilize a small, robust, and low cost shutter that ensures the unit is working in an optimal manner. It allows the camera to calibrate in order to provide the user with the most accurate and high-quality thermal image possible.
Another option utilized by some camera providers is to include a complex algorithm in the camera to perform this calibration using information in the scene. This option is called ‘scene based non-uniformity correction (NUC).’ Industry experts have been working to implement this algorithm for many years and still struggle to have a robust solution that works in various operating scenarios. This algorithm also adds cost and power consumption to the camera core due to the extensive image processing required.
DRS RSTA, Inc. 13544 N. Central Expwy, Dallas, TX 75243, Tel. 855-230-2372 | www.drsinfrared.com This information is furnished in confidence with the understanding that it will not, without the permission of DRS Technologies, be reproduced, used, or disclosed for any purpose other than the purpose for which it was furnished. All Rights Reserved.
Approved for Release MR-2012-06-625