This will count as one of your downloads.
You will have access to both the presentation and article (if available).
A MWIR thermal imager [2] with a 1280x1024 MWIR detector and an optical zoom range between 1.2° and 20° horizontal fields of view provides a HD-SDI video stream in the 720p or 1080p standard. A camera build in software image stabilizer and a smart tone mapping algorithm improves the reconnaissance results for the observer.
A combined camera covers the visible, NIR and SWIR spectral range [3] using a common entrance optics. The resolution of the color camera Si-CMOS chip is 1920x1080 and of the InGaAs focal plane array it is 640x512 detector pixel. The combined VIS/NIR/SWIR camera provides improved ranging under hazy and misty atmospheric conditions and also improved detection of laser spots e.g. of the integrated laser designator with high sensitivity in the spectral range between 450 nm up to 1700 nm, most of the military lasers are operating in the NIR and SWIR spectral band [3]. The combination of the sensors in the platform improves significantly the operational use. The application of the described platform is not limited to military scout vehicles, the available sensors are also integrated in a targeting platform with similar performances but other environmental demands.
The possibilities, improvements in comparison of existing platforms and potential upgrades are discussed.
The multispectral sensor suite consists of a HD-TV camera sensitive in the visible (VIS) spectral range and a short wave infrared ( SWIR) camera channel in combination with an integrated laser range finder all through one common entrance pupil. The sensor suite is developed for long ranging surveillance applications.
A significant reduction of the noise equivalent irradiance (NEI) of the SWIR imager in the multispectral VIS/SWIR sensor suite has been reached by a pitch reduction and corresponding optics F-number reduction of the SWIR channel. The pitch has been reduced from 20μm to 15μm and the F-number from F/7.0 to F/5.25, respectively. The visible channel has a F-number of F/2.6 with a 11- times optical zoom and provides the same field of view and focus position as the SWIR camera with the reduced pitch. The contributions from the pitch dependent dark current and read out noise levels in combination with the reduced F-number, increasing the resulting signal to noise ratio (SNR), are discussed.
The optical design of the SWIR imaging path has been significantly improved with respect to the resulting modulation transfer function (MTF) performance, resulting in an improved resolution with respect to the initial configuration [1,2]. The optical coating designs of the two multispectral beam splitters for the separation of the visual (450nm – 680nm) from the SWIR spectral wavelength range (900nm – 1700 nm) and the separation of the included laser rangefinder (LRF) receiver channel at 1.57nm center wavelength have been improved with respect to the optical imaging performance. First electro-optical results of the improved multispectral sensor suite are discussed and compared with the original design.
The reasons why the output technique in the thermal world stayed unchanged over such a long time are: the very conservative view of the military community, long planning and turn-around times of programs and a slower growth of pixel number of TIs in comparison to consumer cameras. With megapixel detectors the CCIR output format is not sufficient any longer. The paper discusses the state-of-the-art compression and streaming solutions for TIs.
View contact details
No SPIE Account? Create one
