Dr. Jan-Erik Källhammer Profile

Dr. Jan-Erik Källhammer

Director Visual Enhancement & Cognitive Systems at Magna Sweden AB

SPIE Involvement:

Author

Area of Expertise:

Automotive Night Vision , Driver warning criteria , Pedestrian Detection

Websites:

Company Website

Publications (7)

Proceedings Article | 27 October 2010 Paper

Design and evaluation of a quantum-well-based resistive far-infrared bolometer

Per Ericsson, Linda Höglund, Björn Samel, Susan Savage, Stanley Wissmar, Olof Öberg, Jan-Erik Källhammer, Dick Eriksson

Proceedings Volume 7834, 78340Q (2010) https://doi.org/10.1117/12.865036

KEYWORDS: Bolometers, Absorption, Silicon, Quantum wells, Germanium, Semiconducting wafers, Resistance, Sensors, Temperature metrology, Far infrared

Read Abstract +

Proceedings Article | 14 May 2010 Paper

Sensor fusion to enable next generation low cost Night Vision systems

R. Schweiger, S. Franz, O. Löhlein, W. Ritter, J.-E. Källhammer, J. Franks, T. Krekels

Proceedings Volume 7726, 772610 (2010) https://doi.org/10.1117/12.855932

KEYWORDS: Sensors, Near infrared, Cameras, Night vision systems, Image sensors, Image resolution, Sensor fusion, Optical resolution, Image analysis, Far infrared

Read Abstract +

The next generation of automotive Night Vision Enhancement systems offers automatic pedestrian recognition with a performance beyond current Night Vision systems at a lower cost. This will allow high market penetration, covering the luxury as well as compact car segments. Improved performance can be achieved by fusing a Far Infrared (FIR) sensor with a Near Infrared (NIR) sensor. However, fusing with today's FIR systems will be too costly to get a high market penetration. The main cost drivers of the FIR system are its resolution and its sensitivity. Sensor cost is largely determined by sensor die size. Fewer and smaller pixels will reduce die size but also resolution and sensitivity. Sensitivity limits are mainly determined by inclement weather performance. Sensitivity requirements should be matched to the possibilities of low cost FIR optics, especially implications of molding of highly complex optical surfaces. As a FIR sensor specified for fusion can have lower resolution as well as lower sensitivity, fusing FIR and NIR can solve performance and cost problems. To allow compensation of FIR-sensor degradation on the pedestrian detection capabilities, a fusion approach called MultiSensorBoosting is presented that produces a classifier holding highly discriminative sub-pixel features from both sensors at once. The algorithm is applied on data with different resolution and on data obtained from cameras with varying optics to incorporate various sensor sensitivities. As it is not feasible to record representative data with all different sensor configurations, transformation routines on existing high resolution data recorded with high sensitivity cameras are investigated in order to determine the effects of lower resolution and lower sensitivity to the overall detection performance. This paper also gives an overview of the first results showing that a reduction of FIR sensor resolution can be compensated using fusion techniques and a reduction of sensitivity can be compensated.

Proceedings Article | 13 June 2007 Paper

Uncooled infrared bolometer arrays operating in a low to medium vacuum atmosphere: performance model and tradeoffs

Frank Niklaus, Christer Jansson, Adit Decharat, Jan-Erik Källhammer, Håkan Pettersson, Göran Stemme

Proceedings Volume 6542, 65421M (2007) https://doi.org/10.1117/12.719163

KEYWORDS: Bolometers, Readout integrated circuits, Infrared bolometers, Infrared radiation, Infrared imaging, Thermal modeling, Semiconducting wafers, Atmospheric modeling, Performance modeling, Wafer bonding

Read Abstract +

Proceedings Article | 14 May 2007 Paper

Low-cost far infrared bolometer camera for automotive use

Christian Vieider, Stanley Wissmar, Per Ericsson, Urban Halldin, Frank Niklaus, Göran Stemme, Jan-Erik Källhammer, Håkan Pettersson, Dick Eriksson, Henrik Jakobsen, Terje Kvisterøy, John Franks, Jan VanNylen, Hans Vercammen, Annick VanHulsel

Proceedings Volume 6542, 65421L (2007) https://doi.org/10.1117/12.721272

KEYWORDS: Semiconducting wafers, Bolometers, Sensors, Readout integrated circuits, Wafer bonding, Germanium, Cameras, Packaging, Quantum wells, Far infrared

Read Abstract +

Proceedings Article | 21 April 2006 Paper

Fulfilling the pedestrian protection directive using a long-wavelength infrared camera designed to meet both performance and cost targets

Jan-Erik Källhammer, Håkan Pettersson, Dick Eriksson, Stéphane Junique, Susan Savage, Christian Vieider, Jan Andersson, John Franks, Jan Van Nylen, Hans Vercammen, Terje Kvisterøy, Frank Niklaus, Göran Stemme

Proceedings Volume 6198, 619809 (2006) https://doi.org/10.1117/12.663152

KEYWORDS: Long wavelength infrared, Sensors, Germanium, Semiconducting wafers, Bolometers, Wafer bonding, Manufacturing, Cameras, Readout integrated circuits, Packaging

Read Abstract +