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Grönwall, ChristinaORCID iD iconorcid.org/0000-0002-4434-8055
Alternative names
Publications (10 of 31) Show all publications
Grönwall, C., Tolt, G., Larsson, H., Lif, P., Bissmarck, F., Tulldahl, M., . . . Thorstensson, M. (2015). 3D sensing and imaging for UAVs: Invited paper. In: Proceesings of SPIE: . Paper presented at Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX Gary Kamerman; Ove Steinvall; Keith L. Lewis; John D. Gonglewski Toulouse, France | September 21, 2015. , 9649
Open this publication in new window or tab >>3D sensing and imaging for UAVs: Invited paper
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2015 (English)In: Proceesings of SPIE, 2015, Vol. 9649Conference paper, Oral presentation with published abstract (Refereed)
Keywords
3D data, UAV, target detection, mapping
National Category
Signal Processing
Identifiers
urn:nbn:se:liu:diva-128054 (URN)10.1117/12.2192834 (DOI)
Conference
Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX Gary Kamerman; Ove Steinvall; Keith L. Lewis; John D. Gonglewski Toulouse, France | September 21, 2015
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2016-08-31
Grönwall, C., Hendeby, G. & Kristian, S. (2015). A proposal for combining mapping, localization and target recognition. In: Gary Kamerman; Ove Steinvall; Keith L. Lewis; John D. Gonglewski (Ed.), ELECTRO-OPTICAL REMOTE SENSING, PHOTONIC TECHNOLOGIES, AND APPLICATIONS IX: . Paper presented at Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX France | September 21, 2015. SPIE - International Society for Optical Engineering, 9649
Open this publication in new window or tab >>A proposal for combining mapping, localization and target recognition
2015 (English)In: ELECTRO-OPTICAL REMOTE SENSING, PHOTONIC TECHNOLOGIES, AND APPLICATIONS IX / [ed] Gary Kamerman; Ove Steinvall; Keith L. Lewis; John D. Gonglewski, SPIE - International Society for Optical Engineering, 2015, Vol. 9649Conference paper, Published paper (Refereed)
Abstract [en]

Simultaneous localization and mapping (SLAM) is a well-known positioning approach in GPS-denied environments such as urban canyons and inside buildings. Autonomous/aided target detection and recognition (ATR) is commonly used in military application to detect threats and targets in outdoor environments. This papers present approaches to combine SLAM with ATR in ways that compensate for the drawbacks in each method. The methods use physical objects that are recognizable by ATR as unambiguous features in SLAM, while SLAM provides the ATR with better position estimates. Landmarks in the form of 3D point features based on normal aligned radial features (NARF) are used in conjunction with identified objects and 3D object models that replace landmarks when possible. This leads to a more compact map representation with fewer landmarks, which partly compensates for the introduced cost of the ATR. We analyze three approaches to combine SLAM and 3D-data; point-point matching ignoring NARF features, point-point matching using the set of points that are selected by NARF feature analysis, and matching of NARF features using nearest neighbor analysis. The first two approaches are is similar to the common iterative closest point (ICP). We propose an algorithm that combines EKF-SLAM and ATR based on rectangle estimation. The intended application is to improve the positioning of a first responder moving through an indoor environment, where the map offers localization and simultaneously helps locate people, furniture and potentially dangerous objects such as gas canisters.

Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2015
Series
Proceedings of SPIE, ISSN 0277-786X ; 9649
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-123215 (URN)10.1117/12.2192200 (DOI)000367451000013 ()978-1-62841-859-0 (ISBN)
Conference
Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX France | September 21, 2015
Projects
Security Link
Funder
Security Link, 1959
Available from: 2015-12-07 Created: 2015-12-07 Last updated: 2016-02-01Bibliographically approved
Grönwall, C., Gustafsson, D., Tolt, G. & Steinvall, O. (2015). Experiences from long-range passive and active imaging. In: Proceedins of SPIE: . Paper presented at Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX (pp. 96490J-1-96490J-13). , 9649
Open this publication in new window or tab >>Experiences from long-range passive and active imaging
2015 (English)In: Proceedins of SPIE, 2015, Vol. 9649, p. 96490J-1-96490J-13Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

We present algorithm evaluations for ATR of small sea vessels. The targets are at km distance from the sensors, which means that the algorithms have to deal with images affected by turbulence and mirage phenomena. We evaluate previously developed algorithms for registration of 3D-generating laser radar data. The evaluations indicate that some robustness to turbulence and mirage induced uncertainties can be handled by our probabilistic-based registration method.

We also assess methods for target classification and target recognition on these new 3D data. An algorithm for detecting moving vessels in infrared image sequences is presented; it is based on optical flow estimation. Detection of moving target with an unknown spectral signature in a maritime environment is a challenging

problem due to camera motion, background clutter, turbulence and the presence of mirage. First, the optical flow caused by the camera motion is eliminated by estimating the global flow in the image. Second, connected regions containing significant motions that differ from camera motion is extracted. It is assumed that motion caused by a moving vessel is more temporally stable than motion caused by mirage or turbulence. Furthermore, it is assumed that the motion caused by the vessel is more homogenous with respect to both magnitude and orientation, than motion caused by mirage and turbulence. Sufficiently large connected regions with a flow of acceptable magnitude and orientation are considered target regions. The method is evaluated on newly collected sequences of SWIR and MWIR images, with varying targets, target ranges and background clutter.

Finally we discuss a concept for combining passive and active imaging in an ATR process. The main steps are passive imaging for target detection, active imaging for target/background segmentation and a fusion of passive and active imaging for target recognition.

Keywords
Passive imaging, active imaging, data fusion, ATR, MWIR, SWIR, 3D data, target detection, sea vessels.
National Category
Computer Vision and Robotics (Autonomous Systems)
Identifiers
urn:nbn:se:liu:diva-128053 (URN)10.1117/12.2196278 (DOI)
Conference
Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2018-01-10
Steinvall, O., Chevalier, T. & Grönwall, C. (2014). Simulation and modeling of laser range profiling and imaging of small surface vessels. Optical Engineering: The Journal of SPIE, 53(1), 013109-1-013109-16
Open this publication in new window or tab >>Simulation and modeling of laser range profiling and imaging of small surface vessels
2014 (English)In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 53, no 1, p. 013109-1-013109-16Article in journal, Editorial material (Refereed) Published
Abstract [en]

The detection and classification of small surface targets at long ranges is a growing need for naval security. Simulations of a laser radar at 1.5 μm aimed for search, detect, and recognition of small maritime targets will be discussed. The data for the laser radar system will be based on present and realistic future technology. The simulated data generate signal waveforms for every pixel in the sensor field-of-view. From these we can also generate two-dimensional (2-D) and three-dimensional (3-D) range and intensity images. The simulations will incorporate typical target movements at different sea states, vessel courses, effects of the atmospheric turbulence and also include different beam jitter. The laser pulse energy, repetition rate as well as the receiver and detector parameters have been the same during the simulations. We have also used a high resolution (sub centimeter) laser radar based on time correlated single photon counting to acquire examples of range profiles from different small model ships. The collected waveforms are compared with simulated wave forms based on 3-D models of the ships. A discussion of the classification potential based on information in 1-D, 2-D, and 3-D data separately and in combination is made versus different environmental conditions and system parameters.        

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:liu:diva-128058 (URN)10.1117/1.OE.53.1.013109 (DOI)
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2017-11-30
Grönwall, C., Törnqvist, D., Larsson, H. & Engström, P. (2013). Concurrent object recognition and localization for first responder applications. In: : . Paper presented at TAMSEC.
Open this publication in new window or tab >>Concurrent object recognition and localization for first responder applications
2013 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Signal Processing
Identifiers
urn:nbn:se:liu:diva-128050 (URN)
Conference
TAMSEC
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2016-08-31
Sjöqvist, L., Henriksson, M., Grönwall, C., Jonsson, P., Olofsson, T. & Steinvall, O. (2013). High resolution TCSPC range-profiling and tomography in remote sensing applications. In: : . Paper presented at TAMSEC.
Open this publication in new window or tab >>High resolution TCSPC range-profiling and tomography in remote sensing applications
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2013 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Signal Processing
Identifiers
urn:nbn:se:liu:diva-128048 (URN)
Conference
TAMSEC
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2016-08-31
Steinvall, O., Chevalier, T. & Grönwall, C. (2013). Simulating the performance of laser imaging and range profiling of small surface vessels. In: Proceedings of SPIE: . Paper presented at Laser Radar Technology and Applications XVIII. , 8731
Open this publication in new window or tab >>Simulating the performance of laser imaging and range profiling of small surface vessels
2013 (English)In: Proceedings of SPIE, 2013, Vol. 8731Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The detection and classification of small surface targets at long ranges is a growing need for naval security. This paper will discuss simulations of a laser radar at 1.5 μm aimed for search, detect and recognition of small maritime targets.

The data for the laser radar system will be based on present and realistic future technology. The simulations will incorporate typical target movements at different sea states, vessel courses, effects of the atmosphere and for given laser system parameters also include different beam jitter. The laser pulse energy, repetition rate as well as the receiver and detector parameters have not been changed during the simulations.

A discussion of the classification potential based on information in 1D, 2D and 3D data separately and in combination will be made vs. different environmental conditions and system parameters. System issues when combining the laser radar with IR/TV and a range-Doppler radar will also be commented.

Keywords
Range-gated imaging, burst illumination, 3 D, ladar, small boats, laser signatures
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:liu:diva-128046 (URN)10.1117/12.2015109 (DOI)
Conference
Laser Radar Technology and Applications XVIII
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2016-08-31
Tolt, G., Chevalier, T., Engström, P. & Grönwall, C. (2012). Applications of 3D occupancy grids in a target analysis context. In: Proceedings of SPIE: . Paper presented at Laser Radar Technology and Applications XVII. , 8379
Open this publication in new window or tab >>Applications of 3D occupancy grids in a target analysis context
2012 (English)In: Proceedings of SPIE, 2012, Vol. 8379Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The new generation of laser-based imaging sensors enables collection of range images at video rate at the expense of somewhat low spatial and range resolution. Combining several successive range images, instead of having to analyze each image separately, is a way to improve the performance of feature extraction and target classification. In the robotics community, occupancy grids are commonly used as a framework for combining sensor readings into a representation that indicates passable (free) and non-passable (occupied) parts of the environment. In this paper we demonstrate how 3D occupancy grids can be used for outlier removal, registration quality assessment and measuring the degree of unexplored space around a target, which may improve target detection and classification. Examples using data from amaritime scene, acquired with a 3D FLASH sensor, are shown.

Keywords
Lidar, 3D registration, 3D occupancy grid.
National Category
Signal Processing
Identifiers
urn:nbn:se:liu:diva-128042 (URN)10.1117/12.919103 (DOI)
Conference
Laser Radar Technology and Applications XVII
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2016-08-31
Henriksson, M., Olofsson, T., Grönwall, C., Brännlund, C. & Sjöqvist, L. (2012). Optical reflectance tomography using TCSPC laser radar. In: Proc. SPIE: . Paper presented at Electro-Optical Remote Sensing, Photonic Technologies, and Applications VI. , 8542
Open this publication in new window or tab >>Optical reflectance tomography using TCSPC laser radar
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2012 (English)In: Proc. SPIE, 2012, Vol. 8542Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Tomographic signal processing is used to transform multiple one-dimensional range profiles of a target from different angles to a two-dimensional image of the object. The range profiles are measured by a time-correlated single-photon counting (TCSPC) laser radar system with approximately 50 ps range resolution and a field of view that is wide compared to the measured objects. Measurements were performed in a lab environment with the targets mounted on a rotation stage. We show successful reconstruction of 2D-projections along the rotation axis of a boat model and removal of artefacts using a mask based on the convex hull. The independence of spatial resolution and the high sensitivity at a first glance makes this an interesting technology for very long range identification of passing objects such as high altitude UAVs and orbiting satellites but also the opposite problem of ship identification from high altitude platforms. To obtain an image with useful information measurements from a large angular sector around the object is needed, which is hard to obtain in practice. Examples of reconstructions using 90 and 150° sectors are given. In addition, the projection of the final image is along the rotation axis for the measurement and if this is not aligned with a major axis of the target the image information is limited. There are also practical problems to solve, for example that the distance from the sensor to the rotation centre needs to be known with an accuracy corresponding to the measurement resolution. The conclusion is that that laser radar tomography is useful only when the sensor is fixed and the target rotates around its own axis. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Keywords
Laser radar; Reflective tomography; Range profiling; TCSPC; Single photon counting
National Category
Signal Processing Computer Vision and Robotics (Autonomous Systems)
Identifiers
urn:nbn:se:liu:diva-128044 (URN)10.1117/12.974493 (DOI)
Conference
Electro-Optical Remote Sensing, Photonic Technologies, and Applications VI
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2018-01-10
Grönwall, C., Rydell, J. & Jouni, R. (2011). Accurate indoor positioning of first responders. In: : . Paper presented at TAMSEC.
Open this publication in new window or tab >>Accurate indoor positioning of first responders
2011 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Signal Processing
Identifiers
urn:nbn:se:liu:diva-128011 (URN)
Conference
TAMSEC
Available from: 2016-05-16 Created: 2016-05-16 Last updated: 2016-08-31
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4434-8055

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