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Publications (10 of 102) Show all publications
Vu, V. T., Pettersson, M., Sjögren, T. & Gustavsson, A. (2018). A hybrid GMTI method for reliable detection results in SAR images. In: Proceedings - 2018 2nd International Conference on Recent Advances in Signal Processing, Telecommunications and Computing, SIGTELCOM 2018: . Paper presented at 2nd International Conference on Recent Advances in Signal Processing, Telecommunications and Computing, SIGTELCOM, Ho Chi Minh City (pp. 73-78). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>A hybrid GMTI method for reliable detection results in SAR images
2018 (English)In: Proceedings - 2018 2nd International Conference on Recent Advances in Signal Processing, Telecommunications and Computing, SIGTELCOM 2018, Institute of Electrical and Electronics Engineers Inc. , 2018, p. 73-78Conference paper, Published paper (Refereed)
Abstract [en]

Stand-alone synthetic aperture radar (SAR) ground moving target indication (GMTI) methods have both advantages and disadvantages. This paper introduces a hybrid SAR GMTI method that is based on two well-known methods: space time adaptive processing (STAP) and moving target detection by focusing (MTDF). The input of the proposed hybrid method is two time separated complex radar images. The output is detected ground moving targets, the target normalized relative speeds (NRS), and focused images of the detected targets. In the paper, we provide the mathematical background behind the hybrid SAR GMTI method in details. We also provide some experimental results for validating the proposed method. The data for the experiments was acquired in early 2015 by TanDEM-X and TerraSAR-X operating in monostatic pursuit mode. The ground scene where the measurements were conducted is around Mantorp, west of Linköping, Sweden. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Radar signal processing, Space time adaptive processing, Synthetic aperture radar, Ground moving target indication, Ground moving targets, Hybrid method, Monostatic, Moving target detection, Reliable detection, Stand -alone, TerraSAR-X, Radar imaging
National Category
Signal Processing Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16538 (URN)10.1109/SIGTELCOM.2018.8325809 (DOI)2-s2.0-85047862168 (Scopus ID)9781538629765 (ISBN)
Conference
2nd International Conference on Recent Advances in Signal Processing, Telecommunications and Computing, SIGTELCOM, Ho Chi Minh City
Available from: 2018-06-18 Created: 2018-06-18 Last updated: 2018-06-18Bibliographically approved
Rameez, M., Dahl, M. & Pettersson, M. (2018). Adaptive digital beamforming for interference suppression in automotive FMCW radars. In: 2018 IEEE Radar Conference, (RadarConf 2018): . Paper presented at 2018 IEEE Radar Conference,Oklahoma City (pp. 252-256). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Adaptive digital beamforming for interference suppression in automotive FMCW radars
2018 (English)In: 2018 IEEE Radar Conference, (RadarConf 2018), Institute of Electrical and Electronics Engineers Inc. , 2018, p. 252-256Conference paper, Published paper (Refereed)
Abstract [en]

This paper addresses the problem of mutual interference between automotive radars. This problem is getting more attention with an increase in the number of radar systems used in traffic. An adaptive digital beamforming technique is presented here which suppresses the interference without the exact knowledge of the interfering signal's Direction of Arrival (DoA). The proposed technique is robust and does not rely on any calibration for the interference cancellation. The adaptive interference suppression method is evaluated using a simulated scenario. Up to about 20-23 dB improvement in the target Signal to Interference and Noise Ratio (SINR) is measured in the simulation and a better detection performance is achieved using the proposed interference suppression technique. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Series
IEEE Radar Conference
Keywords
Beamforming, Frequency modulation, Radar systems, Signal to noise ratio, Adaptive digital beamforming, Adaptive interference suppression, Automotive radar, Detection performance, Interference cancellation, Interfering signals, Mutual interference, Target signals, Radar interference
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16910 (URN)10.1109/RADAR.2018.8378566 (DOI)000442172700046 ()2-s2.0-85049977586 (Scopus ID)978-1-5386-4167-5 (ISBN)
Conference
2018 IEEE Radar Conference,Oklahoma City
Available from: 2018-08-20 Created: 2018-08-20 Last updated: 2018-09-20Bibliographically approved
Sievert, T., Rasch, J., Carlström, A. & Pettersson, M. (2018). Analysis of reflections in GNSS radio occultation measurements using the phase matching amplitude. Atmospheric Measurement Techniques, 11, 569-580
Open this publication in new window or tab >>Analysis of reflections in GNSS radio occultation measurements using the phase matching amplitude
2018 (English)In: Atmospheric Measurement Techniques, ISSN 1867-1381, E-ISSN 1867-8548, Vol. 11, p. 569-580Article in journal (Refereed) Published
Abstract [en]

It is well-known that in the presence of super-refractive layers in the lower-tropospheric inversion of GNSSradio occultation (RO) measurements using the Abel trans-form yields biased refractivity profiles. As such it is problem-atic to reconstruct the true refractivity from the RO signal.Additional information about this lower region of the atmo-sphere might be embedded in reflected parts of the signal. Toretrieve the bending angle, the phase matching operator canbe used. This operator produces a complex function of theimpact parameter, and from its phase we can calculate thebending angle. Instead of looking at the phase, in this paperwe focus on the function’s amplitude. The results in this pa-per show that the signatures of surface reflections in GNSSRO measurements can be significantly enhanced when usingthe phase matching method by processing only an appropri-ately selected segment of the received signal. This signatureenhancement is demonstrated by simulations and confirmedwith 10 hand-picked MetOp-A occultations with reflectedcomponents. To validate that these events show signs of re-flections, radio holographic images are generated. Our resultssuggest that the phase matching amplitude carries informa-tion that can improve the interpretation of radio occultationmeasurements in the lower troposphere.

National Category
Remote Sensing Meteorology and Atmospheric Sciences
Identifiers
urn:nbn:se:bth-15843 (URN)10.5194/amt-11-569-2018 (DOI)
Funder
Knowledge Foundation, 20140192Swedish National Space Board, 241/15
Note

open access

Available from: 2018-01-31 Created: 2018-01-31 Last updated: 2018-02-22Bibliographically approved
Vu, V. T., Gomes, N. R., Pettersson, M., Dämmert, P. & Hellsten, H. (2018). Bivariate Gamma Distribution for Wavelength-Resolution SAR Change Detection. IEEE Transactions on Geoscience and Remote Sensing
Open this publication in new window or tab >>Bivariate Gamma Distribution for Wavelength-Resolution SAR Change Detection
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2018 (English)In: IEEE Transactions on Geoscience and Remote Sensing, ISSN 0196-2892, E-ISSN 1558-0644Article in journal (Refereed) Epub ahead of print
Abstract [en]

A gamma probability density function (pdf) is shown to be an alternative to model the distribution of the magnitudes of high-resolution, i.e., wavelength-resolution, synthetic aperture radar (SAR) images. As investigated in this paper, it is more appropriate and more realistic statistical in comparison with, e.g., Rayleigh. A bivariate gamma pdf is considered for developing a statistical hypothesis test for wavelength-resolution incoherent SAR change detection. The practical issues in implementation of statistical hypothesis test, such as assumptions on target magnitudes, estimations for scale and shape parameters, and implementation of modified Bessel function, are addressed. This paper also proposes a simple processing scheme for incoherent change detection to validate the proposed statistical hypothesis test. The proposal was experimented with 24 CARABAS data sets. With an average detection probability of 96%, the false alarm rate is only 0.47 per square kilometer. IEEE

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Bivariate gamma, CARABAS, change detection, synthetic aperture radar (SAR)., Probability density function, Probability distributions, Radar imaging, Statistical tests, Tracking radar, Bivariate, Bivariate gamma distribution, Probability density function (pdf), Scale and shape parameters, Statistical hypothesis test, Synthetic aperture radar (SAR) images, Synthetic aperture radar
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16936 (URN)10.1109/TGRS.2018.2856926 (DOI)2-s2.0-85051396922 (Scopus ID)
Available from: 2018-08-24 Created: 2018-08-24 Last updated: 2018-08-24Bibliographically approved
Sievert, T., Rasch, J., Carlström, A., Pettersson, M. & Vu, V. T. (2018). Comparing reflection signatures in radio occultation measurements using the full spectrum inversion and phase matching methods. In: PROCEEDINGS VOLUME 10786; Remote Sensing of Clouds and the Atmosphere XXIII: . Paper presented at SPIE Remote Sensing, Berlin. SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Comparing reflection signatures in radio occultation measurements using the full spectrum inversion and phase matching methods
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2018 (English)In: PROCEEDINGS VOLUME 10786; Remote Sensing of Clouds and the Atmosphere XXIII, SPIE - International Society for Optical Engineering, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Global Navigation Satellite System Radio Occultation (GNSS-RO) is an important technique used to sound the Earth's atmosphere and provide data products to numerical weather prediction (NWP) systems as well as toclimate research. It provides a high vertical resolution and SI-traceability that are both valuable complements toother Earth observation systems. In addition to direct components refracted in the atmosphere, many received RO signals contain reflected components thanks to the specular and relatively smooth characteristics of the ocean. These reflected components can interfere the retrieval of the direct part of the signal, and can also contain meteorological information of their own, e.g., information about the refractivity at the Earth's surface. While the conventional method to detect such reflections is by using radio-holographic methods, it has been shown that it is possible to see reflections using wave optics inversion, specically while inspecting the amplitude of the output of phase matching (PM). The primary objective of this paper is to analyze the appearance of these reflections in the amplitude output from another wave optics algorithm, namely the much faster full spectrum inversion (FSI). PM and FSI are closely related algorithms - they both use the method of stationary phase to derive the bending angle from a measured signal. We apply our own implementation of FSI to the same GNSS-RO measurements that PM was previously applied to and show that the amplitudes of the outputs again indicate reflection in the surface of the ocean. Our results show that the amplitudes output from the FSI and PM algorithms are practically identical and that the reflection signatures thus appear equally well.

Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2018
Keywords
radio occultation, wave optics, re ections, full spectrum inversion
National Category
Meteorology and Atmospheric Sciences Signal Processing
Identifiers
urn:nbn:se:bth-17132 (URN)10.1117/12.2325386 (DOI)
Conference
SPIE Remote Sensing, Berlin
Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2018-10-17Bibliographically approved
Vu, V. T. & Pettersson, M. (2018). Derivation of Bistatic SAR Resolution Equations Based on Backprojection. IEEE Geoscience and Remote Sensing Letters, 15(5), 694-698
Open this publication in new window or tab >>Derivation of Bistatic SAR Resolution Equations Based on Backprojection
2018 (English)In: IEEE Geoscience and Remote Sensing Letters, ISSN 1545-598X, E-ISSN 1558-0571, Vol. 15, no 5, p. 694-698Article in journal (Refereed) Published
Abstract [en]

This letter introduces ground-range and cross-range resolution equations for the side-looking bistatic synthetic aperture radar (SAR). The derivation is based on the backprojection integral and the method of stationary phase. The ground-range and cross-range resolution equations are provided in closed form, making them easy for calculation. They are, therefore, helpful for bistatic SAR system development. The derived ground-range and cross-range resolution equations are validated with the bistatic data simulated mainly using the parameters of the LORA system. IEEE

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Bistatic, resolution equation, stationary phase, synthetic aperture radar (SAR).
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16025 (URN)10.1109/LGRS.2018.2810314 (DOI)000430730200012 ()2-s2.0-85043458813 (Scopus ID)
Available from: 2018-03-26 Created: 2018-03-26 Last updated: 2018-05-11Bibliographically approved
Vu, V. T. & Pettersson, M. (2018). Range migration algorithm for bistatic SAR. In: IEEE Radar Conference, (RadarConf 2018): . Paper presented at 2018 IEEE Radar Conference, RadarConf., Oklahoma City (pp. 665-669). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Range migration algorithm for bistatic SAR
2018 (English)In: IEEE Radar Conference, (RadarConf 2018), Institute of Electrical and Electronics Engineers Inc. , 2018, p. 665-669Conference paper, Published paper (Refereed)
Abstract [en]

The paper introduces a Range Migration algorithm for bistatic SAR data processing. The algorithm is developed on the available function representing the two-dimension Fourier transform of the bistatic SAR data and relationship between radar signal frequency and wave-numbers for bistatic SAR or the ω - k relationship. The algorithm is tested with the simulations using different SAR geometries for validation. Some inherit limits of the developed Range Migration algorithm and the possible solutions are also discussed in the paper. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Data handling, Bistatic SAR, Radar signals, Range migration algorithms, Two-dimension, Wave numbers, Synthetic aperture radar
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16911 (URN)10.1109/RADAR.2018.8378638 (DOI)000442172700118 ()2-s2.0-85049929099 (Scopus ID)978-1-5386-4167-5 (ISBN)
Conference
2018 IEEE Radar Conference, RadarConf., Oklahoma City
Available from: 2018-08-20 Created: 2018-08-20 Last updated: 2018-09-13Bibliographically approved
Vu, V. T., Pettersson, M., Dämmert, P. & Hellsten, H. (2018). Two-Dimensional Data Conversion for One-Dimensional Adaptive Noise Canceler in Low Frequency SAR Change Detection. IEEE Transactions on Aerospace and Electronic Systems
Open this publication in new window or tab >>Two-Dimensional Data Conversion for One-Dimensional Adaptive Noise Canceler in Low Frequency SAR Change Detection
2018 (English)In: IEEE Transactions on Aerospace and Electronic Systems, ISSN 0018-9251, E-ISSN 1557-9603Article in journal (Refereed) Epub ahead of print
Abstract [en]

One-dimensional (1-D) adaptive noise canceler (ANC) has been used for false alarm reduction in low frequency SAR change detection. The paper presents possibilities to process two-dimensional (2-D) data by an 1-D ANC. Beside concatenating the rows of 2-D data in a matrix form to convert it to 1-D data in a vector form, two conversion approaches are considered: concatenating the columns of 2-D data and local concatenation, i.e., the conversion to 1-D is performed locally on each block of the 2-D data. A ground object can occupy more than one row and/or more than one column of 2-D data. In addition, the properties in cross-range and range of an image are not the same. Thus, different conversion approaches may lead to different performance of an 1-D ANC and hence different change detection results. Among the considered approaches, the local concatenating approach is shown to provide slightly better performance in terms of probability of detection and false alarm rate. IEEE

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Adaptive signal processing, ANC, Azimuth, change detection, Frequency conversion, Matrix converters, Noise measurement, SAR, statistics, Synthetic aperture radar, Wires, Chemical detection, Errors, Matrix algebra, Optical frequency conversion, Signal processing, Spurious signal noise, Wire, Adaptive noise cancelers, False alarm reductions, Noise measurements, Probability of detection, Two Dimensional (2 D), Data handling
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-17002 (URN)10.1109/TAES.2018.2866742 (DOI)2-s2.0-85052685958 (Scopus ID)
Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2018-09-13Bibliographically approved
Fabrin, A., Molin, R., Alves, D. I., Machado, R., Bayer, F. & Pettersson, M. (2017). A CFAR optimization for low frequency UWB SAR change detection algorithms. In: International Geoscience and Remote Sensing Symposium (IGARSS): . Paper presented at 37th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS, Fort Worth (pp. 1071-1074). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>A CFAR optimization for low frequency UWB SAR change detection algorithms
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2017 (English)In: International Geoscience and Remote Sensing Symposium (IGARSS), Institute of Electrical and Electronics Engineers Inc. , 2017, p. 1071-1074Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a study on the constant false alarm rate (CFAR) filter design for change detection algorithms (CDA). More specifically, we are interested in CFAR filters used in CDA for low frequency ultra-wideband (UWB) synthetic aperture radar (SAR) systems. The filter design performance was evaluated in terms of false alarm rate (FAR) and probability of detection (PD). For evaluation purposes, we considered a set of SAR images obtained with the CARABAS-II system. The results are compared with the ones presented in [1], where the same CDA was considered, except for the CFAR filter. The results show that relevant FAR performance improvements can be obtained by just modifying the CFAR filter parameters taking into account the image resolution and target characteristics. © 2017 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2017
Series
IEEE International Symposium on Geoscience and Remote Sensing IGARSS, ISSN 2153-6996
Keywords
CARABAS-II, CDA, CFAR, UWB SAR
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-15925 (URN)10.1109/IGARSS.2017.8127141 (DOI)000426954601057 ()2-s2.0-85041815057 (Scopus ID)9781509049516 (ISBN)
Conference
37th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS, Fort Worth
Available from: 2018-02-22 Created: 2018-02-22 Last updated: 2018-04-12Bibliographically approved
Barbosa, L., Rasch, J., Carlstrom, A., Pettersson, M. & Vu, V. T. (2017). A Simulation Study of the Effect of Ionospheric Vertical Gradients on the Neutral Bending Angle Error for GNSS Radio Occultation. In: Progress in Electromagnetics Research Symposium: . Paper presented at Progress in Electromagnetics Research Symposium - Fall (PIERS - FALL), Singapore (pp. 1540-1545). IEEE
Open this publication in new window or tab >>A Simulation Study of the Effect of Ionospheric Vertical Gradients on the Neutral Bending Angle Error for GNSS Radio Occultation
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2017 (English)In: Progress in Electromagnetics Research Symposium, IEEE , 2017, p. 1540-1545Conference paper, Published paper (Refereed)
Abstract [en]

Radio Occultation based on Global Navigation Satellite System signals (GNSS RO) is an increasingly important remote sensing technique. Its measurements are used to derive parameter of the Earth's atmosphere, e.g., pressure, temperature and humidity, with good accuracy. The systematic residual error present on the data processing is related to ionospheric conditions, such as the distribution of electrons and the resultant vertical gradient. This study investigates the relationship between these parameters and the residual ionospheric error (RIE) on the retrieved bending angle in the stratosphere. Chapman function combined to sinusoidal perturbations are used to model electron density profiles and compared to RO retrievals of the ionosphere to perform the investigation. The results confirmed that the major ionospheric influence on the retrieval error is related to the F-layer electron density peak, whereas small-scale vertical structures play a minor role.

Place, publisher, year, edition, pages
IEEE, 2017
Series
Progress in Electromagnetics Research Symposium, ISSN 1559-9450
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16124 (URN)000428518301099 ()978-1-5386-1211-8 (ISBN)
Conference
Progress in Electromagnetics Research Symposium - Fall (PIERS - FALL), Singapore
Available from: 2018-04-26 Created: 2018-04-26 Last updated: 2018-04-26Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6643-312x

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