lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A study of some FMCW radar algorithms for target location at low frequencies
Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.ORCID iD: 0000-0003-3217-6361
Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.ORCID iD: 0000-0002-5522-0110
2016 (English)In: Radio Science, ISSN 0048-6604, E-ISSN 1944-799X, Vol. 51, no 10, p. 1676-1685Article in journal (Refereed) Published
Abstract [en]

FMCW (Frequency Modulated Continuous Wave) radar is a simple and inexpensive technique for target location. The resolution is given by the available bandwidth and the directivity of the antenna. Resolution is not a problem at high frequencies, while at low frequencies, and especially for mobile platforms, the required size of the antenna becomes impractical. In order to obtain the bearing of the targets, without relying on directivity, one may use a simple two-dimensional trilateration method that involves several platforms. The problem of ghost targets has been studied for both monostatic and multistatic radar. When there is a confluence of echoes, the relation between accuracy and bandwidth is of particular interest. 

Place, publisher, year, edition, pages
2016. Vol. 51, no 10, p. 1676-1685
Keywords [en]
FMCW radar; low frequency; target location; trilateration
National Category
Signal Processing
Research subject
Physics, Waves and Signals
Identifiers
URN: urn:nbn:se:lnu:diva-49696DOI: 10.1002/2016RS005974ISI: 000388949900006Scopus ID: 2-s2.0-84995532108OAI: oai:DiVA.org:lnu-49696DiVA, id: diva2:902364
Available from: 2016-02-11 Created: 2016-02-11 Last updated: 2018-12-11Bibliographically approved
In thesis
1. High frequency scattering and spectral methods
Open this publication in new window or tab >>High frequency scattering and spectral methods
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis consists of five parts. The first part is an introduction with references to some recent work on 2D electromagnetic scattering problems at high frequencies. It also presents the basic integral equation types for impenetrable objects and the standard elements of the method of moments. An overview of frequency modulated radar at low frequencies is followed by summaries of the papers.

Paper I presents an accurate implementation of the method of moments for a perfectly conducting cylinder. A scaling for the rapid variation of the solution improves accuracy. At high frequencies, the method of moments leads to a large dense system of equations. Sparsity in this system is obtained by the modification of the path in the integral equation. The modified path reduces the accuracy in the deep shadow.

In paper II, a hybrid method is used to handle the standing waves that are prominent in the shadow for the cylindrical TE case. The shadow region is treated separately, in a hybrid scheme based on a priori knowledge about the solution. An accurate method to combine solutions in this hybrid scheme is presented.

In paper III, the surface current in the shadow zone of a convex or a concave scatterer is approximated by extracting the dominant waves. An accurate technique based on the symmetric discrete Fourier transform is used to extract the complex wavenumbers and amplitudes for those waves. The dominant waves constitute a concise form of scaling that is used to improve the performance of the method of moments. The effect of surface curvature on the dominant waves has been investigated in this work.

In paper IV, frequency modulated continuous wave radar (FMCW) at low frequency is studied as a way to locate targets that are normally not detected by conventional radar. Three separate platforms with isotropic antennas are used for this purpose. The trilateration method is a way to locate the targets accurately by means of spectral techniques.

The problem of ghost targets has been studied for monostatic and multistatic radar. In the case of confluent echoes in the spectra, potentially missing echoes are reinserted in order to locate all targets. The Capon method is used to obtain high resolution spectra and thus reduce the confluence problem. The need for bandwidth is also reduced.

Place, publisher, year, edition, pages
Växjö: Linnaeus University Dissertations, 2016. p. 108
Series
Linnaeus University Dissertations ; 265/2016
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-57871 (URN)978-91-88357-40-3 (ISBN)
Public defence
2016-12-07, C2102, Hus C, Växjö, 14:00 (English)
Opponent
Supervisors
Available from: 2016-11-09 Created: 2016-11-09 Last updated: 2018-12-11Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Sandström, Sven-ErikAkeab, Imad

Search in DiVA

By author/editor
Sandström, Sven-ErikAkeab, Imad
By organisation
Department of Physics and Electrical Engineering
In the same journal
Radio Science
Signal Processing

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 299 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf