Comparative evaluation of ISAR processing algorithms

Tufan, Alper
In this thesis, Inverse Synthtetic Aperture Radar image reconstruction techniques, named as Range Doppler, Back Projection, Polar Formatting, Multiple Signal Classification (MUSIC) and Time Frequency techniques are analysed and compared using simulations. Time Frequency techniques investigated in this thesis are Short Time Fourier Transform, Wigner-Ville Distribution, Smoothed Wigner-Ville Distribution and Choi-Williams Distribution. First, some fundamental concepts of ISAR, such as resolution, range profile, time dependent Doppler frequency are given. A data simulator is designed and implemented for the purpose of providing configurable input to ISAR signal processing algorithms for a given ISAR target geometry. Estimation of target rotational velocity is explained with the help of three methods, namely Grid Search, WVD Slope and Radon Wigner-Hough Transform. Then, theoretical background of image formation algorithms is discussed. MATLAB simulations for each algorithm are implemented with several configurations in order to visualize and analyse the results. Finally, processing algorithms are compared to discuss the advantages and disadvantages.


Comparative evaluation of SAR image formation algorithms
Şahin, Halil İbrahim; Dural Ünver, Mevlüde Gülbin; Koç, Seyit Sencer; Department of Electrical and Electronics Engineering (2010)
In the scope of this thesis, simulation-based analyses and comparative evaluation of Synthetic Aperture Radar (SAR) image formation techniques, namely Time Domain Correlation, Range Stacking, Range Doppler and Chirp Scaling algorithms, are presented. For this purpose, first, the fundamental concepts of SAR such as SAR geometry, resolution and signal properties are explained. A broadside SAR simulator that provides artificial raw data as an input to the algorithms is designed and implemented. Then, the mathe...
Radar cross section analysis by shooting and bouncing rays method
Çakır, Mustafa Kağan; Tokdemir, Turgut; Department of Engineering Sciences (2015)
In this study, a MATLAB code incorporating `Shooting and Bouncing Rays (SBR) Method` is developed for calculating Radar Cross Section (RCS) of complex shapes. The code can calculate ray paths, magnetic current sheets, incident and scattered electric fields and RCS in horizontal, vertical and cross polarizations. While reflection effects are calculated by SBR algorithm, diffraction effects due to edges and corners are handled by `Equivalent Edge Currents (EEC’s)`. Wave frequency, aspect angle and number of r...
Prospects of FMCW-based frequency diverse array radar
Cetiner, Ramazan; Cetintepe, Cagri; Demir, Şimşek; Hizal, Altunkan (2019-11-01)
The linear frequency modulated (LFM) frequency modulated continuous wave (FMCW)-based frequency diverse array (FDA) radar concept is investigated in detail. The radar operates as a linear pulsed FMCW/FDA in the transmission (TX) mode while it operates as a pulsed FMCW/phased array (PA) in the receiving mode. The issues such as low signal-to-noise ratio (SNR) of FDA, the time-angle scanning and time-range ambiguities are studied. It is shown that the local instantaneous frequency bandwidth is much smaller th...
Differential Sensitivity Analysis for the Orthorectification of Small Satellite Images
Bettemir, Oe. H. (2009-06-13)
By using differential sensitivity analysis, horizontal and vertical accuracy of orthorectification of monoscopic images taken by small satellites without using Ground Control Points (GCP) is predicted. The analysis is performed by differentiating the colinearity equation of orthorectification procedure with respect to the satellite's interior and exterior parameters, and elevation obtained from digital elevation model (DEM). Square of the differential equations with respect to parameters are multiplied with...
Image Chain Simulation for Earth Observation Satellites
Alici, Kamil B.; Öktem, Sevinç Figen; Karci, Ozgur; Yilmaz, A. Serdar; Selimoglu, Ozgur (Institute of Electrical and Electronics Engineers (IEEE), 2019-10-01)
We present a general-purpose end-to-end image chain simulation (ICS) that enables to assess the image quality of a satellite imager for Earth observations. The image chain consists of four main components: radiometry, atmosphere, optics, and detector. In particular, ICS first computes the input radiance from the reflectance values of a high-resolution input, and then calculates the image radiance by using the optical transfer function (OTF) of the overall system. This OTF contains all the distortion effects...
Citation Formats
A. Tufan, “Comparative evaluation of ISAR processing algorithms,” M.S. - Master of Science, Middle East Technical University, 2012.