Insegnamento mutuato da: B010720 - SISTEMI RADAR Corso di Laurea Magistrale in INGEGNERIA DELLE TELECOMUNICAZIONI Curricula SISTEMI DI TELECOMUNICAZIONE
The main types of radar systems and signals are presented, analyzed and compared. With reference to the different radar applications, the different radar functions are described and analyzed, together with the main processing methods of data, signals and disturbances.
M. A. Richards: "Fundamentals of radar signal processing", Second edition, Mc Graw Hill, 2014
B.R. Mahafza: "Radar Systems analysis and design using MATLAB" 3rd edition, CRC press. 2013
G. Galati F. Mazzenga M. Naldi "Elementi di sistemi radar" Aracne Editrice,1996
N. Levanon, E. Mozeson: "Radar signals" Wiley, 2004
J.V. Di Franco, W.L. Rubin "Radar detection", Prentice Hall/Scitech
M. I. Skolnik: "Introduction to radar systems" Mc Graw Hill
R.E. Doviak, D Zrnic " Doppler radar and Weather observations" Academic Press, 1993
C. Elachi "Spaceborne radar remote sensing: applications and techniques" IEEE press, 1988
R. Meneghini, T. Kozu "Spaceborne Weather Radar, Artech House, 1990
1) Knowledge of the basics of the statistical detection of radar targets
2) Knowledge of the main different types of radar systems, of the signals employed and of their applications
3) Knogledge of the different types of disturbances affecting radar signals
4) Knowledge of the most important techniques of data and signals data processing
5) Ability to comparatively analyse benefits and drawbacks of the different radar system and signaling solutions
Random variables and stochastic processes, signal theory, digital signal processing, antennas
Lessons and class exercises
Type of Assessment
During the oral exam are assessed:
- through theoretical questions, the knowledge of the main different types of radar systems and signals, of data and signal processing and of statistical detection of radar targets, of the methods for suppressing or attenuating signal disturbances
- Through exercises, the ability to comparatively analyse benefits and drawbacks of the different radar system and signaling solutions
Functions of a radar system. Different types of radar systems and their applications. Types of radar signals. Continuous Wave (CW) radars. Continuous Wave Frequency Modulated (CW-FM) radars. Pulse radars . Resolution and ambiguity in range and Doppler. The Radar Cross Section and the radar equation. Radar coverage. Volume clutter and surface clutter. Radar coverage in clutter. Jamming. Radar coverage in Jamming. Matched filter and Doppler mismatch. Doppler filters bank. Digital signal processing of radar signals.
Radar primary function. Mathematical theory of statistical detection. Bayes' criterion and examples. Minimum error probability criterion. Neyman-Pearson criterion. Echo decorrelation time. Detection of fully known target and optimum receiver. Detection of non fluctuating target and optimum receiver. Detection of fluctuating target and optimum receiver. Detection based on a train of pulses: coherent train with known phase, coherent train with random phase. Optimum receiver for coherent trains. Detection of non fluctuating target based on a incoherent train of pulses. Optimum receivers for incoherent trains and non fluctuating targets. Integration loss. Detection of fluctuating target through an incoherent train. Swerling models. Internal and external noise and noise system temperature. Correction factors in the radar equation. Coherent detection of known target based on N pulses and non Gaussian disturbance. Detection of known target based on the maximization of the SNR. CFAR techniques.
Systems for clutter reduction:
MTI systems. Staggered PRF techniques. MTD systems.
Analysis of radar signals:
Pulse compression signals. Chirp pulses. Binary phase coded pulses. Optimum delay and Doppler estimators in the case of AWGN disturbance and estimate accuracy. The ambiguity function and its properties. Ambiguity function of rectangular non modulated pulse, chirp pulse and train of pulses.
Weather radar systems:
Introduction to radar meteorology. Rainfall models, Drop Size Distribution, rainfall intensity. Interactions among e.m. waves and precipitation. Reflectivity factor and expected power backscattered by a precipitation volume. Methods for classifying and estimating precipitation by radar: monoparameter e multiparameter methods. Reflectivity method. Attenuation method. Dual polarization (differential reflectivity) method. Doppler weather radar.
Synthetic Aperture Radars (SAR):
The SAR problem: ground range resolution, azimuth resolution (Doppler techniques), synthetic array approach. Azimuth resolution for unfocused and focused SAR. Direct SAR approach: isorange and isodoppler curves. Doppler and range ambiguity and their implications on the PRF. SAR signal processing. Notes on Interferometric SAR.