Dept. of

Information Engineering
 

Center of Excellence CETEMPS

University of L'Aquila

Institute of Atmospheric Science  and Climate (ISAC)

PROGRAM AND OBJECTIVES

The 3 credits (CFU) of Electromagnetics fundamentals are organized into 5 sessions that include theoretical teaching and practical exercises. The module will cover the following aspects:

A1. ELECTROMAGNETICS FUNDAMENTALS

Introduction to electromagnetics: Properties of the differential operators. Solenoidal and irrotational fields. Fundamental Theorems of Vector Analysis. Maxwell’s Equations and Continuity Conditions. Properties: Duality Principle and Impressed Sources. Constitutive Relations.

A2. THEOREMS AND WAVE EQUATION

Maxwell’s Equations: Complex notation and equations. Constitutive relations in frequency. Dispersive media. Poynting’s theorem. uniqueness theorem. Electromagnetic wave equation: Helmholtz equation. Electromagnetic potentials.

A3. ELECTROMAGNETIC PLANE WAVES

Plane waves: Wave functions. Plane wave solutions. General properties of plane waves. Spectrum of plane waves. Non-monochromatic plane waves. Reflection and transmission of plane waves: Normal incidence. Oblique Incidence. Snell’s law. Fresnel’s coefficients. Total reflection. Leontovich’s condition.

A4. ELECTROMAGNETIC MATERIALS

Permittivity in the spectral domain: Non-polar non-conducting materials and the Lorenz model. Polar materials and the Debye model. Conducting materials. Permittivity vs. conductivity. Permittivity of terrestrial materials: The atmosphere. Water and ice. Vegetal tissues. Soil. The ionosphere.

A5. ELECTROMAGNETIC RADIATION AND SCATTERING

Electromagnetic radiation: Impulse response of free space: The scalar Green’s function. Doppler effect. Wave Interference. Field of Point Source. Radiated field: Field of finite-dimension sources. The far field. Radiation parameters. Reciprocity and equivalence. Scatter modeling: scattering source. scattered field. scattering matrix. Müller matrix. Scattered power. Transverse sections. The backscattering coefficient. Antennas: Radiating Antennas: Directivity and Reaction. Receiving antennas: Aperture efficiency and effective Area. Directional properties of apertures.

The 3 credit (CFU) radar meteorology module is organized into 5 sessions that include theoretical teaching and practical exercise. An external visit to the ISAC-CNR radar hardware in Rome could be planned according to time availability and permissions. The module will cover the following aspects:

B1. RADAR METEOROLOGY INTRODUCTION

Introduction: Radar principle, advantage and concepts of microwave remote sensing, summary of microwave sensor typology History of radar. Examples: Weather radars at the ground, on air and space platforms, the electromagnetic spectrum, frequency selection for weather radars.

B2. RADAR MEASUREMENT PRINCIPLES

Geometrical characteristics of radar observation: Range resolution, radar antenna features, cross resolution, geometry of acquisition. Radar ray paths: Ray propagation in the vacuum and in stratified atmosphere, anomalous propagation. Radar equation: Particle’s scattering cross section, radar equation for single and multiple target targets, particle size distribution, Reflectivity and equivalent reflectivity factor, validity of Rayleigh approximation, minimum detectable reflectivity.

B3. RADAR SYSTEMS

Doppler radars: Radial velocity, Doppler spectrum, moments of Doppler spectrum, Velocity Ambiguity, Dilemma Doppler, radar signal processing (autocorrelation function), coherency time of the received signal. B6. Dual polarization radars. Polarimetry, Scattering Matrix, Radar system configurations, differential reflectivity, linear depolarization ratio, propagation differential phase, correlation coefficient.

B4 GROUND-BASED RADAR APPLICATIONS

Attenuation effects of weather radar signal: Path attenuation, Attenuation compensation algorithms. Radar calibration: Calibration techniques, ground clutter, radio frequency interference. Radar applications: Rain Estimation, Hydrometer Classification, Zdr columns, Radar and lightings.

B5. SPACE-BASED RADAR APPLICATIONS.

Estimates from microwave radar and radiometer satellite sensors: Algorithm for precipitation estimation from satellite. Application: use of products from GPM and Eumetsat missions.

EXAM PROCEDURES

Credits (Crediti formativi universitari, CFU). The credits are 6 corresponding to 60 hours of lectures/excercises.

Exam. The examination foresees 2 oral questions for each module. The grade is expressed in x/30 (with possible laude).

Optional work. A possible optional work on a topic, to be agreed with the teachers, may allow to skip 50% of the oral examination. The work must be presented by a wirtten report of no more than 20 pages.

DIDACTIC REFERENCES

Main references:

Orfanidis S.J., Electromagnetic waves and antennas, Freely available here (web site), 2008-16.

Frezza F., A primer on Electromagnetic Fields, Springer, 2015

Solimini D., Understanding Earth Observation, Springer, 2016

Rauber R.M. and S.L. Nesbitt, Radar Meteorology: A First Course, ISBN: 978-1-118-43262-4, May 2018, Wiley-Blackwell, 488 pages

Bringi V. N. and V. Chandrasekar, Polarimetric Doppler Weather Radar: principles and applications, Cambridge University Press, 2001

Doviak  R.J. and D.S. Zrnic, Doppler radar and weather observations, 2nd ed., Academic Press, 1993

Kidder and Von der Haar, Satellite meteorology, Academic Press, 1996

Sauvageot H., Radar meteorology, Artech House, Boston (MA), 1992

Stull R.B., Meteorology for scientists and engineers, 2nd ed., Brooks/Cole, 2000

INTERNSHIPS AND FINAL MASTER THESIS TOPICS

Interships.The available opportunities, equal to 3 credits (75 hours), can be asked to the teachers.

Thesis topics.The list can be asked to the teachers.

Duration. The final Master Thesis is equal to 27 credits which correspond to about 5 months of student work.