Radio astronomy 1

A.Y. 2020/2021
Overall hours
Learning objectives
The objective of this course is to provide the key knowledge of instruments and methods used in astronomical observations in a wide range of frequencies, from radio to sub-millimetric waves. The course is structured around three main topics: receivers, antennas and telescopes, interferometry
Expected learning outcomes
At the end of the course the student will:
· Understand the basic principles and theories of the propagation of electro magnetic waves through radio and microwave transmission lines and receivers
· Know the main types of radio astronomical antennas, with particular reference to corrugated feed horn antennas and reflector antennas
· Understand the principles and characteristics of coherent total power receivers, differential receivers, coherent pseudo-correlation polarimeters, incoherent receivers (bolometers, TES, Kinetic Inductance detectors)
· Understand the noise properties of the main types of receivers. He will be able to calculate the noise temperature of a simple radiometer
· Understand the theory of the two-antenna interferometer and the basis of the aperture-synthesis interferometry
Course syllabus and organization

Single session

Lesson period
First semester
Lessons can be followed live using the Zoom platform and will also be recorded so that students can follow them asynchronously. Lessons recordings will be available to students on the Ariel site of the course.

According to the COVID-19 situation students might be able to follow some of the lessons with physical presence. The procedures to participate to such lessons (students will have to book with a dedicated app) will be published in advance on the Ariel site of the course. The same will be for any other update following the evolution of the COVID-19 pandemic.
Course syllabus
The course is organized around and introductory part and three main topics. In the introduction we recall the basic concepts of electromagnetism and signal/noise characteristic and analysis

The three main topics are:

· Receivers. In this part we deal with the characteristics, advantages and limitations of coherent and incoherent receivers. We will also discuss frontier technologies like, for example, ultra low-noise detectors like Kinetic Inductance Detectors (KIDs)

· Antennas and telescopes. In this part we will discuss the basic concepts that allow us to study the interaction of the electromagnetic radiation and antennas. Then we focus on the main types of antennas used in radio astronomy presenting some of the latest and most relevant examples

· Elements of interferometry. In this part we will focus on interferometry, a technique that allowed us, in the latest years, to obtain high-resolution images of celestial sources in the radio and microwave part of the spectrum. We will start from the basic two-antenna interferometer and then we will approach more complex systems characterized by several antennas that allow us to obtain real sky maps. We will also describe the main ongoing and future interferometric projects

The course is preparatory for the following courses: Radio Astronomy 2, Laboratory of Space Instrumentation
Prerequisites for admission
No particular prerequisites
Teaching methods
The course is based on lectures
Teaching Resources
Slides available on Ariel

An introduction to Radio Astronomy, B. Burke and F. Graham-Smith, Cambridge Univ. Press
Assessment methods and Criteria
There is an oral exam split in two parts. In the first part the student presents a topic at his/her choice among those treated during the course, in the second the teacher asks questions regarding the remaining parts
FIS/05 - ASTRONOMY AND ASTROPHYSICS - University credits: 6
Lessons: 42 hours
Professor: Mennella Aniello
Educational website(s)