Instruments for Optical and Radio I

Dr L. Fletcher
10 lectures, starting 1st October 2004

This ten-lecture H-level lecture course introduces the basic ideas necessary to understand the design and use of radio telescopes in astrophysics. We will cover the basic measurements of ratio astronomy, the design of single antennas and multiple antenna systems, and the combination of information from multiple antennas in interferometric arrays.

Books
There is no single recommended textbook for this course, but useful material can be found in:
An Introduction to Radio Astronomy, 2nd Edition, Burke and Graham-Smith (CUP)
Radio Astronomy, 2nd Edition, Kraus, (CQ Books).

Websites
The following is an excellent web resource for radio astronomy, and provides in depth material and background for many aspects of the course:
Prof. Dale Gary's radio astronomy lecture course, New Jersey Institute of Technology.

Course Outline

Introduction: Historical overview of radio astronomy; basic concepts; sources of radio emission; radio spectra from thermal, bremsstrahlung and synchrotron sources.

A simple antenna: The antenna beam and power pattern; the antenna temperature, system temperature and their relationship to brightness temperature; detector sensitivity and the equation of radio astronomy; the 'total power' radio telescope.

Antenna arrays: The array power pattern and the aperture distribution, convolution with the signal; theory of interferometry, the u-v plane, imaging an extended source, source visibilities and the van Cittert-Zernicke theorem

Implementation of interferometry: Signal correlation, Earth-rotation synthesis, fringe rate and path compensation; 2-D aperture synthesis, VLBI and its requirements, image reconstruction.

Course materials

Lectures and Websites

Below you will find pdf versions of the slides I have shown during the lectures. You will receive the handouts during the lectures themselves; however in the versions posted on the web I have implemented corrections which have been brought to my attention (and marked with a small tick) . You should therefore look at these to correct errors in the handouts.

Lecture 1 - History and Introduction

Notes (pdf)
Handouts:[Course outline (.doc) ]
Websites: [History of Radio Astronomy (from NRAO) , Blackbody radiation , Brightness Temperature (from Wolfram)]

Lecture 2 - Radiation Emission Mechanisms

Notes (pdf)
Websites: [Cyclotron formula - make sure you look at the SI (MKS) version! ]

Lecture 3 - Radio Signals and Antennas

Notes (pdf)
Websites: [Power Pattern, [Nice article on power patterns ]

Lecture 4 - Antenna Temperature, Radio Power Measurement (intro)

Notes (pdf)
Websites: [Antenna Temperature, [Notes from Paul van der Werf, Leiden University ]

Lecture 5 - System Temperature, Equation of Radio Astronomy

Notes (pdf)

Lecture 6 - Antenna Distributions and Power Pattern

Notes (pdf)
Websites: [Applet lets you generate power pattern for different linear arrays]