Radio Astronomy: Tools, Applications & Impacts

Who:       U. Klein
When:     Winter term, Tuesday 4:15 p.m., Thursday 4:15 p.m.
Where:    AIfA, HS 0.03


This lecture is supposed to be attended by students studying main courses. Successful participation in the course on Theoretical Electrodynamics is a prerequisite; in addition, elementary courses in physics and mathematics are required. A successful participation in this class means 3 academic hours of lecturing per week, plus participation in the associated lab course. The latter usually takes place after the winter term (in a block).

Note that students in the Master of Astrophysics programme may perform this lab course as part of the advanced lab.

Any students who envisage a thesis in radio astronomy are strongly recommended to attend this lecture! In what follows a syllabus of the lecture is given, which is still subject to changes since it had to be 'glued together' from previously two courses.



1. Introduction
history
astrophysics and radio astronomy                              

2. Single-dish telescopes
Cassegrain and Gregory foci
geometries and ray tracing
antenna diagrams
antenna parameters

3. Fourier optics
Fourier transform
aperture – farfield relations
spatial frequencies and filtering
power pattern
convolution and sampling
resolving power

4. Influence of earth’s atmosphere
ionosphere, troposphere
plasma frequency
Faraday rotation
refraction, scintillation
absorption / emission                          
radiation transport

5
. Receivers
total-power and heterodyne systems
system temperature
antenna temperature, sensitivity
Dicke-, correlation receiver                                  
amplifiers
hot-cold calibration

6. Wave propagation in conductors
coaxial cables, waveguides
matching, losses
quasi optics                
                              
7.
Backend
continuum, IF-polarimeter                                  
spectroscopy
filter spectrometer
autocorrelator
acousto-optical spectrometer
pulsar backend

8.
mm and submm techniques

telescope parameters and observables
atmosphere, calibration, chopper wheel
error beam
SIS receivers
bolometers

9. Single-dish observing techniques
on-off, cross-Scan, Raster
continuous mapping, OTF, fast scanning                          
frequency-switching, wobbling technique

10.
Data analysis

sampling theorem
spectroscopy
multi-beam observations
image processing, data presentation

11. Interferometry basics
aperture - image plane
complex visibility
delay tracking
fringe rotation
sensitivity

12.
Imaging
Fourier inversion
cleaning techniques
self-calibration
zero-spacing correction

13.
VLBI

station requirements
processor
calibration and imaging
retarded baselines
geodesy

14. Spectroscopy
XF and FX correlation
data cubes

15.
Polarimetry

cross dipoles
circular feeds
spurious polarization

16. Future developments and science
projects, telescopes
LOFAR, SKA, ALMA, SOFIA, Planck                        
impacts: ISM, IGM, cosmology ...