Astronomical Data Processing

Course content

Standard processing techniques of generic astronomical imaging and spectroscopic data; for the latter data there will be a focus on long-slit spectroscopy, thereby providing a background for Echelle and Integral Field Spectroscopic processing. Introduction to the fundamental issues related to the planning of data acquisition at the telescope.

Fundamental instructions in processing of astronomical imaging and spectroscopic data, the nature and properties of generic UV-optical imaging and spectroscopic detectors (IR is addressed as time permits) relevant for data processing, and in signal-to-noise computations, noise‐contributions, photon statistics. The purpose aim is to enable the student to single‐handedly process standard imaging and (long-slit) spectral data in future research projects. These competences lay the background for potential future expansion of the competences to more advanced and complex data processing techniques by the student and/or collaborators/advisor.


M.Sc. Physics

Learning outcome

To pass this course the student must:

  • Be able to process both imaging and long‐slit spectral data well enough to allow the student to extract reasonable basic measurements from the data
  • Demonstrate the ability to critically assess the data quality, error sources, the necessary processing and calibration tasks needed at each processing steps, and the goodness/quality of the data processing performed.
  • Perform the necessary basic data processing of raw astronomical UV-optical imaging and spectral data, as presented as part of the course exercises/projects.
  • Perform the necessary calibration of the scientific imaging and spectral data
  • Perform basic analysis of the data such as 1‐D and 2‐D photometry, velocity widths and shifts of spectral lines, line equivalent widths, and continuum fitting.
  • Calculate signal‐to‐noise ratios, generate noise images and spectra, estimate exposure times and plan the basic data taking details for new observations.

Upon satisfactory completion of this course the student will be able to:

  • account for the necessary steps needed to process and calibrate raw astronomical UV-optical imaging and spectral data, as obtained from the telescopes.
  • Explain, justify, and assess each step in the data reduction process and how the data and their quality are evaluated.
  • account for and critically assess the methods used to perform basic analyses and measurements, including accounting for errors, on the data.
  • explain and justify how to calculate the signal-to-noise ratios, estimate exposure times, and can account for the important issues related to obtaining new data at the telescope

This course will provide the students with a basic background on (a) the important aspects of the processing of UV-optical astronomical imaging and (long-slit) spectroscopic data, (b) how to critically assess and evaluate the data quality and sources of error, and on (c) planning and preparing new observations. In addition, the course will provide the students with software tools and techniques on data processing and basic analysis. In concert, these competences and tools can be applied during further studies within astrophysics, for example in a M.Sc. and/or Ph. D project.

These competences also lay the background for further expansion of the competences to more advanced and complex data processing techniques.

Lectures, hands‐on computer projects

Lecture notes and

Steve B. Howell: Handbook of CCD Astronomy, 2nd Edition   (Cambridge Observing Handbooks for Research Astronomers)

This course is highly recommended for Master students in Astronomy and Astrophysics. Students are advised to take this course as one of the very first courses during the Master’s studies.
The student may benefit from having a background equivalent to that covered by the courses ‘Statistical Physics’, ‘Electromagnetism’ (EM1, EM2), ‘Optical Physics and Laser’.

Students are required to bring their own laptops and, if needed, a converter to wired Ethernet, since we work off wired Ethernet.
The following terminal software is necessary:
Windows: Xming software is needed: http:/​/​​projects/​xming/​ & http:/​/​​XmingNotes/​
Help can be obtained from SCIENCE IT: e-mail:, Phone: 35 32 21 00
Linux: the X11 environment is standard and runs automatically.
MacIntosh/MACs: Starting with operating system OS 10.5 the X11 environment can be used. This can be downloaded for free from http:/​/​​landing/​.
For operating systems Leopard and Lion the X11 environment is a part of OS X.

7,5 ECTS
Type of assessment
Written assignment
To pass the course the student must:

- submit a report (minimum of 15 pages) on the data processing of both imaging and spectral data performed in the course. More specifically it should address:

All the necessary steps needed and the reasons for them and how the quality of each processing step is evaluated. The report needs to be approved by the instructors. To be approved, the report itself should be of a sufficient quality that the student or others could use it as a compendium. The report should include a sufficient amount of the material covered in the course for the reader(at the level of a starting Master’s student) to understand with ease the procedures and techniques and why they are performed.
All aids allowed
Marking scale
passed/not passed
Censorship form
No external censorship
More internal examiners
Criteria for exam assessment

See Skills and Exam

Single subject courses (day)

  • Category
  • Hours
  • Lectures
  • 24
  • Practical exercises
  • 40
  • Project work
  • 112
  • Preparation
  • 30
  • English
  • 206