ASTRON & IBM Center for Exascale Technology

The Computer Science challenge of calibrating the ionosphere over the SKA sky

The international SKA radio telescope will have a major impact on our understanding of the formation and evolution of structure in the universe. However, the compute challenges faced by the SKA project are staggering. One of the hardest problems - also in  terms
of computer resources - is how to calibrate the ionosphere to the level required by the science.

The focus of  the  PhD project is to build an ionospheric calibration software test-bed with which we will (i) investigate the complexity of the existing algorithms in space and time, (ii) identify bottlenecks that prevent scaling to larger data volumes, (iii) study how to modify and/or replace (parts of) the existing algorithms to overcome malicious scaling, (iv) design, implement and test such modifications or replacements.

The research will be  carried out as part of a collaboration between Leiden Observatory, Leiden Institute of Advanced Computer Science (LIACS) and  ASTRON/IBM’s DOME project. The student will be hosted at Leiden observatory, but frequent long visits to the partner institutes are foreseen.

Leiden Observatory, founded in 1633, is the oldest university astronomy department in the world. With about 25 faculty, over 50 postdoctoral associates and about 70 PhD students it is the largest astronomy department in the Netherlands.
LIACS is the computer science institute of Leiden University, engaged in both research and education in the area of computer science,
An important focus are the developments of methods and techniques for the design, implementation and application of advanced computer systems, in particular parallel, distributed and embedded computer systems. Leiden is a charming university town with an international flair. Most Leiden researchers have an international background. English is the common language.

Dome is the ASTRON & IBM Research Center for Exascale Technology, located in Dwingeloo, Drenthe on the Campus of ASTRON, the Netherlands Institute for Radio Astronomy. At this centre ASTRON and IBM jointly carry out fundamental research into technologies needed to develop the SKA radio telescope in the later half of this decade and the first half of the next decade.

During their thesis, Leiden  PhD students are paid as civil servants, which means that they earn competitive salaries (the current annual gross salary, including allowances, increases from about EUR 28,000 in year 1 to about EUR 36,000 in year 4) and are eligible for both social security and retirement benefits. PhD positions are funded for four years.

The successful candidates must have a relevant MSc degree (or equivalent).

Application forms and instructions are available at

Applicants are requested to upload a curriculum vitae, a list of all university courses taken and transcripts of grades obtained, brief statements of research interests and experience, and the contact information for at least two referees.

For more information, please contact Prof. Huub Rottgering (Leiden Observatory,,  Prof. Joost Kok (LIACS, or
Dr. Albert-Jan Boonstra (, DOME)

Complete applications received by November 15, 2014 will receive full consideration.