History of WSRT

History of WSRT

Here you find a graphical representation of the highlights in the WSRT's rich and exciting history.

  • Telescope inauguration

    Telescope inauguration

    inaugurated by Her Majesty Queen Juliana
    Our 25-m Dwingeloo antenna came into operation in as the world's largest radio astronomy antenna. In April 1956 the telescope was inaugurated by Her Majesty Queen Juliana.
  • Building the world's most powerful radio imager for astronomy

    Breaking ground

    Building the world's most powerful radio imager for astronomy

    After several years negotiation led by Jan Oort to build the Benelux Cross Antenna Project, Belgium finally decided to pull out of the project.

  • Building WSRT

    Building WSRT

    Design and build WSRT
    The Westerbork Synthesis Radio Telescope (WSRT) was designed and built. 
  • WSRT 1968

    Surveying the radio sky

    A mere four years after first breaking ground, WSRT began surveying the radio sky.

  • Starting WSRT

    WSRT begins operations

    The most powerful radio telescope in the world
    The WSRT began operations and for over a decade was the most powerful radio telescope in the world. To mark the widening of the science made possible, the organization's name was changed to the Netherlands Foundation for Radio Astronomy.
  • Taking advantage of the WSRT

    Taking advantage of the WSRT

    Jan Oort was quick to take advantage of the new instrument and his observations with WSRT showed that the well known X-ray source SCO-X1, was, in fact, three sources!  It was the fine angular resol

  • Gas, stars and spiral arms

    Gas, stars and spiral arms

    Jan Oort continued to make discoveries with WSRT, showing for the first time a radio image of the spiral arms of a galaxy. This meant that both gas and stars follow the structure of the spirals, bu

  • Revolutionizing data processing

    Revolutionizing data processing

    Jan Högbom, one of the pioneer developers of the WSRT, continues improvements with the invention of the CLEAN algorithm for making images using aperture synthesis.  This was a revolution in data pr

  • Less dependent on Leiden

    Less dependent on Leiden

    After it becomes possible to buy minicomputers, computer facilities in Groningen and Dwingeloo are updated to become less dependent on the mainframe computer in Leiden.

  • Aperture Synthesis

    Aperture Synthesis

    Approaching the first decade of operations with WSRT, a great wealth of expertise has accumulated at WSRT and its associated labs at Dwingeloo, Leiden, and Groningen.

  • The great "Fixing Project"

    The great "Fixing Project"

    The years inflict their wear-and-tear on the WSRT and the reflector surface from the 25m antennas begin to separate from their frames.

  • The first digital correlator

    The first digital correlator

    Albert Bos, WSRT's "Mr. Correlator" develops the first digital correlator using integrated circuit chips developed.

  • First VLBI observations

    First VLBI observations with WSRT

    VLBI (Very-Long-Baseline-Interferometry) is a technique that uses an array of telescopes to study small radio sources.

  • WSRT is on its own!

    WSRT is on its own!

    Software is developed which makes it possible to judge the overall quality of the observations with the WSRT on site.

  • Confirming earlier optical measurements

    Confirming earlier optical measurements

    Radio images from WSRT of the galaxy NGC3198 show convincingly that Dark Matter dominates the galaxy, confirming earlier, less precise, measurements by optical telescopes.

  • VLBI interface equipment

    Hydrogen Maser frequency standard

    The Wideband VLBI-adding system and MKIII tape recorder using the DCB continuum correlator and new hydrogen maser.

  • The Westerbork Northern Sky Survey (WENSS)

    The Westerbork Northern Sky Survey (WENSS)

    The Westerbork Northern Sky Survey (WENSS) begins, leading to a large catalog of sources used by many researchers around the world. 

  • The Measurement Equation

    The Measurement Equation

    WSRT radio astronomers Hamaker, Bregman, and Sault develop the Measurement Equation technique for calibrating data and removing interference coming from non astronomical sources, including from imp

  • Pulsar timing with PuMa

    Pulsar timing with PuMa

    The WSRT enters the time domain with its first observations of pulsars using the newly installed Pulsar Machine (PuMa).

  • Multi Frequency Front End (MFFE)

    Multi Frequency Front End (MFFE)

    The Multi Frequency Front Ends are installed at WSRT making a vast improvement in performance.

  • Helping out NASA

    Helping out NASA

    The WSRT is used in an experiment to determine if the missing Mars Polar Lander (MPL) from NASA is still “alive”.

  • WSRT steals the show

    WSRT steals the show

    WSRT is the star of the film "Discovery of Heaven" directed by Jeroen Krabbé, and based on the book by Harry Mulish.

  • Studying early-type galaxies

    Studying early-type galaxies

    The WSRT Programme Committee decides to allocate a considerable amount of observing time to observe neutral hydrogen in a large sample of early-type galaxies, until then believed to be depleted of

  • Rotation Measure Synthesis

    Rotation Measure Synthesis

    WSRT astronomers Michiel Brentjens and Ger de Bruyn invent the method of Rotation Measure Synthesis opening up a new view of the polarized sky.

  • Preparing for the Low Frequency Array (LOFAR)

    Preparing for the Low Frequency Array (LOFAR)

    A Low Frequency Frontend is added and WSRT undertakes a survey of the sky at low frequencies.

  • Galileo


    Preparations start to suitably modify one of the telescopes of the WSRT array in order to support the early assessment of Galileo, the Global Navigation Satellite Service.

  • Opening LOFAR

    Opening LOFAR

    Openend by H.M. Queen Beatrix
    On the 12th of June 2010, the International LOFAR telescope was officially opened by Queen Beatrix of the Netherlands during a special ceremony.
  • Albert Einstein 1947

    Verifying Einstein's Principle of Equivalence

    After the discovery of a pulsar in a three body system, WSRT participates in a long campaign of high precision timing of the pulses.

  • Expanding field of view

    Expanding field of view

    After years of pioneering development by ASTRON engineers, the new technology of Phased Array Feeds are installed in 12 of the WSRT dishes.