The eXperimental Development Model (XDM) is a 15-m diameter radio telescope antenna prototype for the Karoo Array Telescope (KAT). It is located at the Hartebeesthoek Radio Astronomy Observatory (HartRAO). It is being used to test technology leading up to development of the Square Kilometer Array (SKA).
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2007 09 13 KAT-XDM gets a facelift. The markers used for photogrammetry of the surface were removed and the surface repainted by the IST team.
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2007 09 17 The EMSS team install the mounting for the seven-feed 1.4-GHz test receiver. Two live feed horns are installed, one on axis and on off axis, with dummies in the remaining positions.
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2007 09 18 The seven-feed receiver in place at the prime focus of XDM.
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2007 09 18 Wiring test equipment to the feeds on XDM. The Moon is visible just below the structure.
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2007 09 18 The floodlight calibration signal illuminator being prepared for installation on XDM.
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2007 09 18 In the XDM pedestal Robert Lehmensiek of EMSS studies the data being recorded from the network analyser in the foreground.
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2007 09 19 Adjusting the cabling to the feeds on XDM.
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2007 09 19 The floodlight illuminator and vertex cone installed on XDM. The vertex cone is not a flat plate as might appear. It is designed to minimise signal reflections between the feed mounting and the centre of the antenna.
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2007 09 19 Robert Lehmensiek discusses the reflection pattern measured by the network analyser.
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2007 09 19 KAT-XDM with the seven-feed receiver system at prime focus.
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2007 09 19 Close-up of the seven-feed receiver at the XDM prime focus.
Find out more about the SKA and KAT at www.ska.ac.za