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 06 01 HartRAO technician Lerato Masongwa assembles the 12GHz test receiver for XDM. Its diminutive feedhorn, a scaled down version of that designed by EMSS for 1.5GHz, is visible on the left.
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2007 06 04 Frikkie Badenhorst of IST ponders the antenna control software for XDM.
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2007 06 05 HartRAO engineer Keith Jones and microwave technician Ronnie Myataza calibrate the 12GHz receiver for XDM.
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2007 06 05 Margie Campbell of IST tests the antenna control software while assembly of subsystems continues behind her.
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2007 06 05 Installation work continues on XDM.
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2007 06 06 Ronnie Myataza fills the cold load for calibrating the 12GHz receiver with liquid nitrogen.
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2007 06 06 The eccosorb in the cold load seen through the boiling liquid nitrogen.
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2007 06 06 Ronnie Myataza, Lerato Masongwa and Paul Radingwane calibrate the 12GHz receiver for XDM with the cold load. The metal box on the right houses the receiver; the feed horn is inside the cold load.
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2007 06 07 Calibration of the 1.5GHz test receiver for XDM by Ronnie Myataza, Keith Jones and Lerato Masongwa at HartRAO. The receiver is in the left foreground with its lid removed. It is connected to an AIL hot-cold load at far left.
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2007 06 11 Debugging telescope control software takes time... Frikkie Badenhorst and Margie Campbell of IST.
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2007 06 12 Outdoor testing of the 12 GHz test receiver for XDM. The receiver has a shield to keep ground radiation out of view of the feed. Ronnie Myataza and Lerato Masongwa take the measurements.
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2007 06 19 Surveying the surface of XDM to assess its shape.
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2007 06 22 Rob Adam, chair of the South African SKA committee and second from right in the picture, visits XDM. He is seen with KAT and IST staff working on XDM.
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2007 06 27 Pulsars will be a key research area for the Karoo Array Telescope and here Jocelyn Bell-Burnell, the discoverer of pulsars, visits XDM. On her right are HartRAO / University of Witwatersrand PhD student Sarah Buchner, who is doing her research on pulsars, and HartRAO star formation researcher Sharmila Goedhart.
Find out more about the SKA and KAT at www.ska.ac.za