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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2008 10 30 The KAT-XDM receivers were calibarated using the hot-cold load method, with the sky providing the cold load and eccosorb microwave absorber the hot load. Here Adriaan Peens-Hough takes measurements at the XDM console in the HartRAO control room.
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Pieter Stronkhorst controls the crane hoisting the aborber while Andrew Masiteng and Jacques Grobler steady it and Keith Jones keeps a watchful eye on it.
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A gusty breeze made control of the absorber box tricky.
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Everyone stands clear as the load rises.
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The load is lowered carefully past the top quadripod leg.
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Andrew and Jacques steady the unfurled ropes.
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Almost in position.
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Careful control was needed to stop the fragile absorber pyramids hitting the microwave feedhorns.
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More careful positioning.
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Back in the control room, these are the racks of equipment for signal processing.
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Ruby van Rooyen watches Adriaan start measurements with the absorber in place.
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Pieter Stronkhorst with Willem Esterhyuse. Behind them, the crane provides a fixed attachment for one rope steadying the absorber.
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Closup of the absorber in place.
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Absorber in front of the feeds.
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Absorber twisting in the breeze.
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The light truck provided the other fixed support point for the absorber.
Find out more about the SKA and KAT at www.ska.ac.za