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    JBO’S comments clearly state they have done detailed mapping and this one development increases the interference from a 40km area by 10%!! Also the largest and nearest developments to JBO cause them the most harm..

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    Prof Garrington’s statement in CEC’s evidence is very clear:-

    “…Interference is correlated with human activity, whether due to intentional transmissions or unintentional leakage from a wide range of electrical and electronic devices. The amount of interference received at the telescope from a given location depends on the distance from the telescope and the intervening terrain as well as the strength of the emission itself. JBO has constructed detailed maps of the loss due to distance and terrain based on digital elevation data supplied by the Ordnance Survey and internationally recognised propagation models (ITU P.452). The calculations take into account diffraction over the terrain profile from each location to the focus of the Lovell Telescope and assume a frequency of 1.4 GHz, one of the key protected bands for radio astronomy and the typical observing frequency for the Lovell Telescope.
    This analysis confirms that the proposed development itself is likely to generate interference which exceeds the internationally agreed threshold for what constitutes ‘detrimental interference’ to radio astronomy observations. This threshold is defined by the International Telecommunications Union in ITU-R 769 and is used in national and international spectrum policy negotiations.

    This work has now been extended in order to put the potential emission from a proposed development in context of existing developments across a wide area (up to 40km from JBO). Again using high-resolution digital mapping from the Ordnance Survey the distribution of buildings can be overlaid on the radio loss map. In order to assess the relative contribution from different locations, the number of buildings and their area can be used as an indicator of the potential for radio interference. Hence estimates can be made for the potential interference arising from all development as a function of distance and direction from the telescope.
    According to this analysis the proposed development could increase the total potential interference in that sector (10 degrees wide, out to 40km) by at least 10%. This is a significant contribution even as a single development and JBO would therefore oppose this development…”

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