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		| Paper: | 
		LOFAR Self-Calibration using a Local Sky Model | 
	 
	
		| Volume: | 
		351, Astronomical Data Analysis Software and Systems XV | 
	 
	
		| Page: | 
		291 | 
	 
	
		| Authors: | 
		Nijboer, R.J.; Noordam, J.E.; Yatawatta, S.B. | 
	 
	
	
		| Abstract: | 
		LOFAR Self-Calibration will be based on adaptive models. This means that instrumental, ionospheric, and sky parameters are fitted to the measured data using a Measurement Equation (ME). One of the deliverables of LOFAR will thus be a Global Sky Model (GSM) that will be an all-sky database of some 100 million objects characterised by position, shape, flux, and polarization. Once a (crude) GSM is constructed it will be updated by fitting it to new measured data. The part of the GSM that is relevant for the processing of a particular dataset is put in a Local Sky Model (LSM). There it is combined with relevant observational data and used in the Self-Calibration process. In this presentation the design and implementation of the Local Sky Model within the MeqTree System (a new module for Self-Calibration) is discussed. Initially processing will be based on Point Sources and Imaged Sources. This results in a different treatment of the two types. | 
	 
	
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