Lofar Deep Imaging And Prospects For Detecting The Eor

One of the most exciting projects to be undertaken with LOFAR is the search for redshifted 21cm signals from the Epoch of Reionization (EoR). It is also one of the most challenging and difficult radio projects ever undertaken. Hundreds of hours of integration, in the band between 115 and 190 MHz, corresponding to HI redshifts between 6.5 and 11.5, will be needed to detect the feeble signals, many orders of magnitude below the signals generated by extragalactic discrete sources and the disk and halo of our Galaxy. In the spring of 2011 we have used the LOFAR telescope to conduct extensive commissioning observations with a still incomplete LOFAR towards two 'EoR-windows'. These observations were used to test the various RFI-excision, calibration and imaging algorithms and finetune the pipelines that will be used for the dataprocessing. A dedicated CPU/GPU cluster at the University of Groningen is used for that purpose. The two windows are located at the North Celestial Pole and on the bright compact quasar 3C196 in a cool area of the Galactic halo. Typical LOFAR observations last 6 hours and are conducted completely at night. New observations, with an improved LOFAR, will commence in the Autumn of 2011. Thusfar we have achieved the deepest low frequency images ever recorded; current noise levels are well below 1 mJy and the image dynamic range exceeds 200,000:1. We will briefly discuss the science goals of the LOFAR EoR project, our near term and longer term plans, and present results from the Spring and Autumn observations. We will also discuss the adopted calibration and processing strategy and how we plan to correct for effects due to ionospheric non-isoplanaticity and sidelobe confusion.