Top and bottom-left panels: plots of the SEFD as a function of frequency for the various LOFAR operating bands and station configurations. These curves are derived using the procedure described in Sect. 12.6. The grayed regions are excluded from plotting due to strong post-flagging RFI contamination. In the case of HBA, the circles are for core stations and squares are for remote stations. In the LBA, the circles are LBA_INNER core stations and the squares are LBA_OUTER core stations. Bottom-right panel: contribution of sky temperature to the total system temperature of the LOFAR LBA system. Values are plotted separately for the LBA_INNER (circles) and LBA_OUTER (squares) station configurations. Empirical system temperature values and sky temperatures were determined as described in the text. The LBA system is clearly sky dominated at frequencies below ≈65 MHz. Above that frequency, the instrumental noise term dominates.