What Will the Next Generation Radio Telescope Detect at 1.4 GHz?

An international project is underway to design and build a radiotelescope with an effective collecting area two orders of magnitude greaterthan the largest existing instruments. One of the many scientific goals of thisinstrument will be the investigation of the extragalactic radio sourcepopulation at flux densities two to three orders of magnitude fainter thanthe limits of existing observations. We present simulations of the radiosky at 1.4 GHz down to a flux density limit of 0.1 μJy usingextrapolations of known radio luminosity functions for two differentpopulation scenarios. The resulting simulations confirm that a resolutionof 0''.1 is necessary to avoid formal confusion, but sourceblending may still dominate if the intrinsic size of such faint sourcesis larger than a few kiloparsecs.