| One of the relatively unexplored areas of astronomy is the sub-GHz radio sky at sub-arcminute resolution. The wide fields-of-view of current and future low-frequency radio interferometers (LOFAR, MWA, JVLA, GMRT, SKA-low) make them potentially powerful survey instruments, yet it comes at the cost of significantly increased complexity in the data processing.
One major hurdle is to properly account for the direction-dependent distortions in the presence of large numbers of detectable cosmic sources within the field-of-view and beyond. One essential ingredient is having an accurate reference model of the sky at a similar frequency and resolution.
In this talk I will present methods and results of the fully automated processing of the 37,000 deg^2 archival 150 MHz GMRT sky survey (TGSS) data using the SPAM package. Covering about 90 percent of the radio sky, this ~25'' survey provides an excellent reference catalog for LOFAR and MWA, as well as a unique view on the relatively unexplored southern hemisphere sky, opening up many options to search for interesting objects.