Low frequency interferometry is a field in radio astronomy with revived interest due to the emergence of capable new software defined radios. The LOFAR (www.lofar.org), LWA and PAPER projects are examples of professional projects in this field. While the scale of these professional projects is well beyond the scope of an amateur, my hope is that some of the elements of these projects can be be successfully achieved on a more limited scale. LOFAR (and other similar arrays) are designed to observe astronomical phenomena at frequencies between 10 and 250 MHz using thousands of simple, inverted V (or similar) antennas.
At low frequencies (10 to 50 MHz), the radio sky is very bright. It follows a power law of ~v^-2.55, such that galactic radio-noise limited reception is possible with simple, low gain antennas with a wide filed of view. Because of the bright radio sky, ground noise is insignificant and the need to track sources as they move across the sky is unnecessary.
For background on low frequency radio interferometry systems currently in use, see the following links:
http://www.phys.unm.edu/~lwa/index.html