The
low-frequency radio range, due to the absence of photon noise and the
correlation between radio emissions and energetic phenomena, is well
adapted tio the search for transient signals. Some of them may be
related to sources of gravitational waves. I will briefly review
observation methods in the radio range, and their application to the
first new generation low-frequency radiotelescope: LOFAR (the LOw
Frequency ARray). I will present this instrument, revolutionnary by
many aspects, its operations and the policy permitting access to its
data (proposals, key projets, standalone observations, etc.).