Inverse variance weighted spherically averaged power spectrum of transient RFI in the presence of thermal noise. Different markers (and colours) show transient RFI cross-power spectra for different thermal noise levels and the dashed lines correspond to the 1σ error due to the thermal noise. We note that the k-values for 500 h and 3000 h have been shifted slightly to better visualise the error bars. The dashed lines also correspond to the power spectrum sensitivity of the given integration time and instrument sensitivity.