Diagnostic plot showing detected burst from RRAT J1819 − 1458 and RFI signal. The upper-left panel is a DM-time gray map generated by de-dispersing the signal with DM varying from 0.7 to 300.7 pc cm^-3 in steps of 1 pc cm^-3. The brightness of the plot indicates the amplitude at the corresponding position, and, the two bright marks at around DM = 195.7 and DM = 0 pc cm^-3 represent the burst and RFI. The upper-right panel is a DM–SNR graph with two peak SNR values at around DM = 195.7 and DM = 0 pc cm^-3, in which the SNR for each DM is calculated from the bin of maximum amplitude over 512 ms. The lower-left panel is a time series graph showing the amplitude (in an arbitrary unit) of each bin at DM = 195.7 pc cm^-3, which clearly delineates a narrow burst profile at the center.