Example of narrowband-type (category I, event no. 17) high-frequency wave. Electric field recorded by LPW instrument on MAVEN spacecraft is plotted as a function of time in milliseconds after the start time of this event, t_start = 06:45:29:160 hh:mm:ss:mss (in UT), fast Fourier spectra of these electric field variations and its spectrograms (frequency-time representation) are plotted in panels a, b, and c, respectively. The black dashed-dotted vertical line in panel b and horizontal line in panel c indicate the upper-hybrid wave estimated from ambient plasma parameters. The spectral peak is well above the 90% statistical significance marked by dashed grey line in panel b. Here, the length of electric field data is 62.5 ms.