Observed Variation of Three-dimensional Return Stroke Speeds Along the Channel in a Triggered Lightning

<p>In a manuscript entitled &ldquo;Observed Variation of Three-dimensional Return Stroke Speeds Along the Channel in a Triggered Lightning&rdquo;, the lightning&nbsp;data obtained by&nbsp;the Photron SAZ high-speed video and an improved VHF location system were analyzed. The data of our results are including in the Fig_x.figs. These files can be opened by MATLAB. The data supports the aforementioned manuscript and can be used freely for scientific purposes with appropriate citation.</p>