Algorithm 1 Transformation of the Radar Signal into a 3D Image

Input: Data Matrix $\overrightarrow{R}$ Output: RGB image (PNG format) Procedure Step 1: Collect (2D) radar returns while performing gesture: $\overrightarrow{R}$ Step 2: within $\overrightarrow{R}$, estimate clutter term: $\overrightarrow{C}$ Step 3: Subtract clutter term from radar returns: $\overrightarrow{Z}=\overrightarrow{R}-\overrightarrow{C}$ Step 4: Generate grayscale image of clutter-removed radar returns Step 5: Convert grayscale image into 3D image Step 6: Save 3D image in PNG file format. End procedure Repeat 4–9 for all the samples separately.