Algorithm 1. Transformation of radar signals into images

Receive input signal from radar sensor s$\left(n\right)$. Remove clutter from signal as described in Section 2.3. Low-pass signals are combined into matrix of size $m\times n$ where “m” is slow-time index and “n” is fast-time index. Combine each one-dimensional signal from radar, as shown in Equation (5). Normalize database, as described by Equation (6). Convert normalized 2D matrices into RGB images and then convert it into greyscale images, as shown in Figure 6.