Step 1: Range profiles are collected by flying the drone across the scene in a straight line (at approximately 2 m above the ground). The closest approach, Rmin, is approximately 7.5 m.
Step 2: Plot the measured range profiles vs. flight time.
Step 3: Translation motion compensation is first carried out by aligning to a prominent point-scatterer on the range profiles vs. flight time.
Step 4: To relate measurement time with the azimuth angle 𝜃, we assume the flight path is straight and use the relationship 𝜃 = cos−1(𝑅𝑚𝑖𝑛/𝑅), where R is the range at each instance in time, and Rmin is the minimum range.
Step 5: Applying a Fourier transform to the range axis, the range profiles vs. azimuth are transformed into frequency responses vs. azimuth.
Step 6: Based on the k-space imaging theory, a two-dimensional (2-D) image of the scene can be formed by a 2-D inverse Fourier transform of the collected frequency-azimuth backscattered data.