Fig. 1. Flow diagram of noise reduction pretreatment

Fig. 2. Comparison of noise reduction pretreatment effects. (a) Original signal; (b) signal set negative; (c) after Gaussian filter; (d)-(f) partially enlarged signal

Fig. 3. Probability density function (PDF) of noise under different filter window lengths. (a) ℏ=4; (b) ℏ=9; (c) ℏ=15

Fig. 4. Estimating schematic of protective unit

Fig. 5. Curve of variance

Fig. 6. Detection performance curves. (a) Detection performance curves of ABG-CFAR method before and after preprocessing; (b) detection performance curves of three methods

Fig. 7. Experimental scene and target detection effect. (a) Experimental scene; (b) target detection effect in a channel

Fig. 8. Two-dimensional point cloud image of experimental data. (a) Before preprocessing; (b) after preprocessing

Fig. 9. Detection results. (a) D-CFAR and BG-CFAR; (b) ABG-CFAR

Fig. 10. Target detection probability and Monte Carlo statistical results. (a) Target detection probability; (b) Monte Carlo statistical results