Fig. 1. Relationship among number of equivalent scattering centers N, speckle contrast C, and phase standard variation σ?. (a) C versus σ?; (b) C versus N

Fig. 2. Schematic of millimeter-wave holographic imaging for random rough surface

Fig. 3. Relationship between number of equivalent scattering centers N and correlation length l (k is constant)

Fig. 4. Relationship among speckle contrast C, root mean square height δ of Gaussian rough surface, and correlation length l when L=4λ. (a) C versus kδ for various values of kl; (b) C versus kl for various values of kδ

Fig. 5. Influence of resolution L on speckle contrast C. (a) kl=10; (b) kδ=1

Fig. 6. One imaging result of speckle pattern generated by random rough surface imaging simulation (kδ=0.8,L≈2.51λ). (a) l=0.15λ; (b) l=λ; (c) l=2.5λ

Fig. 7. Comparison of simulation results of millimeter-wave holographic speckle contrast (kδ=0.8,L≈2.51λ)