Author Affiliations
State Key Laboratory of Pulsed Power Laser Technology, Electronic Engineering Institute, Hefei, Anhui 230037, Chinashow less
Fig. 1. Time-frequency images of laser echo signal of three types of aircraft. (a) Helicopter; (b) propeller; (c) turbojet aircraft
Fig. 2. Pretreatment flow of time-frequency diagram
Fig. 3. Comparison of effect of gray scale before and after denoising. (a) Helicopter before denoising; (b) propeller before denoising; (c) turbojet aircraft before denoising; (d) helicopter after denoising; (e) propeller after denoising; (f) turbojet aircraft after denoising
Fig. 4. GLCM of time-frequency image of three types of aircraft. (a) Helicopter 0°; (b) propeller 0°; (c) turbojet aircraft 0°; (d) helicopter 90°; (e) propeller 90°; (f) turbojet aircraft 90°
Fig. 5. Change curves of GLCM features with different d. (a) C; (b) E; (c) H; (d) I; (e) V
Fig. 6. Tamura feature distribution of three types of aircraft
Fig. 7. Influence of noise on classification accuracy rate. (a) GLCM feature; (b) Tamura feature
Fig. 8. Comparison of classification performance of two kinds of feature under different SNR conditions
Feature parameter | Algorithm | Range |
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Correlation | | [-1,1] | Angular second moment (ASM) | | [0,1] | Entropy | | [0,1] | Contrast | | [0,(G-1)2] | Homogeneity | | [0,1] |
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Table 1. GLCM feature parameter extraction algorithm
Aircraft | Correlation | ASM | Entropy | Contrast | Homogeneity |
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0° | 90° | | 0° | 90° | | 0° | 90° | | 0° | 90° | | 0° | 90° |
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Helicopter | 0.0077 | 0.0098 | 0.82 | 0.83 | 0.95 | 0.88 | 57.44 | 12.50 | 0.91 | 0.93 | Propeller | 0.0026 | 0.0027 | 0.31 | 0.29 | 4.00 | 4.06 | 121.62 | 100.99 | 0.60 | 0.58 | Turbojet aircraft | 0.0118 | 0.0028 | 0.83 | 0.77 | 0.80 | 1.03 | 1.75 | 137.68 | 0.94 | 0.89 |
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Table 2. GLCM feature parameter values
Aircraft | Fcrs | Fcon | Flin |
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Helicopter | 35.90 | 0.059 | 0.90 | Propeller | 22.03 | 0.225 | 0.64 | Turbojet aircraft | 22.75 | 0.073 | 0.87 |
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Table 3. Tamura feature parameter values
Category | Rotating speed /(r/min) | /m | /m | Number of blade | Category | Rotating speed /(r/min) | /m | /m | Number of blade |
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H-1 | 394.0 | 0 | 5.640 | 2 | P-3 | 1150.0 | 0.23 | 1.675 | 4 | H-2 | 265.0 | 0 | 7.800 | 4 | P-4 | 1800.0 | 0.10 | 1.065 | 5 | H-3 | 394.0 | 0 | 5.345 | 3 | P-5 | 800.0 | 0.49 | 2.350 | 4 | H-4 | 265.5 | 0 | 8.150 | 4 | P-6 | 1380.0 | 0.28 | 1.905 | 6 | H-5 | 185.0 | 0 | 10.650 | 5 | P-7 | 2180.0 | 0.17 | 0.915 | 2 | H-6 | 324.0 | 0 | 7.315 | 2 | P-8 | 1690.0 | 0.23 | 1.180 | 3 | H-7 | 205.0 | 0 | 9.450 | 6 | T-1 | 3520.0 | 0.38 | 1.100 | 38 | H-8 | 383.0 | 0 | 5.500 | 4 | T-2 | 8615.0 | 0.18 | 0.510 | 27 | H-9 | 400.0 | 0 | 4.875 | 3 | T-3 | 3000.0 | 0.30 | 1.000 | 30 | P-1 | 950.0 | 0.28 | 1.905 | 6 | T-4 | 5000.0 | 0.20 | 0.600 | 33 | P-2 | 1650.0 | 0.12 | 1.150 | 5 | T-5 | 4000.0 | 0.24 | 0.800 | 42 |
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Table 4. Simulation parameters of five turbojet aircrafts (T), eight propeller aircrafts (P) and nine helicopters (H)