Fig. 1. Multi-planes detection model. (a) z direction; (b) y direction

Fig. 2. Echo simulation results of double targets

Fig. 3. Echo simulation results of three targets

Fig. 4. Echo simulation results of three waveforms with different angles. (a) ψ_1;(b)ψ_2;(c) ψ₃

Fig. 5. Experimental platform of multi-target detection. (a) Experimental scene; (b) combined platform

Fig. 6. Influence of field of view on echo power

Fig. 7. Single target echo waveform. (a) Target 1; (b) target 2; (c) target 3

Fig. 8. Double waveform experiment results of target 1 and target 3. (a) A₁＝－1, B₁(A₃)＝0, B₃＝1；(b) A₁＝－1, B₁(A₃)＝－1/3, B₃＝1; (c) A₁＝－1, B₁(A₃)＝1/3, B₃＝1

Fig. 9. Double waveform experiment results of target 2 and target 3. (a) A₂＝－1, B₂(A₃)＝0, B₃＝1；(b) A₂＝－1, B₂(A₃)＝－1/3, B₃＝1; (c) A₂＝－1, B₂(A₃)＝1/3, B₃＝1

Fig. 10. Waveforms with different incident angles of target 3 when laser irradiates target 1 (1/2) and target 3 (1/2).(a) Simulation results; (b) experimental results

Fig. 11. Waveforms with different incident angles of target 3 when laser irradiates target 1 (1/3) and target 3 (2/3). (a) Simulation results; (b) experimental results

Fig. 12. Waveforms with different incident angles of target 3 when laser irradiates target 2 (1/3) and target 3 (2/3). (a) Simulation results; (b) experimental results

Fig. 13. Echo waveforms when laser irradiates three targets at the same time

Fig. 14. Receiving circuit without voltage overshoot

Fig. 15. Normalization results of single echo waveform when the distance between two targets is 1.5 m. (a) Target 1; (b) target 2

Fig. 16. Normalization results of single echo waveform when the distance between two targets is 1 m. (a) Target 1; (b) target 2

Fig. 17. Echo results with distance of 1.5 m between two targets. (a) A₁＝－1, B₁(A₂)＝－1/3, B₂＝1; (b) A₁＝－1, B₁(A₂)＝0, B₂＝1; (c) A₁＝－1, B₁(A₂)＝1/3, B₂＝1

Fig. 18. Echo results with distance of 1 m between two targets. (a) A₁＝－1, B₁(A₂)＝－1/3, B₂＝1; (b) A₁＝－1, B₁(A₂)＝0, B₂＝1; (c) A₁＝－1, B₁(A₂)＝1/3, B₂＝1