Fig. 1. Extended target coordinate system for photon ranging

Fig. 2. Three kinds of targets and their respective photon echoes in the attitude angle range from 0° to 90°. (a) Three kinds of targets; (b) target echoes in the range from 0° to 30°；(c) target echoes in the range from 30° to 60°；(d) target echoes in the range from 60° to 90°

Fig. 3. Waveform similarity of any two photon echoes at 0°360° attitude angle. (a) F18; (b) F22; (c) F35

Fig. 4. Variation of average echo waveform difference of three targets with attitude angle interval

Fig. 5. Attitude influence level of echo waveform difference. (a) Photon echo waveform difference at any attitude angle interval; (b) attitude influence level distribution function

Fig. 6. Attitude influence level of kurtosis difference. (a) Photon echo kurtosis difference at any attitude angle interval; (b) attitude influence level distribution function

Fig. 7. Attitude influence level of skewness difference. (a) Photon echo skewness difference at any attitude angle interval; (b) attitude influence level distribution function

Fig. 8. Attitude influence level of central moment difference. (a) Central moment difference of photon echo at any attitude angle interval; (b) attitude influence level distribution function

Fig. 9. Experimental equipment and target models. (a) Experimental field photo; (b) three-dimensional point cloud image of J-15; (c) three-dimensional point cloud image of SU-35

Fig. 10. Attitude influence level of echo difference of experimental targets. (a) Attitude influence level distribution function of echo waveform difference；(b) attitude influence level distribution function of central moment difference; (c) attitude influence level distribution function of kurtosis difference; (d) attitude influence level distribution function of skewness difference