Fig. 1. Relative position relationship between airborne detector and target

Fig. 2. Schematic of migration of feature space

Fig. 3. Dual-color-ratio-feature point distribution under maneuvering mode

Fig. 4. Migration process of feature space under maneuvering mode

Fig. 5. (a) Two-dimensional motion tracks of target and airborne detector; (b) target lateral overloading versus time; (c) target attitude angle versus time; (d) dual-color-ratio-feature versus target attitude angle and lateral overloading

Fig. 6. Dual-color-ratio-feature point distribution under quarter turn maneuver

Fig. 7. Gauss mixture distributions of dual-color-ratio-feature sub-space under different variations of target attitude angle. (a) Δα=50.34°; (b) Δα=36.16°; (c) Δα=14.23°; (d) Δα=3.52°

Fig. 8. Sequential dual-color-ratio-feature point distribution under linear motion

Fig. 9. Gauss mixture distributions of sequential dual-color-ratio-feature sub-space under linear motion. (a) Before adjacent feature sub-spaces merged; (b) after adjacent feature sub-spaces merged

Fig. 10. Sequential dual-color-ratio-feature point distribution under quarter turn maneuver

Fig. 11. Gauss mixture distributions of sequential dual-color-ratio-feature sub-space under quarter turn maneuver. (a) Before adjacent feature sub-spaces merged; (b) after adjacent feature sub-spaces merged

Fig. 12. Sequential dual-color-ratio-feature point distribution under circle maneuver

Fig. 13. Gauss mixture distribution of sequential dual-color-ratio-feature sub-space under circle maneuver