Fig. 1. Schematic diagram of focal length calculation principle

Fig. 2. Schematic diagram of height estimation principle at small angle stage

Fig. 3. Schematic diagram of height estimation principle at large angle stage

Fig. 4. Simulation results of adding different standard deviation pixel Gaussian noise. (a) Height estimation results; (b) rotation angle estimation results

Fig. 5. Experimental setup. (a) Height estimation equipment; (b) non-cooperative flight target

Fig. 6. Images acquired in experiment

Fig. 7. Estimation results of flight height and inclination angle. (a) At small angle stage; (b) at large angle stage