Fig. 1. Block diagram of laser emission and monitoring system^[10]

Fig. 2. Images taken by LFC in synchronous exposure mode

Fig. 3. Spot images in asynchronous mode. (a) Ground image 1; (b) spot image; (c) ground image 2

Fig. 4. Flowchart of spot center positioning

Fig. 5. Spot image without noise

Fig. 6. Typical gray histograms of different types of images. (a) Spot image; (b) weak noise image; (c) moderate noise image; (d) strong noise image

Fig. 7. Typical example of test image. (a) Test image of weak noise; (b) test image of moderate noise; (c) test image of strong noise

Fig. 8. Error scatter distribution of Gaussian fitting center location method under different noise conditions. (a) Weak noise image; (b) moderate noise image; (c) strong noise image

Fig. 9. Error scatter distribution of Gaussian fitting center location method at night