Fig. 1. Optical overall structure of alkane concentration remote sensing measurment system

Fig. 2. Transmission aspheric collimator lens and adjustment structure

Fig. 3. Transmission aspheric collimator lens and adjustment structure

Fig. 4. Reflector 2 and its fixed structure

Fig. 5. Design of emission mirror

Fig. 6. Schematic diagram of classic Cassegrain system

Fig. 7. Receiving optical path

Fig. 8. Structure of laser collimation system

Fig. 9. Spot diagram of launch system

Fig. 10. Schematic diagram of emission spot at different positions

Fig. 11. Simulation analysis of solar irradiation

Fig. 12. Focus point column diagram of optical system under ideal conditions and after loading temperature changes

Fig. 13. Force analysis of primary mirror

Fig. 14. Laboratory indicator testing using collimator

Fig. 15. Methane absorption signal and harmonic signal

Fig. 16. Ethane absorption signal and harmonic signal

Fig. 17. Hollow reflector at terminal