Fig. 1. Principle of laser absolute gravimeter^[2]

Fig. 2. Composition of laser absolute gravimeter

Fig. 3. JILA absolute gravimeter^[3]

Fig. 4. FG5 and FG5X absolute gravimeters from Micro-g Lacoste company^[5-6]

Fig. 5. IMGC02 absolute gravimeter^[8]

Fig. 6. FGC cam type absolute gravimeter^[9]

Fig. 7. NIM-3A absolute gravimeter

Fig. 8. Basic principle. (a) Stimulated Raman transition; (b) schematic of atomic interference

Fig. 9. Schematic of working principle of atom interferometry absolute gravimeter

Fig. 10. Atomic interference fringes^[29]

Fig. 11. System structure diagram of atom interferometry absolute gravimeter^[30]

Fig. 12. Vacuum system of NIM-AGRb-1 atom interferometry absolute gravimeter ^[29]

Fig. 13. Schematic of optical system of NIM-AGRb-1 atom interferometry absolute gravimeter

Fig. 14. Schematic of a small optical system. (a) Schematic of a small optical system developed by the French space agency group^[39]; (b) laser frequency distribution

Fig. 15. Long term gravity measurement data. (a) Long term gravity measurement data of NIM-AGRb-1 atom interferometry absolute gravimeter; (b) experimental data and theoretical difference ^[28]

Fig. 16. Allan variance of NIM-AGRb-1 gravity measurement data^[28]