In order to develop a laser system for multi-wavelength satellite laser ranging, the joint group of the Shanghai Astronomical Observatory and the Czech Technical University has studied the conversion efficiency of the...In order to develop a laser system for multi-wavelength satellite laser ranging, the joint group of the Shanghai Astronomical Observatory and the Czech Technical University has studied the conversion efficiency of the Raman-shifting beam and its spatial characteristics. We adopted a 0.53 μm laser with pulse width of 35 ps and peak energy of 35 mJ, the second harmonic of a Nd:YAG actively and passively mode-locked laser, to pump a one-meter-long Raman tube which is full of H2 with high pressure at the Prague-based laboratory. We get the first Stokes laser (0.68 μm): 7 mJ (single pulse) with beam divergence of 40″ (arcsecond) and spatial wobbling of less than 4″; and the first anti-Stokes laser (0.43 μm): 2 mJ (single pulse) with divergence of 56″ and spatial wobbling of less than 4″. The emitting beam from the Raman cell also includes 0.53 μm: 10 mJ (single pulse) with divergence of 40″ and spatial wobbling of less than 7″. According to the radar link equation and based on the above obtained multi-wavelength’s energy, we can estimate the detection probabilities for three colors respectively. It is shown by the result that the developed multi-wavelength Raman laser system has the capability of satellite ranging. The Raman laser system will be installed at the laser station in Shanghai Astronomical Observatory to research the multi-wavelength satellite laser ranging.展开更多
The Shanghai Astronomical Observatory, Chinese Academy of Sciences, incollaboration with the Czech Technical University, carried out the experiment of satellite laser ranging with sub-centimeter precision in Shanghai ...The Shanghai Astronomical Observatory, Chinese Academy of Sciences, incollaboration with the Czech Technical University, carried out the experiment of satellite laser ranging with sub-centimeter precision in Shanghai in August 2001. A pico-second event timer was used for the measurement of the time interval between the transmitted and returned laser pulses for Lageos 1, 2, Starlette, Stella, Topex/Poseiden and ERS-2 in coordination with the existing laser transmitting and receiving system at the Shanghai Observatory. The analysis of the measurement showed that the single-shot ranging precision with these satellites is 7-8 mm. In order to compare ranging precision, the existing ranging system has tracked simultaneously these satellites and obtained the ranging precision of 12-15 mm. It means that the ranging precision with the new system is 80% better thanthe existing system. The systematic biases with the existing system have also been checked in the experiment.展开更多
基金This research is supported by the National Natural Science Foundation of China (Grant Nos. 10373022, 10173018).
文摘In order to develop a laser system for multi-wavelength satellite laser ranging, the joint group of the Shanghai Astronomical Observatory and the Czech Technical University has studied the conversion efficiency of the Raman-shifting beam and its spatial characteristics. We adopted a 0.53 μm laser with pulse width of 35 ps and peak energy of 35 mJ, the second harmonic of a Nd:YAG actively and passively mode-locked laser, to pump a one-meter-long Raman tube which is full of H2 with high pressure at the Prague-based laboratory. We get the first Stokes laser (0.68 μm): 7 mJ (single pulse) with beam divergence of 40″ (arcsecond) and spatial wobbling of less than 4″; and the first anti-Stokes laser (0.43 μm): 2 mJ (single pulse) with divergence of 56″ and spatial wobbling of less than 4″. The emitting beam from the Raman cell also includes 0.53 μm: 10 mJ (single pulse) with divergence of 40″ and spatial wobbling of less than 7″. According to the radar link equation and based on the above obtained multi-wavelength’s energy, we can estimate the detection probabilities for three colors respectively. It is shown by the result that the developed multi-wavelength Raman laser system has the capability of satellite ranging. The Raman laser system will be installed at the laser station in Shanghai Astronomical Observatory to research the multi-wavelength satellite laser ranging.
基金the National Mega-Project of Scientific Engineering"Crustal Movement Observation Network of China"National Climbing Project in Basic Research"Present Crustal Movement and Geodynamics"the Shanghai Science Development Foundation(jc14012)
文摘The Shanghai Astronomical Observatory, Chinese Academy of Sciences, incollaboration with the Czech Technical University, carried out the experiment of satellite laser ranging with sub-centimeter precision in Shanghai in August 2001. A pico-second event timer was used for the measurement of the time interval between the transmitted and returned laser pulses for Lageos 1, 2, Starlette, Stella, Topex/Poseiden and ERS-2 in coordination with the existing laser transmitting and receiving system at the Shanghai Observatory. The analysis of the measurement showed that the single-shot ranging precision with these satellites is 7-8 mm. In order to compare ranging precision, the existing ranging system has tracked simultaneously these satellites and obtained the ranging precision of 12-15 mm. It means that the ranging precision with the new system is 80% better thanthe existing system. The systematic biases with the existing system have also been checked in the experiment.
