Chang’E-3 landed on the east of Sinus Iridum area on December 14,2013,performing China’s first successful soft landing on the lunar surface.We present the results on precision orbit determination and positioning of ...Chang’E-3 landed on the east of Sinus Iridum area on December 14,2013,performing China’s first successful soft landing on the lunar surface.We present the results on precision orbit determination and positioning of the lander and the rover.We describe the data,modeling,and methods used to achieve position knowledge over the period December 2–21,2014.In addition to the radiometric X-band range and Doppler tracking data,delta differential one-way ranging data are also used in the calculation,which show that they strongly improve the accuracy of the orbit reconstruction.Total position overlap differences are about 20 and 30 m for the 100 km 9 100 km and100 km9 15 km lunar orbit,respectively,increased by*50%with respect to CE-2 and at the same level as other lunar spacecrafts of recent era such as SELENE and lunar reconnaissance orbiter(LRO).The position error of the soft landing trajectory is less than 100 m.A kinematic statistical method is applied to determine the position of the lander and relative position of the rover with respect to the lander.The position difference of the lander is better than50 m compared to LRO photograph result.Compared with the delta very long baseline interferometry(VLBI)group delay between the lander and the rover,the delta VLBI phase delay can improve the relative position of the rover from*1,000 to*1 m.展开更多
The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus...The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus Iridum. The geologic stratigraphic units and crates are interpreted visually based on SELENE Terrain Camera (TC) images and the spatial resolution of which is up to 10 m. And the geologic ages of different stratigraphic units are calculated by the crater size-frequency distributions measurements. The gravity anomaly is generated from SELENE gravity model (SGM90d) to show its difference from Mare Imbrium. Furthermore, the thickness of lunar regolith is also derived from microwave radiometer data of Chang’e-1 satellite. Integrating these results, it shows that the Sinus Iridum is different from the Mare Imbrium in inner structure and surface sedimentation. And its history of subsidence, deposition, volcanism, and impact is described. It makes sense to the future soft-landing and sampling at potential Sinus Iridum by remote sensing geologic analysis.展开更多
When only data transmission signals with a bandwidth of 1 MHz exist in the rover, the position can be obtained using the differential group delay data of the same-beam very long baseline interferometry (VLBI). The rel...When only data transmission signals with a bandwidth of 1 MHz exist in the rover, the position can be obtained using the differential group delay data of the same-beam very long baseline interferometry (VLBI). The relative position between a lunar rover and a lander can be determined with an error of several hundreds of meters. When the guidance information of the rover is used to determine relative position, the rover's wheel skid behavior and integral movement may influence the accuracy of the determined position. This paper proposes a new method for accurately determining relative position. The differential group delay and biased differential phase delay are obtained from the same-beam VLBI observation, while the modified biased differential phase delay is obtained using the statistic mean value of the differential group delay and the biased phase delay as basis. The small bias in the modified biased phase delay is estimated together with other parameters when the relative position of the rover is calculated. The effectiveness of the proposed method is confirmed using the same-beam VLBI observation data of SELENE. The radio sources onboard the rover and the lander are designed for same-beam VLBI observations. The results of the simulations of the differential delay of the same-beam VLBI observation between the rover and the lander show that the differential delay is sensitive to relative position. An approach to solving the relative position and a strategy for tracking are also introduced. When the lunar topography data near the rover are used and the observations are scheduled properly, the determined relative position of the rover may be nearly as accurate as that solved using differential phase delay data.展开更多
Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations ...Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations by taking advantage of automatic observations with self compensation of tilt of the tube.We here propose In-situ Lunar Orientation Measurement(ILOM) to study lunar rotational dynamics by direct observations of the lunar rotation from the lunar surface by using a small telescope like PZT with an accuracy of 1 milli-seconds of arc(1 mas) in the post-SELENE mission.Our second application is to obtain local gravity field on the Earth by combining deflection of the vertical measured by PZT and the position measured by Global Positioning System(GPS) or Global Navigation Satellite System(GNSS).The accuracy required for this purpose is not as strict as ILOM.We have already developed a Bread Board Model(BBM) of the telescope for ILOM and made some experiments in order to know the performance of the driving mechanism under a similar condition to the lunar environment showing high vacuum,large temperature change and dusty condition.We have also shown that it is possible to correct the effects of uniform temperature change upon the optical system by using a simple model with an accuracy of better than 1 mas.This model has the potential to attain the accuracy of 1 mas,based on the results of the experiments and the simulations.展开更多
The first Chinese lunar orbiter Chang'E-1 is a successful mission with many fruitful results obtained in various disciplines. The scientific data acquired by the Chang'E-1 payloads can benefit studies of the l...The first Chinese lunar orbiter Chang'E-1 is a successful mission with many fruitful results obtained in various disciplines. The scientific data acquired by the Chang'E-1 payloads can benefit studies of the lunar origin and evolution, as well as other relevant research areas, after careful validation of the data. Among the new results, the Chang'E-1 selenodetic products are continually uncovering characteristics of the lunar surface, undersurface and inner structure. Successful lunar orbiters such as the Clementine, Lunar Prospector, KAGUYA/SELENE, Chang'E-1, Lunar Reconnaissance Orbiter and GRAIL have been revealing, with increasing clarity, global selenodetic characteristics with state-of-the-art fine resolution and high precision. In particular, the Chang'E-1 plays an important distinctive role in selenodetic exploration through enhancing lunar topography and gravity models. The gravity model has been successfully improved with a factor of two after applying the Chang'E-1 long-wavelength tracking data. Using the new models, some medium-scale lunar surface characteristics such as basins and volcanoes have been identified. Furthermore, the old mascon basins of Bouguer, gravity anomaly and craters have been discovered with the Chang'E-1 selenodetic data.展开更多
Japanese lunar explorer SELENE (KAGUYA) was equipped with 14 instruments for various measurements of the Moon. Three of these instruments took geodetic measurements of the Moon. These were two sub-satellites and a las...Japanese lunar explorer SELENE (KAGUYA) was equipped with 14 instruments for various measurements of the Moon. Three of these instruments took geodetic measurements of the Moon. These were two sub-satellites and a laser altimeter. The main results obtained by the instruments are: (1) precise orbit determination with an accuracy of ten meters by Doppler and same-beam VLBI; (2) the first precise gravity fields on the lunar far side by 4-way Doppler measurements; (3) the first topography in latitudes higher than 86 degrees; (4) a global map of the gravity anomaly by using the global topography and the global gravity fields; (5) a global map of the lunar crustal thickness and (6) an illumination rate map in the north and south polar regions.展开更多
[Objective] The paper was to understand the harms of Actias selene ningpoana Felder to plants. [Method] The larvae were cultured in five different groups: camphor tree, cherry tree, crape myrtle tree, poplar and willo...[Objective] The paper was to understand the harms of Actias selene ningpoana Felder to plants. [Method] The larvae were cultured in five different groups: camphor tree, cherry tree, crape myrtle tree, poplar and willow, to observe the growth status of larvae. [Result] The survival rates of A. selene ningpoana in cherry tree and crape myrtle tree group were higher. The larvae in cherry tree group had faster growth, and the adults were large. [Conclusion] A. selene ningpoana is most harmful to cherry trees, which should be paid special attention in cherry garden.展开更多
A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an ...A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an accuracy of - λ/4 or better, where 2 is the wavelength of the HF radar pulse at its center frequency. The performance of the proposed technique was confirmed by simulation which was carried out under the condition of design facts of the SELENE LRS mission. The highly accurate orbit positioning enables precise superposition of HF SAR images so that the inherent mirror image ambiguity problem of HF SAR imaging is resolved to obtain a quality SAR image of the HF band. In addition ambitious 2D-SAR processing would be possible when the above accuracy is available.展开更多
基金supported by the National Natural Science Foundation of China (11073047,11173052)the Science and Technology Commission of Shanghai (12DZ2273300)+2 种基金the National High Technology Research and Development Program of China (2012AA121603)the Planetary Sciences Laboratory of Chinese Academy of Sciencesthe Lunar Exploration Project of China
文摘Chang’E-3 landed on the east of Sinus Iridum area on December 14,2013,performing China’s first successful soft landing on the lunar surface.We present the results on precision orbit determination and positioning of the lander and the rover.We describe the data,modeling,and methods used to achieve position knowledge over the period December 2–21,2014.In addition to the radiometric X-band range and Doppler tracking data,delta differential one-way ranging data are also used in the calculation,which show that they strongly improve the accuracy of the orbit reconstruction.Total position overlap differences are about 20 and 30 m for the 100 km 9 100 km and100 km9 15 km lunar orbit,respectively,increased by*50%with respect to CE-2 and at the same level as other lunar spacecrafts of recent era such as SELENE and lunar reconnaissance orbiter(LRO).The position error of the soft landing trajectory is less than 100 m.A kinematic statistical method is applied to determine the position of the lander and relative position of the rover with respect to the lander.The position difference of the lander is better than50 m compared to LRO photograph result.Compared with the delta very long baseline interferometry(VLBI)group delay between the lander and the rover,the delta VLBI phase delay can improve the relative position of the rover from*1,000 to*1 m.
基金supported by the National Natural Science Foundation of China(Grant Nos. 40901187 and 40901159) the High-Tech Research and Development Programme (Grant Nos. 2008AA12A212, 2010AA122203)
文摘The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus Iridum. The geologic stratigraphic units and crates are interpreted visually based on SELENE Terrain Camera (TC) images and the spatial resolution of which is up to 10 m. And the geologic ages of different stratigraphic units are calculated by the crater size-frequency distributions measurements. The gravity anomaly is generated from SELENE gravity model (SGM90d) to show its difference from Mare Imbrium. Furthermore, the thickness of lunar regolith is also derived from microwave radiometer data of Chang’e-1 satellite. Integrating these results, it shows that the Sinus Iridum is different from the Mare Imbrium in inner structure and surface sedimentation. And its history of subsidence, deposition, volcanism, and impact is described. It makes sense to the future soft-landing and sampling at potential Sinus Iridum by remote sensing geologic analysis.
基金supported by the Hundred Talent Project(s) of Chinese Academy of Sciencesthe National Natural Science Foundation of China (Grant Nos.11073048 and 11073047)+1 种基金the Pujiang Project of Shanghai (Grant No.10PJ1411700)Shanghai Key Laboratory of Space Navigation and Position Techniques (Grant No.Y054262001)
文摘When only data transmission signals with a bandwidth of 1 MHz exist in the rover, the position can be obtained using the differential group delay data of the same-beam very long baseline interferometry (VLBI). The relative position between a lunar rover and a lander can be determined with an error of several hundreds of meters. When the guidance information of the rover is used to determine relative position, the rover's wheel skid behavior and integral movement may influence the accuracy of the determined position. This paper proposes a new method for accurately determining relative position. The differential group delay and biased differential phase delay are obtained from the same-beam VLBI observation, while the modified biased differential phase delay is obtained using the statistic mean value of the differential group delay and the biased phase delay as basis. The small bias in the modified biased phase delay is estimated together with other parameters when the relative position of the rover is calculated. The effectiveness of the proposed method is confirmed using the same-beam VLBI observation data of SELENE. The radio sources onboard the rover and the lander are designed for same-beam VLBI observations. The results of the simulations of the differential delay of the same-beam VLBI observation between the rover and the lander show that the differential delay is sensitive to relative position. An approach to solving the relative position and a strategy for tracking are also introduced. When the lunar topography data near the rover are used and the observations are scheduled properly, the determined relative position of the rover may be nearly as accurate as that solved using differential phase delay data.
基金supported by the Advanced Technology Center (Grant No. 2009-101)supported by the National Natural Science Foundation of China (Grant No. 10973031)+1 种基金Chinese National High-Tech Project (Grant No. 2009AA122206)the Grant-in-Aid for Scientific Research (B) (Grant No. 22340128)
文摘Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations by taking advantage of automatic observations with self compensation of tilt of the tube.We here propose In-situ Lunar Orientation Measurement(ILOM) to study lunar rotational dynamics by direct observations of the lunar rotation from the lunar surface by using a small telescope like PZT with an accuracy of 1 milli-seconds of arc(1 mas) in the post-SELENE mission.Our second application is to obtain local gravity field on the Earth by combining deflection of the vertical measured by PZT and the position measured by Global Positioning System(GPS) or Global Navigation Satellite System(GNSS).The accuracy required for this purpose is not as strict as ILOM.We have already developed a Bread Board Model(BBM) of the telescope for ILOM and made some experiments in order to know the performance of the driving mechanism under a similar condition to the lunar environment showing high vacuum,large temperature change and dusty condition.We have also shown that it is possible to correct the effects of uniform temperature change upon the optical system by using a simple model with an accuracy of better than 1 mas.This model has the potential to attain the accuracy of 1 mas,based on the results of the experiments and the simulations.
基金supported by the National Natural Science Foundation of China (Grant No.10973031)the National High Technology Research and Development Program of China (Grant No.2010AA122206)
文摘The first Chinese lunar orbiter Chang'E-1 is a successful mission with many fruitful results obtained in various disciplines. The scientific data acquired by the Chang'E-1 payloads can benefit studies of the lunar origin and evolution, as well as other relevant research areas, after careful validation of the data. Among the new results, the Chang'E-1 selenodetic products are continually uncovering characteristics of the lunar surface, undersurface and inner structure. Successful lunar orbiters such as the Clementine, Lunar Prospector, KAGUYA/SELENE, Chang'E-1, Lunar Reconnaissance Orbiter and GRAIL have been revealing, with increasing clarity, global selenodetic characteristics with state-of-the-art fine resolution and high precision. In particular, the Chang'E-1 plays an important distinctive role in selenodetic exploration through enhancing lunar topography and gravity models. The gravity model has been successfully improved with a factor of two after applying the Chang'E-1 long-wavelength tracking data. Using the new models, some medium-scale lunar surface characteristics such as basins and volcanoes have been identified. Furthermore, the old mascon basins of Bouguer, gravity anomaly and craters have been discovered with the Chang'E-1 selenodetic data.
基金supported by the programs of Chinese Academy of Sciences for Visiting Professorship for Senior International Scientists, Hundred Talent Project(s) of Chinese Academy of Sciences, National Natural Science Foundation of China (Grant Nos.10973031 and 11043004)National High-Tech Research and Development Program of China (Grant No.2008AA12A 210)+1 种基金Pujiang Project of Shanghai (Grant No.10PJ1411700)RISE/SELENE Project of the National Astronomical Observatory of Japan
文摘Japanese lunar explorer SELENE (KAGUYA) was equipped with 14 instruments for various measurements of the Moon. Three of these instruments took geodetic measurements of the Moon. These were two sub-satellites and a laser altimeter. The main results obtained by the instruments are: (1) precise orbit determination with an accuracy of ten meters by Doppler and same-beam VLBI; (2) the first precise gravity fields on the lunar far side by 4-way Doppler measurements; (3) the first topography in latitudes higher than 86 degrees; (4) a global map of the gravity anomaly by using the global topography and the global gravity fields; (5) a global map of the lunar crustal thickness and (6) an illumination rate map in the north and south polar regions.
文摘[Objective] The paper was to understand the harms of Actias selene ningpoana Felder to plants. [Method] The larvae were cultured in five different groups: camphor tree, cherry tree, crape myrtle tree, poplar and willow, to observe the growth status of larvae. [Result] The survival rates of A. selene ningpoana in cherry tree and crape myrtle tree group were higher. The larvae in cherry tree group had faster growth, and the adults were large. [Conclusion] A. selene ningpoana is most harmful to cherry trees, which should be paid special attention in cherry garden.
基金supported by the Basic Research Project, "Development of New Geological Technology for Tracing Earth and Planetary Evolution" of the Korea Institute of Geoscience and Mineral Resources (KIGAM)
文摘A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an accuracy of - λ/4 or better, where 2 is the wavelength of the HF radar pulse at its center frequency. The performance of the proposed technique was confirmed by simulation which was carried out under the condition of design facts of the SELENE LRS mission. The highly accurate orbit positioning enables precise superposition of HF SAR images so that the inherent mirror image ambiguity problem of HF SAR imaging is resolved to obtain a quality SAR image of the HF band. In addition ambitious 2D-SAR processing would be possible when the above accuracy is available.
