May 2022, Volume 1 Issue 3
    

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  • Review
    PING Jinsong
    2014, 1(3): 163-163.
  • Review
    Clive NEAL, PING Jinsong
    The Moon, which was believed that died out about 2.5-3.5 billion years ago with volcanic and tectonic activity had essentially ceased by 2.5 Ga., represents an end member in terms of terrestrial planet evolution in the inner Solar System. However, the Apollo data, especially coupled with the new data of the Moon about lunar tectonic, volcanic, moonquake and interior structure obtained by lunar orbiters and landers during the past dozen years, shows evidence that suggests the Moon remained active from deep interior to the surface, and by no means of died out totally. This will change our view of the lunar evolution history and status.
  • Review
    Alexander GUSEV, MENG Zhi guo, PING Jinsong, Natalia PETROVA, Hideo HANADA
    The emphasis will be put on the evidences of lunar core existence and on the necessity to take this fact into account in the lunar librations theory. Our goal is to show how the millisecond precision observations of lunar physical librations in the projects. We discuss geophysical parameters, geometrical and dynamic ellipticity of liquid core and viscose-elastic mantel of the multilayered Moon. The research results include the survey of internal structure of the Moon, tabulated values of geophysical parameters and geophysical profile of the Moon, including liquid lunar core, values of geometrical compression on the Moon’s surface, densities, as well as graphic representations of the received data. The new prospects for horizons of research and development of the Moon for the nearest decade will be opened.
  • Review
    Alexander Sergeevich KOSOV, Vladimir Michailovich GOTLIB, Vriiy Alexandrovich KOROGOD, Uriiy Alexandrovich NEMLIHER, Dmitriy Petrovich SKULACHEV
    These years, the Russia Space Agency is planning a couple of new lunar orbiting and landing explorations, the Luna-Resource and Luna-Glob Projects. Three kinds of radio scientific payloads will be installed on them: two radio beacons, installed on Luna-Resource and Luna-Glob Landers separately, and a Ka-band receiver installed on Luna-Glob orbiter. The beacons will irradiate signals at two radio frequency bands of 8.4 GHz and 32 GHz. The 8.4 GHz signals will be transmitted to the Earth, where the VLBI ground based network will be used for celestial mechanics experiments and as a navigation tool. It will be possible to measure the beacon’s positions with accuracy about 1 cm and to register Moon’s libration. The 32 GHz band will be used as a kind of orbiter navigation tool and for lunar gravity field investigation. The Ka band signal will be directed to local zenith and will be received by orbiter’s receiver. Investigation of Non-uniformity of lunar gravity field (experiment INGL) will be performed in vicinity of landing regions with accuracy 3-5 mGal. The spatial resolution will be about 20 km. The experiment is based on precise Doppler shift measurement.
  • Review
    Mikhail Vasilyevich VASILYEV, Eleonora Ivanovna YAGUDINA
    More accurate observations and ephemerides to support the space programs are required. Currently, lunar ephemerides of adequate accuracy are being developed and maintained by IAA RAS (Institute of Applied Astronomy Russian Academy of Sciences) under the name EPM-ERA. The accuracy of EPM-ERA ephemeris is still worse a little bit than that of competitive French INPOP and American DE ephemerides. The ways to improve the quality of EPM-ERA ephemeris are presented and discussed. However, EPM-ERA ephemeris is based on only measurements kindly provided by American and French LLR observatories. To overcome this problem the project of Russian LLR station was initiated by several organizations including IAA RAS. The proposed location of this station is Siberia, Altai region that promised visible improvement of existing LLR network geometry. Perspectives of the project, current problems and progress are presented and discussed. The impact on improving ephemeris of the Moon is activity of IAA RAS connected with Russian Luna-Glob and Luna-Resource programs. VLBI network "Quasar" is prepared now to observe space vehicles and lunar landers
  • Review
    PING Jinsong, WANG Mingyuan, ZHANG Sujun, JIAN Nianchuan, WANG Zhen, YAN Jianguo, MENG Qiao, CHEN Congyan, XI Yuhao, TANG Jife, ZHANG Tianyi, LI Wenxiao, ZHANG Hongbo, WANG Min
    Planetary radio science experiments have been carried out in Chinese lunar exploration missions of Chang’e-1/2/3. The astronomical VLBI technique was adopted for tracking and orbiting of the Chinese Chang’e 1 & 2 missions, and played an important role in positioning the orbit injection and hard landing. Besides the orbiters’ POD work and lander positioning work using open loop and close loop R&RR and VLBI tracking data, many other experiments have also been done. In orbiter missions, the lunar gravity field model was improved by using Chang’e-1 R&RR data, and new topographical features were discovered based on the new model. Also, the micro-wave passive method was used to study the lunar surface and sub-surface features. In extended mission of Chang’e-2, POD by R&RR and VLBI played the key role in L2 Lissajous orbit mission,and in Toutatis asteroid fly-by mission. In Chang’e-3 landing mission, a 3-way open loop lunar radio phase ranging and Doppler technique was suggested and tested. This method, called Lunar Radio Phase Ranging (LRPR) can be a new space geodetic technique to measure the station position, earth tide and rotation, lunar orbit, tide and liberation, by means of independent observation, or to work together with Lunar Laser Ranging. Also, it can be used in future Mars mission.
  • Article
    Hideo HANADA, Seiitsu TSURUTA, Kazuyoshi ASARI, Hiroshi ARAKI, Hirotomo NODA, Shingo KASHIMA, Ken-ichi FUNAZAKI, Fuyuhiko KIKUCHI, Koji MATSUMOTO, Yusuke KONO, Hiroo KUNIMORI, Sho SASAKI
    We investigated basic characteristics of the telescope for In-situ Lunar Orientation Measurement (ILOM), such as the centroid accuracy and the effects of temperature change, tilt and ground vibrations, by laboratory experiments using a Bread Board Model and by simulations. We have a prospect to observe the lunar rotation on the lunar surface with the accuracy of 1 milliarcsecond. We will make test observations on the ground in order to evaluate overall characteristics with the target accuracy of better than 0.1 arcseconds.
  • Article
    LI Wenxiao, Alexander GUSEV, PING Jinsong, ZHANG Tongji
    Based on the lunar physical parameters in ephemeris DE430/LE430 of JPL/NASA, we estimated the moments of inertia of the Moon. Using these values of moment of inertia, the frequencies and periods of lunar free librations in different modes have been calculated by solving the rotational differential equations of rigid Moon. We compared the results and discussed the analytic results of lunar librations. Meanwhile, we also estimated the forced librations by means of the amplitude of longitudinal part. For the further research, more analytic methods should be mixed into numerical results, and the interactions between two layers would be next objective.
  • Article
    ZHANG Yuanzhi, AN Lu, HUANG Zhaojun
    This paper briefly introduces the bidirectional reflectance feature of spinel based on space weathering. The distribution of the bidirectional reflectance feature of spinel under the different conditions of space weathering was simulated using the Hapke model. The results show that the absorption features at 0.6μm and 1.9μm could be used to determine the spinel when the Moon Mineralogy Mapper (M3) data is applied. However, when the Chang’e-1 Interference Imaging Spectrometer (IIM) data is used, the space weathering level should be first analyzed, and then the absorption features at 0.6μm and 0.9μm could be applied to identify the mineral. These results provide the basis of identifying spinel using absorptive positions and depths of the spinel, which can also be applied to M3 data and Chang’e-1 IIM data processing.
  • Article
    Meng Zhiguo, Ping Jinsong, Alexander Gusev, CAI Zhanchuan, Chen Si
    As Mare Orientale is the youngest and best preserved multiring impact basin on the Moon, it is of essential importance to study its composition and structure for clues to the processes and histories of older, more degraded features. In this paper, the (FeO+TiO2) abundance derived from Clementine UV-VIS data and the CELMS data from Chang’e-2 satellite are employed to study the Microwave Emission features of the Mare Orientale. The results indicate that the regions with high CELMS data and high brightness temperature difference agree well with high (FeO+TiO2) abundance both on noon and on midnight. However, the change of the area with high CELMS data and high brightness temperature difference with the frequency indicates that the composition of the lunar regolith is varied with depth. The (FeO+TiO2) abundance in Maunder Crater is low, whereas the CELMS data and the brightness temperature differences in the low frequencies and the high frequencies show distinctly different features, which indicates that the composition of the lunar regolith here in the upper layer and the lower layer may be different. The abnormal microwave emission apparently exists in the regions (10°S /106°W), (5°S /104°W) and (13°S /103°W) in highland with low (FeO+TiO2) abundance, which is likely related to the temperature gradient of the deep regolith.. The microwave emission features in these areas are of special significance to study the evolution of the Mare Orientale.
  • Article
    WANG Zhen, WANG Na, PING Jinsong
    To measure the thin plasma layer above the surface of the moon, via using radio occultation technique and coherent radio waves of the S/X-band, dual-frequency measurements could be acquired at a given Earth-based receiving station. On the line-sight direction, the terrestrial ionosphere, interplanetary plasma and thin lunar ionosphere are mixed together, in order to investigate the relatively pure variation of ionospheric total electron content (TEC) surrounding the moon. Using the trend extrapolation method, the terrestrial ionosphere and interplanetary disturbance error influence could be eliminated, so as to estimate the fitting trend component. The TEC of lunar ionosphere is obtained about ~10-14 /m2, after subtracting this trend component from the original observation data obtained at the tracking station.
  • Article
    SUN Jing, WANG Mei, PING Jinsong
    Differential VLBI (D-VLBI) is commonly used in VLBI spacecraft tracking in order to reach sufficient accuracy. Despite the simple concept of measuring a spacecraft’s angular distance to a well-known quasar, this method also holds some characteristics that are worth closer inspection. In this paper, the measurement principle is demonstrated and some basic thoughts on the observation sequence and the resultant scan gaps as well as on the separation angle between the reference source and the spacecraft are presented. This is followed by some geometrical reflections on the similarity of the transmission media. The results in this paper will provide technical support for the subsequent spacecraft mission.
  • Article
    CHEN Lue, TANG Geshi, Hu Songjie, PING Jinsong, XU Xueqing, XIA Jinchao
    This paper proposes a prediction method of UT1-UTC in Earth orientation parameters (EOP) by dual differential least-squares (LS) and autoregressive (AR) model. Firstly, leap seconds are removed in UT1-UTC observations, and Earth zonal harmonic tidal are corrected. Then, the corrected UT1-UTC are processed by dual differential method, the stationarity of polar motion parameters is improved. Then, LS+AR method is utilized to analyze the dual differential UT1-UTC to obtain the preliminary prediction results. Finally, the preliminary prediction results are processed by inverse dual differential method, and tidal correction are extrapolated and leap seconds are recovered to obtain high accuracy UT1-UTC prediction results. The prediction results are compared with EOP prediction comparison campaign (EOP_PCC) results. It shows that the short-term UT1-UTC parameters prediction error is at the same level of EOP_PCC. The one day prediction accuracy of UT1-UTC is less than 0.03ms, which is better than EOP_PCC one day UT1-UTC prediction accuracy. And, the daily routine UT1-UTC prediction in Beijing Aerospace Control Center is introduced.
  • Article
    TANG Geshi, CAO Jianfeng, HAN Songtao, Hu Songjie, REN tianpeng, CHEN lue, SUN Jing, WANG Mei, LI Yifei, LI Li
    After the successful launch on December 2, 2013, Chang’e-3 performed soft landing on lunar surface on December 14, which is designed to stand in place for more than 1 year, and it can transmit X-band signals when the transponder is switched on. With the signals, ranging, Doppler, carrier phase, VLBI delay and delay rate can be acquired from ground TT&C antennas and VLBI antennas. These techniques can be called Lunar Radio Measurement (LRM) collectively. By LRM technique, more rich observations can be acquired nearly at the same time, so it could be more effective in contributing to space geodesy than LLR(lunar Laser Ranging)which only provides ranging observation. To analyze the LRM technique, MEKAS (Moon Earth Kinematical Analysis Software) is developed, which can simulate all kinds of observations mentioned above, carry out covariance analysis and determine the parameters including CE-3 position on the lunar surface, ground site coordinates UT1, EOP and love number. Simulation results show that LRM technique has wide prospects in earth and lunar science.