TY - JOUR
T1 - Lunar potassium distribution
T2 - Results from Chang'E-1 gamma ray spectrometer
AU - Zhu, Meng Hua
AU - Ma, Tao
AU - Chang, Jin
AU - Tang, Zesheng
AU - Ip, Wing Huen
AU - Xu, Aoao
N1 - Funding Information:
The authors would like to thank all the staff of Chang’E-1 mission for their outstanding work and generous helps. ZHU MengHua is grateful to R. C. REEDY (LPI, USA), O. FONI, C. d’USTON (CESR, France), N. HASEBE (Waseda Univ., Japan), W. Z. FA (IPGP, France), and L. Y. ZHANG (NAOC, China) for many thoughtful discussions and suggestions. Financial supports from the Science and Technology of Development Fund of Macau (Grant Nos. 004/2011/A1, 003/2008/A1 and 042/2007/A3) are also gratefully acknowledged.
PY - 2011/11
Y1 - 2011/11
N2 - The global map of potassium is represented in this paper from Chang'E-1 (CE-1) Gamma-ray Spectrometer (CGRS) for its one-year mission. Assuming a linear relationship between net count rate and its abundance, the average potassium abundance of individual landing sites is used as ground-truth for the calibration to derive the global map of absolute concentration. Although CGRS spectra have a lower signal-to-noise ratio, the translated map still keeps relative variations. As calculated from Apollo, Lunar Prospector, and Kaguya, global potassium map from CGRS shows high concentrations on the lunar nearside and secondary concentrations located in the South Pole-Aitken (SPA) basin on the farside. The comparison with Lunar Prospector potassium map shows a good correlation, though abundances on the highlands of the farside are much lower than that of Lunar Prospector. Since the footprint of CGRS measurements is larger than the sampling radius of each landing site, the calibrated map shows a larger variation range of the scale than that of Lunar Prospector, which was derived using theoretical calculation; namely, the calibrated map has higher values in the areas with high concentration while having lower values for the areas with lower concentration. However, the derived potassium map is more consistent with the lunar sample data than that of Lunar Prospector.
AB - The global map of potassium is represented in this paper from Chang'E-1 (CE-1) Gamma-ray Spectrometer (CGRS) for its one-year mission. Assuming a linear relationship between net count rate and its abundance, the average potassium abundance of individual landing sites is used as ground-truth for the calibration to derive the global map of absolute concentration. Although CGRS spectra have a lower signal-to-noise ratio, the translated map still keeps relative variations. As calculated from Apollo, Lunar Prospector, and Kaguya, global potassium map from CGRS shows high concentrations on the lunar nearside and secondary concentrations located in the South Pole-Aitken (SPA) basin on the farside. The comparison with Lunar Prospector potassium map shows a good correlation, though abundances on the highlands of the farside are much lower than that of Lunar Prospector. Since the footprint of CGRS measurements is larger than the sampling radius of each landing site, the calibrated map shows a larger variation range of the scale than that of Lunar Prospector, which was derived using theoretical calculation; namely, the calibrated map has higher values in the areas with high concentration while having lower values for the areas with lower concentration. However, the derived potassium map is more consistent with the lunar sample data than that of Lunar Prospector.
KW - Chang'E-1
KW - empirical calibration
KW - gamma-ray spectrometer
KW - potassium distribution
UR - http://www.scopus.com/inward/record.url?scp=82355175849&partnerID=8YFLogxK
U2 - 10.1007/s11433-011-4491-x
DO - 10.1007/s11433-011-4491-x
M3 - 期刊論文
AN - SCOPUS:82355175849
SN - 1674-7348
VL - 54
SP - 2083
EP - 2090
JO - Science China: Physics, Mechanics and Astronomy
JF - Science China: Physics, Mechanics and Astronomy
IS - 11
ER -