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Lunar Radar Sounder (LRS) experiment on-board the SELENE spacecraft

Abstract

The Lunar Radar Sounder (LRS) experiment on-board the SELENE (SELenological and ENngineering Explorer) spacecraft has been planned for observation of the subsurface structure of the Moon, using HF radar operating in the frequency range around 5 MHz. The fundamental technique of the instrumentation of LRS is based on the plasma waves and sounder experiments which have been established through the observations of the earth’s magnetosphere, plasmasphere and ionosphere by using EXOS-B (Jikiken), EXOS-C (Ohzora) and EXOS-D (Akebono) satellites; and the plasma sounder for observations of the Martian ionosphere as well as surface land shape are installed on the Planet-B (Nozomi) spacecraft which will arrive at Mars in 2003. For the exploration of lunar subsurface structures applying the developed sounder technique, discrimination of weak subsurface echo signals from intense surface echoes is important; to solve this problem, a frequency modulation technique applied to the sounder RF pulse has been introduced to improve the resolution of range measurements. By using digital signal processing techniques for the generation of the sounder RF waveform and on-board data analyses, it becomes possible to improve the S/N ratio and resolution for the subsurface sounding of the Moon. The instrumental and theoretical studies for developing the LRS system for subsurface sounding of the Moon have shown that the LRS observations on-board the SELENE spacecraft will give detailed information about the subsurface structures within a depth of 5 km from the lunar surface, with a range resolution of less than 75 m for a region with a horizontal scale of several tens of km. This capability is evaluated to be sufficient for study of the thermal history of the lunar surface region relating to a time scale of several tens of millions of years.

References

  1. Cooper, B. L., J. L. Carter, and C. A. Sapp, New evidence for graben origin of Oceanus Procellarum from lunar sounder optical imagery, J. Geophys. Res., 99(E2), 3799–3812, 1994.

    Article  Google Scholar 

  2. Franklin, C. A. and M. A. MacLean, The design of swept-frequency topside sounders, Proc. IEEE, Vol. 57, 897–929, 1969.

    Article  Google Scholar 

  3. Harz, T. R., Radio noise levels within and above the ionosphere, Proc. IEEE, Vol. 57, 1042–1050, 1969.

    Article  Google Scholar 

  4. Jackson, J. E. and E. S. Warren, Objectives, History, and Principal achievements of the topside sounder and ISIS project, Proc. IEEE, Vol. 57, 861–865, 1969.

    Article  Google Scholar 

  5. Kobayashi, T., T. Ono, and H. Oya, Computer simulation on investigation of lunar subsurface structure by radar sounders—Studies related to the SELENE project, Earth Planets Space, 2000 (to be submitted).

  6. Obara, T. and H. Oya, Plasma condition in the polar ionosphere observed in SPW experiments of PPS system on board the Ohzora (EXOS-C) satellite, J. Geomag. Geoelectr., 37, 285–307, 1985.

    Article  Google Scholar 

  7. Olhoeft, G. R. and D. W. Strangway, Dielectric properties of the first 100 meters of the moon, Earth Planet. Sci. Lett., 24, 394–404, 1975.

    Article  Google Scholar 

  8. Ono, T., H. Oya, A. Morioka, A. Kumamoto, K. Kobayashi, T. Obara, and T. Nakagawa, Plasma Waves and Sounder (PWS) experiment onboard the Planet-B Mars orbiter, Earth Planets Space, 50, 213–221, 1998.

    Article  Google Scholar 

  9. Oya, H. and T. Ono, Stimulation of plasma waves in the magnetosphere using satellite JIKIKEN (EXOS-B), Adv. Space Res., 1, 217–220, 1981.

    Article  Google Scholar 

  10. Oya, H. and T. Ono, Stimulation of plasma waves in the magnetosphere using satellite JIKIKEN (EXOS-B) part II: Plasma density across the plasmapause, J. Geomag. Geoelectr., 39, 591–607, 1987.

    Article  Google Scholar 

  11. Oya, H. and T. Ono, A new altimeter for Mars land shape observations utilizing the ionospheric sounder system onboard the Planet-B spacecraft, Earth Planets Space, 50, 229–234, 1998.

    Article  Google Scholar 

  12. Oya, H., T. Ono, and T. Kamada, Stimulation of plasma waves in the magnetosphere using satellite JIKIKEN (EXOS-B), Part-I: Observation of plasma resonances, J. Geomag. Geoelectr., 33(1), 3–25, 1981.

    Article  Google Scholar 

  13. Oya, H., A. Morioka, K. Kobayashi, M. Iizima, T. Ono, H. Miyaoka, T. Okada, and T. Obara, Plasma wave observations and sounder experiments (PWS) on-board Akebono (EXOS-D) satellite, J. Geomag. Geoelectr., 42, 411–442, 1990.

    Article  Google Scholar 

  14. Oya, H., A. Morioka, and T. Obara, Leaked AKR and Terrestrial hectometric radiations discovered by the plasma wave and planetary plasma sounder experiments on-board the Ohzora (EXOS-C) satellite—instrumentation and observation results of plasma wave phenomena, J. Geomag. Geoelectr., 37, 237–262, 1985.

    Article  Google Scholar 

  15. Peeples, W. J., W. R. Sill, W. M. Thomas, S. H. Ward, R. J. Phillips, R. L. Jordan, E. A. Abbott, and T. J. Killpack, Orbital radar evidence for lunar subsurface layering in Maria Serenitaris and Crisium, J. Geophys. Res., 83(B7), 3459–3468, 1978.

    Article  Google Scholar 

  16. Phillips, R. J., G. F. Adams, W. E. Brown, Jr., R. E. Eggleton, P. L. Jackson, R. Jordan, W. I. Linlor, W. J. Peeples, L. J. Porcello, J. Ryu, G. Schaber, W. R. Sill, T. W. Thompson, S. H. Ward, and J. S. Zelenka, Apollo lunar sounder experiment, NASA Spec. Publ., 330(22), 1–26, 1973.

    Google Scholar 

  17. Porcello, L. J., R. L. Jordan, J. S. Zelenka, G. F. Adams, R. J. Phillips, W. E. Brown, Jr., S. H. Ward, and P. L. Jackson, The Apollo lunar sounder radar system, Proc. IEEE, Vol. 62, 769–783, 1974.

    Article  Google Scholar 

  18. Sharpton, V. L. and J. W. Head III, Stratigraphy and structural evolution of southern Mare Serenitaris: a reinterpretation based on Apollo lunar sounder experiment data, J. Geophys. Res., 8(B13), 10983–10998, 1982.

    Article  Google Scholar 

  19. Strangway, D. W. and G. R. Olhoeft, Electrical properties of planetary surfaces, Phil. Trans. R. Soc. London, A, 285, 441–450, 1977.

    Article  Google Scholar 

  20. Yamaji, A., S. Sasaki, Y. Yamaguchi, T. Ono, J. Haruyama, and T. Okada, Lunar tectonics and its implications for the origin and evolution of the moon, Mem. Geol. Soc. Japan, 50, 213–226, 1998.

    Google Scholar 

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Correspondence to Takayuki Ono.

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Now at Fukui University of Technology.

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Ono, T., Oya, H. Lunar Radar Sounder (LRS) experiment on-board the SELENE spacecraft. Earth Planet Sp 52, 629–637 (2000). https://doi.org/10.1186/BF03351671

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Keywords

  • Plasma Wave
  • Lunar Surface
  • Sound Experiment
  • Martian Ionosphere
  • Sound Receiver