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Lunar Radar Sounder (LRS)

NSSDCA ID: 2007-039A-06

Mission Name: Kaguya
Principal Investigator:Dr. Takayuki Ono


The Lunar Radar Sounder (LRS) is a ground penetrating radar designed to investigate the geologic subsurface structure of the Moon to a few km depth. The radar is an FM/CW system transmitting in the High-Frequency (HF) band at a center frequency of 5 MHz and a swept frequency range of 2 MHz. A swept frequency signal pulse with a width of 200 microseconds is synthesized using a waveform memory and high-speed digital to analog converter and fed to a frequency amplifier to increase the power to 800 W. The pulse is transmitted through a set of two 12 m (30 m tip to tip) dipole antennas extending from opposite sides of the spacecraft. Returns from the ground are received by a second set of dipole antennas, identical but oriented orthogonally to the first set. The pulse will penetrate to several km below the lunar surface and the received echoes will have a range resolution of about 75 m. The pulses are repeated every 50 milliseconds at a sweep rate of 10 kHz/millesecond. LRS will also be used to detect plasma waves and solar and planetary radio waves from 10 Hz to 30 MHz.

Alternate Names

  • Kaguya/LRS
  • LRS

Facts in Brief

Mass: 24 kg
Power (avg): 50 W

Funding Agency

  • Japan Aerospace Exploration Agency (Japan)


  • Planetary Science: Geology and Geophysics

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Prof. Hiroshi OyaGeneral
Dr. Takayuki OnoPrincipal InvestigatorUniversity of

Selected References

  • Ono, T., and H. Oya, Lunar Radar Sounder (LRS) experiment on-board the SELENE spacecraft, Earth Planets Space, 52, 629-637, 2000.
  • Kobayashi, T., et al., A-scope analysis of subsurface radar sounding of lunar mare region, Earth Planets Space, 54, No. 10, 973-982, 2002.
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