Lunar Radar Sounder
Outline of Instrument

LRS is designed for sounding the surface and subsurface structures of the Moon by using HF radar technique with the frequency of 5 MHz. The low frequency radar method makes it possible to realize the mapping of the subsurface structure within a depth of several km with a range resolution of less than 100 m for a region with a horizontal scale of several tens of km. LRS will contribute to the study of the thermal history of the lunar surface region relating to a time scale of several hundreds of millions of years.

Planetary radio waves and plasma waves around the moon's orbit will be observed without any interference from man-made noise from the earth and solar radiation.

Specifications
Mass 23.182kg
Power 56.7W
Sounder obs.
SDR frequency 5MHz (main freq.)
Radiation Power 800W
Pulse width 200 micro sec
Modulation 10kHz/micro sec
Sounding depth 5km
Natural plasma wave obs.
Frequency 10Hz - 30MHz
Telemetry speed
High speed 492kbps
Low speed 176kbps

LRS Component test @ Radiowave test facility (Tsukuba Space Center)

2004/Dec/20-22
2006/Feb/27-28
The image of the test setup (LRS-E, LRS-P, dummy-antenna and the test equipments). The image of the test setup (LRS-E, LRS-P, dummy-antenna and the test equipments).


Principle of Observation

The LRS system transmits RF pulses with frequency of 5 MHz which is able to penetrate deep into the Moon's subsurface region. When the radio waves meet with the discontinuity of subsurface material, it makes a subsurface echo signal. Observation of subsurface signal makes it possible to see subsurface structure of the Moon.

LRS uses two sets of 30m tip-to-tip long dipole antennas for the 5 MHz radar observation.
LRS uses two sets of 30m tip-to-tip long dipole antennas for the 5 MHz radar observation.


Results Expected

Example of the LRS observation over a synthesized moon's surface and subsurface structure is demonstrated in the below panel. The stratification and tectonic feature observed by the LRS system are important keys to understand evolution of the Moon.

Example of the LRS observation over a synthesized moon's surface and subsurface structure is demonstrated in the below panel.


PI Introduction
LRS Takayuki Ono

Takayuki Ono

Planetary Plasma Physics Laboratory,
Department of Geophysics,
Graduate School of Science, Tohoku Univ.