LALT is one of the instruments on board KAGUYA main orbiter for laser ranging from the satellite to the surface of the Moon in the nadir direction. LALT is able to obtain the range data globally along satellite's trajectory on the polar orbit. These range data of LALT will enable us for the first time in the world to construct a global, accurate and precise topographic map of the Moon.
|Dimensions||306 x 450 x 408 (LALT-TR)
301 x 241 x 88 (LALT-E)
|Laser output Energy||100mJ|
|Pulse repetition rate||1Hz|
LALT transmits laser pulses to the Moon from the main orbiter and measures precisely round trip times of returned signals from the Moon.
Distances between the orbiter and lunar surface are obtained as follows,
(distances) = (light speed) x (round trip times of laser signals) / 2.
The round trip time of 0.666 milliseconds corresponds to the range of 100 km.
Mission objectives of LALT are as follows;
Footprints by LALT around Copernicus crater
(diameter is about 90km) after one year mission period.
RISE (Research In Selenodesy) Project,
National Astronomical Observatory of Japan