Earth-satellite-Earth laser long-path absorption experiment using the Retroreflector in Space (RIS) on the Advanced Earth Observing Satellite (ADEOS)

This paper reports the results of the laser long-path absorption experiment s carried out with the Retroreflector in Space (RIS) on the Advanced Earth Observing Satellite (ADEOS). The RIS is a 0.5 m diameter single-element hol low retroreflector with a unique optical design which uses a curved mirror surface to correct velocity aberrations caused by the satellite movement. I n the RIS experiments a laser beam was transmitted from a ground station, r eflected by the RIS, and received back at the ground station. The absorptio n of the intervening atmosphere was measured in the round-trip optical path . After the launch of the ADEOS in August 1996, the optical characteristics of the RIS were tested, and it was confirmed that the RIS worked well in o rbit. The spectroscopic measurement was carried out with the single-longitu dinal-mode TEA CO2 lasers by means of the method utilizing the Doppler shif t of the reflected beam caused by the movement of the satellite. The spectr um of ozone was successfully measured in the 10 mu m region, and the measur ement of the column contents of ozone was validated with the simultaneous h eterodyne spectrometer measurement. In June 1997, however, the experiment w ith the RIS was discontinued due to the malfunction of the ADEOS solar padd le.