<title>Optical characteristics of the Retroreflector in Space (RIS) on the ADEOS satellite</title>

Abstract

This paper reports the optical characteristics of the Retroreflector in Space (RIS) on the advanced earth observing satellite (ADEOS) in orbit. The RIS is a 0.5 m diameter single-element hollow cube-corner retroreflector with a unique design which uses a curved mirror to correct the velocity aberration caused by the satellite movement. We used a Nd:YAG laser to test the efficiency of the reflection at 532 nm. The ADEOS was actively tracked with a 1.5 m diameter tracking telescope using the image of the RIS lit by the Nd:YAG laser. We measured the intensity of return light with an image-intensified CCD camera on the guiding telescope with a diameter of 20 cm. The intensity of the return was quantified by comparing it with images of stars. We compared the result with the theoretical reflectance of the RIS, and confirmed that the reflectance of the RIS agreed with the designed value. The return from the RIS was comparable to a stellar magnitude of 2 to 3, depending on the elevation angle when lit by a 0.3 W laser with a beam divergence of 0.5 mrad.