Love’s number of the earth derived from satellite observations

Abstract

From periodic variations of the orbital inclinations of three artificial satellites 1959Alpha 1, 1960Iota 2, and 1962Beta Mu 1 Love’s number of the earth and time lag of the bodily tide due to the friction are determined, respectively,0.29±0.03 and(10±5) minutes in time.

While the previous paper on the determination of Love’s number of the earth (Kozai, 1967) was in press, a minor error was discovered in the Differential Orbit Improvement program(DOI) of the Smithsonian Astrophysical Observatory(SAO). Since the analysis was based on time-variations of the orbital inclinations which were derived by theDOI from precisely reduced Baker-Nunn observations, it is likely that the results in the previous paper was affected by the error in theDOI. Therefore, the analysis is iterated by using the revisedDOI. Three satellites, 1959Alpha 1 (Vanguard 2), 1960Iota 2 (rocket ofEcho 1), and 1962Beta Mu 1 (Anna) (see Table 1) are adopted for determining Love’s number in the present paper. The satellite, 1959Eta, which was used in the previous paper, is not adopted here, since the inclination of this satellite shows irregular variations unexplained. Instead of 1959Eta 1962Beta Mu 1 is adopted as orbital elements from precisely reduced Baker-Nunn observations have become available for a long interval of time for this satellite.