Ajisai Spin Parameter Determination Using Graz Kilohertz Satellite Laser Ranging Data

The spin rate and direction of the spherical satellite Ajisai and its slowdown between October 2003 and June 2005 were determined using Graz full-rate kilohertz satellite laser ranging (SLR) data. The high density of the kilohertz data results in a precise scanning of the satellite´s retroreflector panel orientation during the spin motion. Applying spectral analysis methods, the resulting frequencies allow the identification of the arrangement of the involved laser retroreflector panels at any instant in time during the pass. Using this method, the spin rate with a high accuracy (a root mean square of 4.03times10^-4 Hz) and the slowdown of the spin rate during the investigated period with a magnitude of 0.0077497 Hz/year were calculated. These results were obtained in near real time from automatically performed analysis procedures during routine SLR tracking, i.e., day and night observations without any additional hardware