Determination of Earth's Orbital Parameters Using Doppler Measurements

Precision determinations of the parameters of Earth’s orbit around the Sun using methods based on the Doppler shift of 21-cm emissions from the galaxy and the repetition rate of pulsar J0332+5434 are reported. The observed values and statistical errors for the orbital parameters for the 21-cm observations are semi-major axis $a=1.00020\pm 0.00015\mathrm{a}\mathrm{u}$ and eccentricity $e=0.017077\pm 0.000077$. For the pulsar observations, the observed values are $a=1.000034\pm 0.000034\mathrm{a}\mathrm{u}$ and $e=0.016667\pm 0.000017$. The observations are based on a year-long campaign of daily drift-scan observations using a 12.8-m parabolic antenna and a receiver chain tuned to the 21-cm frequency band. The data used in the analysis are available for use in educational exercises in the supplementary material