Pioneer 10 Doppler data analysis: disentangling periodic and secular anomalies

TL;DR

This study reanalyzes Pioneer probe Doppler data, confirming a secular anomaly and identifying periodic variations related to the azimuthal angle, using an independent software approach.

Contribution

It introduces a new independent analysis method that confirms the Pioneer anomaly and characterizes its periodic variations as functions of azimuthal angles.

Findings

Confirmed the secular anomaly with an amplitude of about 0.8 nms$^{-2}$

Identified periodic variations as functions of azimuthal angle $\

Improved fit with combined secular and sinusoidal components

Abstract

This paper reports the results of an analysis of the Doppler tracking data of Pioneer probes which did show an anomalous behaviour. A software has been developed for the sake of performing a data analysis as independent as possible from that of J. Anderson et al. \citep{anderson}, using the same data set. A first output of this new analysis is a confirmation of the existence of a secular anomaly with an amplitude about 0.8 nms$^{-2}$ compatible with that reported by Anderson et al. A second output is the study of periodic variations of the anomaly, which we characterize as functions of the azimuthal angle $\varphi$ defined by the directions Sun-Earth Antenna and Sun-Pioneer. An improved fit is obtained with periodic variations written as the sum of a secular acceleration and two sinusoids of the angles $\varphi$ and $2\varphi$. The tests which have been performed for assessing the robustness of these results are presented.