Calibrating 15 years of GOLF data

TL;DR

This paper discusses the calibration of 15 years of GOLF solar data to correct for instrumental aging and thermal effects, enabling precise analysis of low-frequency solar oscillations.

Contribution

It introduces a calibration process for long-term GOLF data to improve the accuracy of solar oscillation measurements.

Findings

Calibration reduces instrumental bias over 15 years

Enhanced data quality for low-frequency oscillation analysis

Preparation for studying solar core dynamics

Abstract

The GOLF resonant scattering spectrophotometer aboard SoHO has now provided 15 years of continuous high precision Sun-as-a-star radial-velocity measurements. This length of time series provides very high resolution in the frequency domain and is combined with very good long-term instrumental stability. These are the requirements for measuring the low-l low-frequency global oscillations of the Sun that will unlock the secrets of the solar core. However, before the scientifically interesting gravity and mixed modes of oscillation fully reveal themselves, a correction and calibration of the whole data set is required. Here we present work towards producing a 15 year GOLF data set corrected for instrumental ageing and thermal variation.