"Reply to A comment on A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model, by I. Ciufolini et al."

TL;DR

This paper defends a 2016 experimental test of Earth's frame-dragging effect using satellites, refuting claims of larger systematic errors and inaccuracies made in a 2017 comment paper.

Contribution

It provides a detailed rebuttal to incorrect claims about the error analysis and methodology of the original frame-dragging measurement.

Findings

The claimed systematic errors due to Earth's gravity harmonics are significantly overestimated in the comment.

The original measurement's precision and methodology are validated against the criticisms.

The claims about digit precision and non-repeatability are addressed and corrected.

Abstract

In 2016, we published "A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model. Measurement of Earth's dragging of inertial frames [1]", a measurement of frame-dragging, a fundamental prediction of Einstein's theory of General Relativity, using the laser-ranged satellites LARES, LAGEOS and LAGEOS 2. The formal error, or precision, of our test was about 0.2% of frame-dragging, whereas the systematic error was estimated to be about 5%. In the 2017 paper "A comment on "A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model by I. Ciufolini et al." "by L. Iorio [2] (called I2017 in the following), it was incorrectly claimed that, when comparing different Earth gravity field models, the systematic error in our test due to the Earth's even zonal harmonics of degree 6, 8, 10 could be aslarge as 15%, 6% and 36%, respectively. Furthermore, I2017 contains other, also incorrect, claims about the number of necessary significant decimal digits of the coefficients used in our test (claimed to be nine), in order to eliminate the largest uncertainties in the even zonals of degree 2 and 4, and about the non-repeatability of our test. Here we analyze and rebut those claims in I2017.