Earth radius
where "ω"E is the angular frequency of the Earth, "R"E is the Earth radius, and "φ"i and "φ"o are the inbound and outbound equatorial angles of the spacecraft. This formula was derived later by Jean Paul Mbelek from special relativity, leading to one of the possible explanations of the effect. This does not, however, consider the SSN residuals – see "Possible explanations" below.