Fig. 5.

Left panel is R _n spectrum of reference MLI lithospheric field (black) and difference between it and a “field only” derived model (red) and between it and the final “field plus gradient” derived model (blue) at Earth’s surface. Right panel is degree correlation ρ _n of “field only” (red) and “field plus gradient” (blue) coefficients with the reference model coefficients. The vertical dashed lines indicate n = 133, which is the upper degree limit for threshold accuracy requirements.