Degree-wise spectra of RMS quantities σ_n, δ_n, and Δ_n for several specified cases. Top panels: plot the strong-field dynamo category (m₀ = 2), and bottom three panels: weak-field dynamo category (m₀ = 9). The panel columns are permuted from left to right in ascending order of the convective strength . In the curve legends, each subscript labels a respective mission simulation schedule. 6013 denotes the 60° orbital inclination angle, 1000 km altitude, and three-month tracking time. 8913 denotes the 89° orbital inclination angle, 1000 km altitude, and three-month tracking time. 8933 also denotes the 89° orbital inclination angle, 3000 km altitude, and three-month tracking time. The label “FM” is the abbreviation for “forward model”, which means that σ_n is computed from and . Here Δ_n is always calculated between mission solutions and the given gravitational field models, as given in Tables 1–3.