A 2015 International Geomagnetic Reference Field (IGRF) candidate model based on Swarm’s experimental absolute magnetometer vector mode data

Earth, Planets and Space

Table 1 Number N of data points and Huber-weighted mean and rms misfits (in nT) for the ASM-V, VFM, and N-VFM parent models

Residual statistics of parent models
		N	ASM-V		VFM		N-VFM
		N	mean	rms	mean	rms	mean	rms
Alpha + Bravo	F _P	49,214	−0.27	4.81	+0.00	4.80	−0.01	4.80
Alpha + Bravo	F _NP + B _B	223,627	+0.04	2.30	+0.02	2.27	+0.01	2.27
	B _r	139,292	−0.02	2.45	−0.06	1.76	−0.02	1.83
	B _θ	139,292	−0.03	3.56	+0.06	3.18	+0.06	3.17
	B _ϕ	139,292	−0.16	2.96	−0.13	2.61	−0.15	2.60
Alpha	F _P	24,294	−0.31	4.94	−0.05	4.93	−0.06	4.93
	F _NP + B _B	107,329	+0.08	2.32	−0.03	2.29	+0.06	2.29
	B _r	65,169	+0.00	2.47	−0.05	1.77	+0.01	1.83
	B _θ	65,169	−0.13	3.61	+0.14	3.19	+0.04	3.19
	B _ϕ	65,169	−0.19	3.02	−0.15	2.62	−0.17	2.61
Bravo	F _P	24,920	−0.23	4.68	+0.05	4.67	+0.04	4.67
	F _NP + B _B	116,298	−0.01	2.28	+0.06	2.26	−0.03	2.25
	B _r	74,123	−0.04	2.44	−0.07	1.74	−0.05	1.83
	B _θ	74,123	+0.06	3.51	−0.01	3.18	+0.08	3.16
	B _ϕ	74,123	−0.14	2.91	−0.12	2.60	−0.14	2.60

F _P refers to scalar data with (absolute) quasi-dipole latitude larger than 55° (recall that no vector data are selected at such latitudes); F _NP refers to scalar data at other latitudes (selected whenever vector data are not selected); B _B refers to the vector component along the main field direction; B _r, B _θ, and B _ϕ refer to the geocentric components