Magnetic anomaly component data measured by Magsat is compared with synthetic anomaly component fields arising from an equivalent source dipole array at the Earth's surface generated from total anomaly data alone. It is found that the synthesis components fit the component data regardless of the dipole orientation assigned to the equivalent sources and of the dipole spacing. Tentative conclusions are 1) over the U.S., vector anomaly fields can be determined to the accuracy of the measurements from the total field anomaly data alone, and 2) the equivalent source technique is not useful for determining the direction of large-scale crustal magnetization.