Resolution No.27 (1963): Recommendations for satellite measurements for the WMS

The IUGG recommends that measurements of the total magnetic force for the WMS from satellites below 1000km altitude be conducted in such a manner that the absolute accuracy of measurement at each point is within 10 gammas without application of corrections for instrument drifts or satellite generated fields, and that the date and universal time of each measurement be specified to permit removal of time variations in the final analysis of survey measurements, and recommends particularly:

1. that magnetometers of the nuclear or atomic resonance type be used,
2. that the latitude, longitude, and altitude coordinates of each measurement be known and specified to an accuracy of 1000m in the horizontal plane and 250m in the vertical direction, and
3. that the magnetic field of the satellite be such that its contribution to the field at the magnetometer sensor be small and consistent with the absolute accuracy specified above.