ATS-6 UCLA Fluxgate Magnetometer

A summary of the design of the University of California at Los Angeles´ fluxgate magnetometer is presented. Instrument noise in the bandwidth 0.001 to 1.0 Hz is of order 85 my. The DC field of the spacecraft transverse to the Earth-pointing axis is Sx = 1.0 ±2.1¿, SY = -2.4 ± 1.3¿. The spacecraft field parallel to this axis is less than 5¿. The small spacecraft field has made possible studies of the macroscopic field not previously possible at synchronous orbit. At the 96° west longitude of Applications Technology Satellite-6 (ATS-6), the Earth´s field is typically inclined 300 to the dipole axis at local noon. Most perturbations of the field are due to substorms. These consist of a rotation in the meridian to a more radial field followed by a subsequent rotation back. The rotation back is normally accompanied by transient variations in the azimuthal field. The exact timing of these perturbations is a function of satellite location and the details of substorm development.