TRAC (Fluxgate Magnetometer)

This experiment used a triaxial fluxgate magnetometer primarily intended for spacecraft attitude determination and control, plus extra electronics needed to give magnetic field measurements of sufficient sensitivity and accuracy to study fields associated with field aligned currents. Normal spacecraft systems produced 8-bit magnetic field measurements, corresponding to +/- 200 nT precision. Special electronics (the TRAC system) produced a 12-bit measurement every 43-sec, plus 8-bit digitizations for the differences between N magnetic vectors/sec and the immediately preceding 43-sec digitized value. N ranged between 0.4 and 100 for the four available memory (ZAP) modes. Full magnetic vectors at full time resolution were reconstructed during ground data processing. With this approach, both the time resolution and precision (+/- 5 nT) of the data enable study of field-aligned current phenomena. Useful data were produced for the full life of the spacecraft (1981-1986). See Berthelier et al, Ann. Geophys., 38, 635, 1982, for further details.

本实验主要采用了一款三轴霍尔效应磁力计，该磁力计主要用于航天器姿态确定与控制，并配备了额外的电子设备以提供足够灵敏度和准确度的磁场测量，旨在研究与场向电流相关的磁场。常规的航天器系统产生了8位磁场的测量值，对应于±200纳特精度。特殊的电子设备（TRAC系统）每隔43秒产生一个12位的测量值，并附加了8位数字化的N磁场向量/秒与紧接前43秒数字化值的差值。N值在四个可用的存储（ZAP）模式中介于0.4至100之间。在地面数据处理过程中，全时间分辨率的完整磁场向量得以重建。采用此方法，数据的时间分辨率和精度（±5纳特）使得研究场向电流现象成为可能。在航天器整个使用寿命（1981-1986年）内，产生了有价值的观测数据。详见Berthelier等人在《Ann. Geophys.》，38卷，第635页，1982年的详细报道。