We can consider that its effect is the same for the measurement of each
magnetometer in the array, shown in Figure 1.
For the scheme of attitude estimation combining low cost MEMSIMU,
magnetometer with single antenna GPS, Strapedown Inertial Navigation system (SINS) of MEMS gyroscope, and accelerometer could provide angles utilizing the differential equation for quaternion vector but suffer from accumulating errors induced by gyroscopes bias drift.
Despite the fact, that Xsens MTi-G supports specialized
magnetometer auto-calibration procedure, ellipsoid fitting algorithm was used to calibrate
magnetometer.
Such calibration of the instrument in terms of the response under the influence of a magnetic field and different temperatures as well as in the different orientations of the
magnetometer respect to the surface has been described in Diaz Michelena et al.
For he heading calculation,
magnetometer measurements need to be normalized by applying calibration parameters and then by tilt compensation.
GPS and
magnetometer provide strong observability of pe spacecraft orbital states because GPS could measure directly pe spacecraft position vector and pe
magnetometer measurements are also functions of spacecraft position.
For the purposes of magnetic field detection, three-axis digital low power
magnetometer (MAG) MAG3110 from Freescale was used.
The standard deviations of gyro, accelerometer, and
magnetometer were set to 0.6 deg/s, 0.0981 m/[s.sup.2], and 4.8 mGauss.
The generic configuration of an optical Mx
magnetometer is shown in Figure 1.
While a
magnetometer usually is more stable and not susceptible to all of the same errors, it, too, has characteristics operators are wise to understand.
Figure 2 shows the
magnetometer results for July 14, recording a quiet day until 18:00.
I-Prober 520 is a general-purpose H-field probe based on the fluxgate
magnetometer principle; it allows track currents to be measured over a dynamic range from 10 mA to 20 A (pk-pk) with a bandwidth of DC to 5 MHz.
