Development of an Optimized Hybrid Magnetometer for Earth’s Magnetic Field Studies
Abstract
The design of hybrid magnetometers is typically a nonlinear multi-objective optimization problem. Sometimes, an optimal magnetometer performance is difficult to achieve due to low sensitivity sensors which decrease with an increase in noise level while trying to reduce the sensor dimension. Moreover, these approaches are too difficult, slow, time consuming, expensive, and do not produce optimal magnetometer performance. As a result, little attempt has been made to develop hybrid magnetometer sensor. Thus far, no existing magnetometer device has incorporated two sensors, combined in a single unit device that can measure earth's magnetic ?elds in three co-ordinates direction simultaneously. This observed situation prompted the development of a locally made hybrid magnetometer device that can determine magnetic field in 3-dimensional X, Y and Z coordinates variation of the earth and total magnetic field. The developed magnetometer device consisted HMC5883 and proton precession sensors combined in a single unit that determined magnetic field of X, Y and Z axis simultaneously. The data logger was wired and hand-assembled utilizing a factory-built-in HMC5883 and Proton Procession sensors combined with Arduino Uno328 micro-controller, which contains ADC, real time clock, data storage, voltage regulator (ICLM7805) and kerosene. The device detects the X, Y and Z co- ordinates of the magnetic field in analog form. The data were digitized using analog-to-digital- converter (ADC) which were processed by micro-controller and later displayed through liquid crystal display (LCD) screen. The data were also automatically saved in an SD card in Excel format. The measurements variations of the earth residual magnetic field were taken spatially, giving a minimum value of 363.1172nT for the magneto resistive magnetometer, 357.205nT for proton precession magnetometer and 361.708nT for the geometric smart magnetometer; and giving a maximum value of
