The most common equipment used for attitude determination in small satellites are magnetometers. However, using magnetometers gives rise to many challenges. One of these challenges is the calibration of the magnetometer. Magnetometer calibration takes many factors into account. There are external and internal factors. External factors can be the satellite itself. Satellites are built of many complex subsystems. These subsystems can produce magnetic disturbances and affect the measurements taken by the magnetometer ,which also affects the attitude determination of the satellite. Internal factors are nonorthogonalityand scale factors. In this project, we aim to test different calibration methods and compare the results. Another objective is to provide a complete procedure for a calibration of the magnetometer using the Helmholtz coils. The comparison of the results with other methods can help with the decision of which should be used to calibrate the magnetometer onboard the satellite for future calibrations for MIST satellites. / En av de mest vanliga verktyg för attitydbestämning i små satteliter är magnetometer, men att använda magnetometer kan leda till många utmaningar, en av de kalibrering av magnetometern. Magnetometer kalibrering är beroende av många faktorer. Det finns inre och yttre faktorer. Yttre faktorer kan vara själva satelliten. Del system som bildar satelliten kan påverka mätningar i magnetometern och då påverkar attitydbestämning av hela satelliten. Inre faktorer är icke ortogonalitet och skalära faktorer. I det här projektet vi ska testa olika kalibrerings metoder och jämföra resultaten. Ett annat mål är att bygga en komplett procedur för att kalibrera magnetometer med hjälp av Helmholtz spolar. Jämförelsen och resultaten från kalibreringen visar hur det är möjligt att kalibrnetometer som är integrerad i satelliten för kommande kalibreringar i MIST. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

Made available in DSpace on 2016-12-12T17:38:33Z (GMT). No. of bitstreams: 1 Jean Ricardo Rusczak.pdf: 3380545 bytes, checksum: 67ba7b9893e46c6952c79403622eacb2 (MD5) Previous issue date: 2013-06-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper presents the study and development of a system for measuring magnetic field through search coils. The system consists of a magnetic shield, two Helmholtz coils to generate a magnetic field, inductive interchangeable sensors and a set of electronic boards which were used to evaluate the efficiency of the whole assembly by amplifying the sinals generated by the sensors and with a data acquisition system with LabVIEW. Several designs were developed in order to achieve the project objectives of B measures the range nT in a frequency range of 10 Hz to 10 kHz. Two types of input amplifiers were studied, one being based on the output voltage of the coils and another based on the magnetic flux passing through the coil. The instrumentation amplifier has a gain of 357,500 V / V and the transimpedance amplifier configuration has a gain of 47 000 V/I. The frequency performance is achieved in the range between 100 Hz to 10 kHz where is possible to estimate fields estimated 1 nT. The work includes the study of different materials for magnetic cores to allow miniaturization of the sensors. / Este trabalho apresenta o estudo e desenvolvimento de um sistema de medição de campo magnético através de ponteiras indutivas. O sistema é composto por uma blindagem magnética, duas bobinas de Helmholtz para a geração de campo magnético, sensores indutivos intercambiáveis e um conjunto de placas eletrônicas que serviram para avaliar a eficiência de toda a montagem ao amplificar os sinais e fazer a aquisição de dados com interface em LabVIEW. Foram desenvolvidas diversas formas construtivas a fim de se atingir os objetivos de projeto medidas na faixa de nT entre 10 Hz e 10 kHz. Dois tipos de amplificadores de entrada foram estudados, um sendo baseado na tensão de saída das espiras e outro no fluxo que passa pelas espiras. O amplificador de instrumentação possui um ganho de 357500 V/V e a configuração de fluxo possui um ganho 47000 I/V. A resposta em frequência apresentou uma performance aceitável entre 100Hz e 10 kHz onde possibilitou a leitura de campos estimados de 1 nT. Foram estudados, também, diferentes materiais para núcleos e que permitem a miniaturização dos sensores.

This thesis deals with measurement method pulsed quantities of electromagnetic field. This thesis was focused on methods, which make use of optic effect. Specially Faraday effect, Pockels effect and magneto-optic Kerr effect. Next it was focused on method makes use of Rogowski coil. At the end was shortly noticed about method makes use of calorimetric sensor. For experimentally realized has been chosen Faraday Magneto-optic Effect. In optic laboratory has been realized absolute methods and different methods making use of Wollaston polarizer on pneumatic optical desk. The main advantage of this method is the capability to measure the high frequency and high current signals. Next in this thesis has been written theory about Rogowski coil. This method has been experimentally realized in laboratory.

This thesis describes the issue of PN junction of photovoltaic cells, photovoltaic effect physics, basic materials used in photovoltaic and their properties, important for the area of photovoltaic. It deals with the problems of magnetism focused on electromagnetic fields. Experimental facility for measuring the influence of magnetic field on the solar cells through the Helmholtz coils was constructed. This work also dealing with the influence of magnetic radiation on photovoltaic cells and the influence of electromagnetic waves on the volt-ampere characteristics of the photovoltaic cell.

This Master’s thesis contains an overview of determining measurement uncertainties of direct and indirect measurements. It describes a way of creating a magnetic field with the help of Helmholtz coil and a more detailed description of some principles of magnetic field sensors. This thesis also contains a description of the experiments and the factors influencing them. The last part deals with the quantification of uncertainties from measured experiments and with the discussion of the results from these measurements.