• Journal of Magnetics
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• 제20권1호
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• pp.62-68
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• 2015

This paper presents an experimental technique to accurately separate a permanent magnetic field and an induced one from the total magnetic fields generated by a steel ship, through compensating for the Earth's magnetic field. To achieve this, an Earth's magnetic field simulator was constructed at a non-magnetic laboratory, and the field separation technique was developed, which consisted of five stages. The proposed method was tested with a scaled model ship, and its permanent and induced magnetic fields were successfully extracted from the magnetic field created by the ship. Finally, based on the separated permanent magnetic field data, the permanent magnetization distribution on the hull was predicted by solving an inverse problem. Accordingly, the permanent magnetic fields generated by the ship can easily be calculated at any depth of water.

• 한국군사과학기술학회지
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• 제16권4호
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• pp.465-472
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• 2013

Since 1990, Agency for Defense Development is operating the non-magnetic laboratory for the development of key technology for the underwater magnetic stealth part, the research of the magnetic application weapons and the technical support for Korean Navy. Recently, we installed the new three-axis earth magnetic field simulator and the measurement system in the non-magnetic laboratory which is replacing the existing outdated facility. In this paper, we deal with the detailed design result of the earth magnetic field simulator and the measurement system. Also, we describe the effective method to separate the permanent and the induced magnetic field from the measured data for a scaled model ship using the earth magnetic field simulator and the measurement system.

• 한국지능시스템학회논문지
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• 제16권3호
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• pp.297-302
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• 2006

본 논문에서는 지구자계를 이용하여 3축 자계센서의 수직성분자계를 간편하게 보정할 수 있는 방법과 장치를 제안한다. 자계센서의 출력은 설치각도 및 이득오차에 의한 출력 오프셋을 포함하고 있다. 따라서 자계센서를 사용하기에 앞서 보정이 필요하다. 자계센서의 보정은 무자계 공간에서 이루어져야 하나 지구자계를 이용하면 간단하게 자계센서의 출력 오프셋을 보정할 수 있다. 그리고 보정을 위한 장치를 설계하였다. 제안하는 방법과 장치는 실험을 통하여 실용성을 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.36-40
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• 2003

The considered satellite is supposed to operate in the earth-point mode and sun-point mode in accordance with the mission requirements. The magnetic field correction is based on the orbit geometry using a set of measured magnetic field data from the three-axis-magnetometer and its algorithm excludes the earth’s magnetic field model. Moreover, the usefulness of the proposed method is investigated throughout the simulation of KOMPSAT-1.

• 한국자기학회지
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• 제12권4호
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• pp.149-153
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• 2002

지구자기장 이하의 저자기장 측정에 있어서 소형이고 소비전력이 작으면서 장기적 안정성이 요구되는 분야에 flux-gate 마그네토미터를 많이 사용하고 있다. 또한 많은 저자기장 측정분야가 지구자기장의 크기측정보다는 지자장의 변화를 측정하는 경우가 많기 때문에, 본 연구에서 측정범위가 $\pm$1,000 nT, 5pT/√Hz (at 1 Hz)인 flux-gate센서를 사용 $\pm$50000 nT인 지구자기장을 순차적 근사법으로 보상한 후 지구자기장의 변화를 고감도로 측정할 수 있는 3-축의 flux-gate 마그네토미터를 개발하였다.

• 한국지능시스템학회논문지
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• 제16권5호
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• pp.581-586
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• 2006

본 논문에서는 무인주행 차량의 자율주행에 사용되는 자계안내시스템에서 지자계를 제거하기 위한 새로운 방법으로 Ground 검출법을 제안한다. 자계안내시스템은 도로에 일정한 간격으로 자계표식을 매설하고 차량이 자계표식으로부터 떨어진 거리를 인식하여 주행하는 방법이다. 차량이 주행 중 측면이탈거리를 알기 위해서는 지자계가 제거된 자계표식의 자계만을 이용해야 한다. 그러나 자계센서는 자계를 검출할 때 자계표식의 자계와 지자계를 함께 계측한다. 지자계는 차량의 주행방향과 경사에 따라 다르게 검출되기 때문에 자계표식의 자계와 더해질 경우 측면이탈거리를 인식하는데 오차를 발생한다. 따라서 본 논문에서는 지자계를 제거하는 새로운 방법을 제안하고, 이를 검증하기 위한 실험 장치를 구성하였다. 그리고 실험을 통하여 제안한 방법의 타당성과 유용성을 입증한다.

• KIEAE Journal
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• 제5권1호
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• pp.43-49
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• 2005

People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. One of the properties of the earth is that the earth has a magnetic field associated with it- the Geomagnetic field. The geomagnetic field is produced by a combination of crustal rocks, external electric current systems that surround the earth that surround the earth and currents induced in the outer layers of the earth by magnetic field variations. Human beings have evolved with the background of magnetic field, they are accustomed to living in its presence. Geopathic stress occurs at geopathic zones where the geomagnetic field is disturbed. Geopathic zones exhibit magnetic charges. Geopathic zones are characterized by variations in geomagnetism, for the geomagnetic field is not uniform but exhibits many highly localized distortions, some random, some fairly regular. These occur in geological faults, caves and underground water channel. Many research papers and experiments of the western countries indicates that the geomagnetic field affects the people and living organism in dwellings. Therefore, it is necessary to investigate the geomagnetic field and people's response in living space. In this study the Health Hazard of geomagneic field in dwelling are studied through literature survey of related science field.

• 한국항공우주학회지
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• 제46권9호
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• pp.760-766
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• 2018

위성에 작용하는 외란으로 인해서 반작용휠에 원치 않는 모멘텀이 쌓인다. 이를 해소하기 위해서 위성의 축방향으로 설치한 세 개의 자기토커를 이용한다. 자기토커는 지구 자기장과 상호 작용하여 간접적으로 토크를 생성한다. 따라서 모멘텀 덤핑시 자기토커와 자기토커 주위에 형성되는 지구 자기장을 동시에 고려해야 한다. 높은 경사각을 가지는 저궤도 위성이 지구지향을 할 때 위성체의 피치축으로는 매우 약한 지구자기장이 형성된다. 이 경우 하나의 자기토커에 과부하가 걸려서 모멘텀 덤핑 성능이 떨어진다. 본 연구에서는 자기토커의 배치를 변경하여 지구지향자세에서 모멘텀 덤핑 성능을 향상시키는 방법에 대해서 살펴본다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.242-242
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• 2002

The Earth's magnetic field acquired from KOMPSAT-1's TAM (Three-Axis Magnetometer) between June 19th and 21st 2000 was analyzed. The TAM, one of the KOMPSAT-1's Attitude and Orbit Control Subsystems, plays an important role in determining and controlling the satellite's attitude. This also can provide new insight on the Earth's magnetic field. By transforming the satellite coordinate from ECI to ECEF, spherical coordinate of total magnetic field was achieved. These data were grouped into dusk (ascending) and dawn (descending) data sets, based on their local magnetic times. This partitioning is essential for performing 1-D WCA (Wavenumber Correlation Analysis). Also, this enhances the perception of external fields in the Kompsat-1's TAM magnetic maps that were compiled according to different local. The dusk and dawn data are processed independently and then merged to produce a total field magnetic anomaly map. To extract static and dynamic components, the 1-D and 2-D WCAs were applied to the sub-parallel neighboring tracks and dawn-dusk data sets. The static components were compared with the IGRF, the global spherical harmonic magnetic field model. The static and dynamic components were analyzed in terms of corefield, external, and crustal signals based on their origins.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.317-328
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• 2000

The solar wind contributes to the formation of unique space environment called the Earth's magnetosphere by various interactions with the Earth's magnetic field. Thus the solar-terrestrial environment affects the Earth's magnetic field, which can be observed with an instrument for the magnetic field measurement, the magnetometer usually mounted on the rocket and the satellite and based on the ground observatory. The magnetometer is a useful instrument for the spacecraft attitude control as well as the Earth's magnetic field measurements for the spacecraft purpose. In this paper, we present the preliminary design and test results of the two onboard magnetometers of KARI's (Korea Aerospace Research Institute) sounding rocket, KSR-3, which will be launched four times during the period of 2001-02. The KSR-3 magnetometers consist of the fluxgate magnetometer, MAG/AIM (Attitude Information Magnetometer) for acquiring the rocket flight attitude information, and of the search-coil magnetometer, MAG/SIM (Scientific Investigation Magnetometer) for the observation of the Earth's magnetic field fluctuations. With the MAG/AIM, the 3-axis attitude information can be acquired by the comparison of the resulting dc magnetic vector field with the IGRF (International Geomagnetic Reference Field). The Earth's magnetic field fluctuations ranging from 10 to 1,000 Hz can also be observed with the MAG/SIM measurement.