Review of the distribution of granite using geomagnetic methods at Bukit Nunggal Air Mesu Village, Pangkalan Baru Sub-District, Bangka Tengah District

Exploration is activities happens before the mining activity. It has purposes to know, predict and obtain the dimension in quality and quantity from a reserve that has economic value. From surveying at bukit Nunggal, Mesu Village, Pangkalan Baru Sub-district, Bangka Tengah District showed that there are outcrops indicating the potential for becoming a reserve for granite. Measurement is conducted to know the resource estimation and it is done by an approach of geomagnetic method that is environment friendly. Geomagnetic is passive method to measure the magnetism level or susceptibility from the measuring point. The total of the line to know the dispersion pattern and the depth of the resource is 13 lines with the space between measurement is 10m. From the geomagnetic measurement obtained IGRF value is 42969, inclined degree 0.424 declined degree – 21.157, susceptibility value in between -54.2nT to 56.1 nT, and the granite susceptibility value is in between 21 nT to 50nT. The anomalies map showed that there is a resource potential, and the dispersion is from east to west. Viewed from the topography and the residential areas, mining activity is recommended to be done in the west area.

The operator difference in absolute geomagnetic measurements

Absolute geomagnetic measurement is very important at geomagnetic observatories. It plays a decisive role in data quality control and instrument calibration. As absolute geomagnetic measurements from modern fluxgate theodolite instruments have high precision, usually within 1 arcsec, the measurement results are susceptible to external factors. The operator difference is one of these factors and has become an important consideration that can not be ignored with respect to measurement results. Therefore, an experiment was designed in order to estimate the operator difference. Six fluxgate theodolites were used and six observers who were proficient in absolute measurements were invited to participate. The observers took turns making absolute geomagnetic measurements, and the operator difference between the observers for each instrument was computed by comparing baseline values using statistical methods.

The personal difference in absolute geomagnetic measurements

Absolute geomagnetic measurement is very important work in geomagnetic observatories. It plays a decisive role in data quality control and instrument calibration. As modern fluxgate theodolite in absolute geomagnetic measurements has a high precision, usually with 1 second of arc, the measurement results are susceptible to external factors. The personal difference is one of these factors, and it has become an important factor that cannot be ignored in measurement results. In order to estimate the personal difference, an experiment has been designed. Six fluxgate theodolites were used and six observers who were proficient in absolute measurements were invited to this experiment. Then observers made the absolute geomagnetic measurements in turns, and the personal difference among the observers for each instrument was computed by comparing baseline values. Finally, the personal difference can be estimated by a statistical method.

Geomagnetic Gradient Bionic Navigation Based on Parallel Approach Method

Priori geomagnetic information is important to the geomagnetic navigation. However in practice, the precision of the geomagnetic information is a greatly constraint to the development of the geomagnetic navigation. In order to solve this problem, this paper present a geomagnetic gradient bionic navigation method based on parallel approach without any priori information. Inspired by the evidence that many creatures can navigate using the Earth magnetic field, the navigation process can be considered as a convergence of multi-objective problem, and develop the bionics navigation model. By introducing the parallel approach method to the navigation process, the heading angle can be estimated with the information of magnetic field gradient. The simulation results show the proposed method is able to navigation effectively without magnetic priori information, just rely on the actual geomagnetic measurement, which has implies potential application in the future.

Recursive of Least Square Based Online Calibration Method in Geomagnetic Detection

With the problem of attitude measurement accuracy is susceptible to various errors of geomagnetic survey, this paper establishes geomagnetic measurement error ellipsoid model by analysis of on the environment and own errors, uses the maximum likelihood algorithm for solving the static error correction coefficient. The experimental results show that, the maximum of attitude angle errors is less than 5° near blind direction, online combination correction can ensure the accuracy of attitude detection system under different shooting conditions.