Articles | Volume 8, issue 1
https://doi.org/10.5194/gi-8-21-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gi-8-21-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
30 Jan 2019
Research article |
| 30 Jan 2019
| 30 Jan 2019
The operator difference in absolute geomagnetic measurements
Yufei He
Institute of Geophysics, China Earthquake Administration, Beijing, 100081, China
Institute of Geophysics, China Earthquake Administration, Beijing, 100081, China
Jianjun Wang
Lanzhou Institute of Seismology, China Earthquake Administration, Lanzhou, 730000, China
Fuxi Yang
Earthquake Bureau of Xinjiang Province, Urumqi, 830011, China
Xijing Li
Qianling Observatory, Xi'an, 713300, China
Changjiang Xin
Lanzhou Observatory, Lanzhou, 730046, China
Wansheng Yan
Lanzhou Observatory, Lanzhou, 730046, China
Wentong Tian
Lanzhou Observatory, Lanzhou, 730046, China
Related authors
Yufei He, Xudong Zhao, Suqin Zhang, Qi Li, Fuxi Yang, Shaopeng He, and Pengkun Guo
EGUsphere, https://doi.org/10.5194/egusphere-2025-2557, https://doi.org/10.5194/egusphere-2025-2557, 2025
This preprint is open for discussion and under review for Geoscientific Instrumentation, Methods and Data Systems (GI).
Short summary
Short summary
This study establishes GNSS-based azimuth remeasurement scenarios for geomagnetic observatories, overcoming limitations of traditional astronomical methods. Five prioritized workflows address diverse field conditions. Validations at Hongshan, Quanzhou, and Yulin observatories confirm Scenario I (dual-GNSS alignment) and Scenario II (angular conversion) feasibility. Preliminary error analysis informs a deployment priority sequence, providing scalable solutions for complex environments.
Yufei He, Qi Li, Xudong Zhao, Suqin Zhang, and Fuxi Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-2406, https://doi.org/10.5194/egusphere-2025-2406, 2025
This preprint is open for discussion and under review for Geoscientific Instrumentation, Methods and Data Systems (GI).
Short summary
Short summary
This study evaluates the data quality and long-term robustness of reference fluxgate theodolites in Geomagnetic Network of China (GNC). Results show high stability in reference instruments and no drift. Operator dependent errors were identified as the primary contributor in observer data. The study highlights the critical role of comparisons. Future efforts should integrate sensors and automation technologies to minimize human errors, thereby providing a higher quality data for studies.
Xudong Zhao, Yufei He, Qi Li, and Xiaocan Liu
Geosci. Instrum. Method. Data Syst. Discuss., https://doi.org/10.5194/gi-2020-48, https://doi.org/10.5194/gi-2020-48, 2020
Preprint withdrawn
Short summary
Short summary
The daily variation amplitude of geomagnetic component Z could represent the diurnal variation strength of geomagnetic field. The ionospheric conductivity, neutral wind in ionosphere and the complicated underground electrical structures make combined action to effect the feature of the Z daily variation amplitude in China. This paper will provide the background information or reference to researchers who study the geomagnetic diurnal variation or to analyse the anomaly.
Yufei He, Xudong Zhao, Suqin Zhang, Qi Li, Fuxi Yang, Shaopeng He, and Pengkun Guo
EGUsphere, https://doi.org/10.5194/egusphere-2025-2557, https://doi.org/10.5194/egusphere-2025-2557, 2025
This preprint is open for discussion and under review for Geoscientific Instrumentation, Methods and Data Systems (GI).
Short summary
Short summary
This study establishes GNSS-based azimuth remeasurement scenarios for geomagnetic observatories, overcoming limitations of traditional astronomical methods. Five prioritized workflows address diverse field conditions. Validations at Hongshan, Quanzhou, and Yulin observatories confirm Scenario I (dual-GNSS alignment) and Scenario II (angular conversion) feasibility. Preliminary error analysis informs a deployment priority sequence, providing scalable solutions for complex environments.
Yufei He, Qi Li, Xudong Zhao, Suqin Zhang, and Fuxi Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-2406, https://doi.org/10.5194/egusphere-2025-2406, 2025
This preprint is open for discussion and under review for Geoscientific Instrumentation, Methods and Data Systems (GI).
Short summary
Short summary
This study evaluates the data quality and long-term robustness of reference fluxgate theodolites in Geomagnetic Network of China (GNC). Results show high stability in reference instruments and no drift. Operator dependent errors were identified as the primary contributor in observer data. The study highlights the critical role of comparisons. Future efforts should integrate sensors and automation technologies to minimize human errors, thereby providing a higher quality data for studies.
Xiujuan Hu, Shaopeng He, Xudong Zhao, Qin Tian, Alimjan Mamatemin, Pengkun Guo, and Guoping Chang
Geosci. Instrum. Method. Data Syst., 13, 301–308, https://doi.org/10.5194/gi-13-301-2024, https://doi.org/10.5194/gi-13-301-2024, 2024
Short summary
Short summary
Nearly 200 sets of three-axis fluxgate magnetometers are used in Chinese geomagnetic observatories, but due to their directional errors, it is necessary to study error correction methods to improve measurement accuracy. Experimental results show that correcting the Z-axis and D-axis directional errors is essential. The observation data after error correction demonstrate the clear correction effect. The measurement device used in the experiment is low in cost and easy to disseminate.
Xudong Zhao, Yufei He, Qi Li, and Xiaocan Liu
Geosci. Instrum. Method. Data Syst. Discuss., https://doi.org/10.5194/gi-2020-48, https://doi.org/10.5194/gi-2020-48, 2020
Preprint withdrawn
Short summary
Short summary
The daily variation amplitude of geomagnetic component Z could represent the diurnal variation strength of geomagnetic field. The ionospheric conductivity, neutral wind in ionosphere and the complicated underground electrical structures make combined action to effect the feature of the Z daily variation amplitude in China. This paper will provide the background information or reference to researchers who study the geomagnetic diurnal variation or to analyse the anomaly.
Related subject area
Data quality
Real-time plotting and evaluation of the data quality control from the CSIR- NGRI Magnetic observatories
Crack damage stress in fully saturated rocks: a new detection procedure
Airborne electromagnetic data levelling based on the structured variational method
Upgrade of LSA-SAF Meteosat Second Generation daily surface albedo (MDAL) retrieval algorithm incorporating aerosol correction and other improvements
Swarm Langmuir probes' data quality validation and future improvements
Evaluating methods for reconstructing large gaps in historic snow depth time series
Production of definitive data from Indonesian geomagnetic observatories
Auroral classification ergonomics and the implications for machine learning
Artifacts from manganese reduction in rock samples prepared by focused ion beam (FIB) slicing for X-ray microspectroscopy
The influence of sample geometry on the permeability of a porous sandstone
One second vector and scalar magnetic measurements at the low-latitude Choutuppal (CPL) magnetic observatory
Data quality control and tools in passive seismic experiments exemplified on the Czech broadband seismic pool MOBNET in the AlpArray collaborative project
Time-stamp correction of magnetic observatory data acquired during unavailability of time-synchronization services
Stability analysis of geomagnetic baseline data obtained at Cheongyang observatory in Korea
European UV DataBase (EUVDB) as a repository and quality analyser for solar spectral UV irradiance monitored in Sodankylä
Bed conduction impact on fiber optic distributed temperature sensing water temperature measurements
A framework for benchmarking of homogenisation algorithm performance on the global scale
New analysis software for Viking Lander meteorological data
Innovations and applications of the VERA quality control
Vengala Pavan Kumar, Nelapatla Phani Chandrasekhar, and Potharaju Sai Vijay Kumar
EGUsphere, https://doi.org/10.5194/egusphere-2025-1587, https://doi.org/10.5194/egusphere-2025-1587, 2025
Short summary
Short summary
A Python-based software was developed for real-time visualization and quality control at India’s CPL and HYB geomagnetic observatories. The tool generates plots, conducts quality checks, and computes first differences at 1s and 1min intervals with under 300s latency, aiding anomaly detection and quasi-definitive data preparation. Designed for future integration with AI/ML, this system enhances geomagnetic data accuracy and accessibility, revolutionizing research, forecasting, and visualization.
Sandra Schumacher and Werner Gräsle
Geosci. Instrum. Method. Data Syst., 14, 13–27, https://doi.org/10.5194/gi-14-13-2025, https://doi.org/10.5194/gi-14-13-2025, 2025
Short summary
Short summary
Under German law, crack damage stress must not be reached at any time during the operation or post-closure phase of a nuclear waste repository. This legal requirement can only be fulfilled if the parameter can be measured precisely. We have thus developed a new measurement technique, which overcomes the limitations of the conventional method. In combination, old and new methods offer an easy procedure to detect crack damage stress in fully saturated rocks in a fast and robust manner.
Qiong Zhang, Xin Chen, Zhonghang Ji, Fei Yan, Zhengkun Jin, and Yunqing Liu
Geosci. Instrum. Method. Data Syst., 13, 193–203, https://doi.org/10.5194/gi-13-193-2024, https://doi.org/10.5194/gi-13-193-2024, 2024
Short summary
Short summary
In an airborne survey, dynamic flight conditions cause unequal data levels, which have a serious impact on airborne geophysical data analysis and interpretation. A new technique is proposed to level geophysical data, and we confirm the reliability of the method by applying it to magnetic data and apparent conductivity data. The method can automatically extract the levelling errors without the participation of staff members or tie line control.
Daniel Juncu, Xavier Ceamanos, Isabel F. Trigo, Sandra Gomes, and Sandra C. Freitas
Geosci. Instrum. Method. Data Syst., 11, 389–412, https://doi.org/10.5194/gi-11-389-2022, https://doi.org/10.5194/gi-11-389-2022, 2022
Short summary
Short summary
MDAL is a near real-time, satellite-based surface albedo product based on the geostationary Meteosat Second Generation mission. We propose an update to the processing algorithm that generates MDAL and evaluate the results of these changes through comparison with the pre-update, currently operational MDAL product as well as reference data using different satellite-based albedo products and in situ measurements. We find that the update provides a valuable improvement.
Filomena Catapano, Stephan Buchert, Enkelejda Qamili, Thomas Nilsson, Jerome Bouffard, Christian Siemes, Igino Coco, Raffaella D'Amicis, Lars Tøffner-Clausen, Lorenzo Trenchi, Poul Erik Holmdahl Olsen, and Anja Stromme
Geosci. Instrum. Method. Data Syst., 11, 149–162, https://doi.org/10.5194/gi-11-149-2022, https://doi.org/10.5194/gi-11-149-2022, 2022
Short summary
Short summary
The quality control and validation activities performed by the Swarm data quality team reveal the good-quality LPs. The analysis demonstrated that the current baseline plasma data products are improved with respect to previous baseline. The LPs have captured the ionospheric plasma variability over more than half of a solar cycle, revealing the data quality dependence on the solar activity. The quality of the LP data will further improve promotion of their application to a broad range of studies.
Johannes Aschauer and Christoph Marty
Geosci. Instrum. Method. Data Syst., 10, 297–312, https://doi.org/10.5194/gi-10-297-2021, https://doi.org/10.5194/gi-10-297-2021, 2021
Short summary
Short summary
Methods for reconstruction of winter long data gaps in snow depth time series are compared. The methods use snow depth data from neighboring stations or calculate snow depth from temperature and precipitation data. All methods except one are able to reproduce the average snow depth and maximum snow depth in a winter reasonably well. For reconstructing the number of snow days with snow depth ≥ 1 cm, results suggest using a snow model instead of relying on data from neighboring stations.
Relly Margiono, Christopher W. Turbitt, Ciarán D. Beggan, and Kathryn A. Whaler
Geosci. Instrum. Method. Data Syst., 10, 169–182, https://doi.org/10.5194/gi-10-169-2021, https://doi.org/10.5194/gi-10-169-2021, 2021
Short summary
Short summary
We have produced a standardised high-quality set of measurements to create definitive data for four Indonesian Geomagnetic Observatories for 2010–2018. We explain the steps taken to update the existing data collection and processing protocols and suggest improvements to further enhance the quality of the magnetic time series at each observatory. The new data will fill the gap in the western Pacific region and provide input into geomagnetic field modeling and secular variation studies.
Derek McKay and Andreas Kvammen
Geosci. Instrum. Method. Data Syst., 9, 267–273, https://doi.org/10.5194/gi-9-267-2020, https://doi.org/10.5194/gi-9-267-2020, 2020
Short summary
Short summary
Researchers are making increasing use of machine learning to improve accuracy, efficiency and consistency. During such a study of the aurora, it was noted that biases or distortions had crept into the data because of the conditions (or ergonomics) of the human trainers. As using machine-learning techniques in auroral research is relatively new, it is critical that such biases are brought to the attention of the academic and citizen science communities.
Dorothea S. Macholdt, Jan-David Förster, Maren Müller, Bettina Weber, Michael Kappl, A. L. David Kilcoyne, Markus Weigand, Jan Leitner, Klaus Peter Jochum, Christopher Pöhlker, and Meinrat O. Andreae
Geosci. Instrum. Method. Data Syst., 8, 97–111, https://doi.org/10.5194/gi-8-97-2019, https://doi.org/10.5194/gi-8-97-2019, 2019
Short summary
Short summary
Focused ion beam (FIB) slicing is a widely used technique to prepare ultrathin slices for the microanalysis of geological and environmental samples. During our investigations of the manganese oxidation states in rock varnish slices, we found an FIB-related reduction of manganese(IV) to manganese(II) at the samples’ surfaces. This study characterizes the observed reduction artifacts and emphasizes that caution is needed in the analysis of transition metal oxidation states upon FIB preparation.
Michael J. Heap
Geosci. Instrum. Method. Data Syst., 8, 55–61, https://doi.org/10.5194/gi-8-55-2019, https://doi.org/10.5194/gi-8-55-2019, 2019
Short summary
Short summary
To better understand the influence of sample geometry on laboratory measurements of permeability, the permeabilities of sandstone samples with different lengths and diameters were measured. Despite the large range in length, aspect ratio, and volume, the permeabilities of the samples are near identical. This is due to a homogeneous porosity structure and the small grain/pore size with respect to the minimum tested diameter and length. More tests are now needed to help develop such guidelines.
Nelapatla Phani Chandrasekhar, Sai Vijay Kumar Potharaju, Kusumita Arora, Chandra Shakar Rao Kasuba, Leonid Rakhlin, Sergey Tymoshyn, Laszlo Merenyi, Anusha Chilukuri, Jayashree Bulusu, and Sergey Khomutov
Geosci. Instrum. Method. Data Syst., 6, 547–560, https://doi.org/10.5194/gi-6-547-2017, https://doi.org/10.5194/gi-6-547-2017, 2017
Short summary
Short summary
This work presents the progressive steps which led to the successful setup of such measurements at the new magnetic observatory in Choutuppal (CPL) of CSIR-NGRI, Hyderabad, India. Iterative tuning of the setup led to the generation of good quality data from 2016 onward. The processes of commissioning this setup in low-latitude conditions, with the aim of producing 1 s definitive data, and the characteristics of the data from this new instrument are presented here.
Luděk Vecsey, Jaroslava Plomerová, Petr Jedlička, Helena Munzarová, Vladislav Babuška, and the AlpArray working group
Geosci. Instrum. Method. Data Syst., 6, 505–521, https://doi.org/10.5194/gi-6-505-2017, https://doi.org/10.5194/gi-6-505-2017, 2017
Short summary
Short summary
This paper focuses on major issues related to data reliability and MOBNET network performance in the AlpArray seismic experiments. We present both new hardware and software tools that help to assure the high-quality standard of broadband seismic data. Special attention is paid to issues like a detection of sensor misorientation, timing problems, exchange of record components and/or their polarity reversal, sensor mass centring, or anomalous channel amplitudes due to imperfect gain.
Pierdavide Coïsson, Kader Telali, Benoit Heumez, Vincent Lesur, Xavier Lalanne, and Chang Jiang Xin
Geosci. Instrum. Method. Data Syst., 6, 311–317, https://doi.org/10.5194/gi-6-311-2017, https://doi.org/10.5194/gi-6-311-2017, 2017
Short summary
Short summary
Data loggers of magnetic observatories use GPS receivers to provide accurate time stamping of recorded data. Typical sampling rate is 1 s. A failure of the GPS receiver can result in erroneous time stamps. The observatory of Lanzhou, China, accumulated a lag of 28 s over 1 year. Using magnetic data recorded at other locations in a radius of 3000 km it was possible to estimate the diurnal lag and correct the time tamps to produce reliable 1 min averages of magnetic data.
Shakirah M. Amran, Wan-Seop Kim, Heh Ree Cho, and Po Gyu Park
Geosci. Instrum. Method. Data Syst., 6, 231–238, https://doi.org/10.5194/gi-6-231-2017, https://doi.org/10.5194/gi-6-231-2017, 2017
Short summary
Short summary
In this work, we analysed the Cheongyang geomagnetic baseline data from 2014 to 2016. We observed a step of more than 5 nT in the H and Z baseline in 2014 and 2015 due to artificial magnetic noise in the absolute hut. The baseline also shows a periodic modulation due to temperature variations in the fluxgate magnetometer hut. The quality of the baselines was improved by correcting the discontinuity in the H and Z baselines.
Anu Heikkilä, Jussi Kaurola, Kaisa Lakkala, Juha Matti Karhu, Esko Kyrö, Tapani Koskela, Ola Engelsen, Harry Slaper, and Gunther Seckmeyer
Geosci. Instrum. Method. Data Syst., 5, 333–345, https://doi.org/10.5194/gi-5-333-2016, https://doi.org/10.5194/gi-5-333-2016, 2016
Short summary
Short summary
Solar spectral UV irradiance data measured by the Brewer #037 spectroradiometer in Sodankylä, Finland, in 1990–2014 were examined for their quality flags given by the quality assurance (QA) tools of the European UV DataBase (EUVDB). Statistical analysis on the flags was performed, and five cases were investigated in detail. The results can be used in further development of the quality control/QA tools and selection of cases of exceptional atmospheric conditions for process studies.
T. O'Donnell Meininger and J. S. Selker
Geosci. Instrum. Method. Data Syst., 4, 19–22, https://doi.org/10.5194/gi-4-19-2015, https://doi.org/10.5194/gi-4-19-2015, 2015
K. Willett, C. Williams, I. T. Jolliffe, R. Lund, L. V. Alexander, S. Brönnimann, L. A. Vincent, S. Easterbrook, V. K. C. Venema, D. Berry, R. E. Warren, G. Lopardo, R. Auchmann, E. Aguilar, M. J. Menne, C. Gallagher, Z. Hausfather, T. Thorarinsdottir, and P. W. Thorne
Geosci. Instrum. Method. Data Syst., 3, 187–200, https://doi.org/10.5194/gi-3-187-2014, https://doi.org/10.5194/gi-3-187-2014, 2014
O. Kemppinen, J. E. Tillman, W. Schmidt, and A.-M. Harri
Geosci. Instrum. Method. Data Syst., 2, 61–69, https://doi.org/10.5194/gi-2-61-2013, https://doi.org/10.5194/gi-2-61-2013, 2013
D. Mayer, A. Steiner, and R. Steinacker
Geosci. Instrum. Method. Data Syst., 1, 135–149, https://doi.org/10.5194/gi-1-135-2012, https://doi.org/10.5194/gi-1-135-2012, 2012
Cited articles
Auster, H. U. and Auster, V.: A new method for performing an absolute
measurement of the geomagnetic field, Meas. Sci. Technol., 14, 1013,
https://doi.org/10.1088/0957-0233/14/7/315, 2003.
Bitterly, J. J., Cantin, M., Schlich, R., Folques, J., and Gilbert D.:
Portable magnetometer theodolite with fluxgate sensor for earth's magnetic
field component measurements, Geophys. Surv., 6, 233–239,
https://doi.org/10.1088/0957-0233/14/7/315, 1984.
Brunke, H.-P. and Matzka, J.: Numerical evaluation of magnetic absolute
measurements with arbitrarily distributed DI-fluxgate theodolite
orientations, Geosci. Instrum. Method. Data Syst., 7, 1–9,
https://doi.org/10.5194/gi-7-1-2018, 2018.
Deng, N., Yang, D. M., Yang, Y. F., and Chen, J.: On problems of absolute
measurement in geomagnetic observatory, J. Geodesy, 30, 129–134,
https://doi.org/10.3969/j.issn.1671-5942.2010.z1.029, 2010.
Gonsette, A., Rasson, J., and Humbled, F.: In situ vector calibration of
magnetic observatories, Geosci. Instrum. Method. Data Syst., 6, 361–366,
https://doi.org/10.5194/gi-6-361-2017, 2017a.
Gonsette, A., Rasson, J., Bracke, S., Poncelet, A., Hendrickx, O., and
Humbled, F.: Fog-based automatic true north detection for absolute magnetic
declination measurement, Geosci. Instrum. Method. Data Syst., 6, 439–446,
https://doi.org/10.5194/gi-6-439-2017, 2017b.
Hegymegi, L., Szöllősy, J., Hegymegi, C., and Domján, Á.:
Measurement experiences with FluxSet digital D/I station, Geosci. Instrum.
Method. Data Syst., 6, 279–284, https://doi.org/10.5194/gi-6-279-2017, 2017.
Jankowski, J. and Sucksdorff, C.: Absolute magnetic measurement, in: Guide
for magnetic measurements and observatory practice, IAGA V–8, Boulder, USA,
87–102, 1996.
Li, X. J., Yang, D. M., Zhang, S. Q., and He, Y. F.: The necessary of the
manual observation in absolute observation, Seismol. Geomag. Obser. Res., 33,
201–205, https://doi.org/10.3969/j.issn.1003-3246.2012.03/04.037, 2012.
Newitt, L. R., Barton, C. E., and Bitterly J.: Setting up Equipment and
Taking Measurements, in: Guide for magnetic repeat station surveys, IAGA
V–8, Boulder, USA, 43–45, 1996.
Rasson, J. L. and Gonsette, A.: The Mark II Automatic Diflux, Data Sci. J.,
10, IAGA169–IAGA173, https://doi.org/10.2481/dsj.IAGA-24, 2011.
St-Louis, B.: INTERMAGNET technical reference manual, version 4.5,
INTERMAGNET c/o British Geological Survey, available at:
http://www.intermagnet.org/publications/im_manual.pdf, last access: 17
July 2018.
Zhang, S. Q. and Yang, D. M.: Study on the stability and accuracy of baseline
values measured during the calibrating time intervals, Data Sci. J., 10,
IAGA19–IAGA24, https://doi.org/10.2481/dsj.IAGA-04, 2011.
Zhang, S. Q., Fu, C. H., He, Y. F., Yang, D. M., Li, Q., Zhao, X. D., and
Wang, J. J.: Quality control of observation data by the Geomagnetic Network
of China, Data Sci. J., 15, 1–12, https://doi.org/10.5334/dsj-2016-015, 2016.
