scholarly journals Validation of Preliminary Results of Thermal Tropopause Derived from FY-3C GNOS Data

2019 ◽  
Vol 11 (9) ◽  
pp. 1139 ◽  
Author(s):  
Ziyan Liu ◽  
Yueqiang Sun ◽  
Weihua Bai ◽  
Junming Xia ◽  
Guangyuan Tan ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Satellite System ◽  
Research Field ◽  
Temperature Profiles ◽  
Temperature Deviation ◽  
Climate Research ◽  
Long Term Stability ◽  
Research Fields ◽  
Global Navigation Satellite

The state-of-art global navigation satellite system (GNSS) occultation sounder (GNOS) onboard the FengYun 3 series C satellite (FY-3C) has been in operation for more than five years. The accumulation of FY-3C GNOS atmospheric data makes it ready to be used in atmosphere and climate research fields. This work first introduces FY-3C GNOS into tropopause research and gives the error evaluation results of long-term FY-3C atmosphere profiles. We compare FY-3C results with Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) and radiosonde results and also present the FY-3C global seasonal tropopause patterns. The mean temperature deviation between FY-3C GNOS temperature profiles and COSMIC temperature profiles from January 2014 to December 2017 is globally less than 0.2 K, and the bias of tropopause height (TPH) and tropopause temperature (TPT) annual cycle derived from both collocated pairs are about 80–100 m and 1–2 K, respectively. Also, the correlation coefficients between FY-3C GNOS tropopause parameters and each radiosonde counterpart are generally larger than 0.9 and the corresponding regression coefficients are close to 1. Multiple climate phenomena shown in seasonal patterns coincide with results of other relevant studies. Our results demonstrate the long-term stability of FY-3C GNOS atmosphere profiles and utility of FY-3C GNOS data in the climate research field.

scholarly journals Application of the Fengyun 3 C GNSS occultation sounder for assessing the global ionospheric response to a magnetic storm event

2019 ◽  
Vol 12 (3) ◽  
pp. 1483-1493 ◽  
Author(s):  
Weihua Bai ◽  
Guojun Wang ◽  
Yueqiang Sun ◽  
Jiankui Shi ◽  
Guanglin Yang ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
Radio Occultation ◽  
Correlation Coefficients ◽  
Satellite System ◽  
Storm Event ◽  
Calibration Data ◽  
Long Term Stability ◽  
Negative Effect ◽  
Occultation Data ◽  
Global Navigation Satellite

Abstract. The rapid advancement of global navigation satellite system (GNSS) occultation technology in recent years has made it one of the most advanced space-based remote sensing technologies of the 21st century. GNSS radio occultation has many advantages, including all-weather operation, global coverage, high vertical resolution, high precision, long-term stability, and self-calibration. Data products from GNSS occultation sounding can greatly enhance ionospheric observations and contribute to space weather monitoring, forecasting, modeling, and research. In this study, GNSS occultation sounder (GNOS) results from a radio occultation sounding payload aboard the Fengyun 3 C (FY3-C) satellite were compared with ground-based ionosonde observations. Correlation coefficients for peak electron density (NmF2) derived from GNOS Global Position System (GPS) and Beidou navigation system (BDS) products with ionosonde data were higher than 0.9, and standard deviations were less than 20 %. Global ionospheric effects of the strong magnetic storm event in March 2015 were analyzed using GNOS results supported by ionosonde observations. The magnetic storm caused a significant disturbance in NmF2 level. Suppressed daytime and nighttime NmF2 levels indicated mainly negative storm conditions. In two longitude section zones of geomagnetic inclination between 40 and 80∘, the results of average NmF2 observed by GNOS and ground-based ionosondes showed the same basic trends during the geomagnetic storm and confirmed the negative effect of this storm event on the ionosphere. The analysis demonstrates the reliability of the GNSS radio occultation sounding instrument GNOS aboard the FY3-C satellite and confirms the utility of ionosphere products from GNOS for statistical and event-specific ionospheric physical analyses. Future FY3 series satellites and increasing numbers of Beidou navigation satellites will provide increasing GNOS occultation data on the ionosphere, which will contribute to ionosphere research and forecasting applications.

scholarly journals Application of Fengyun 3-C GNSS occulation sounder for assessing global ionospheric response to magnetic storm event

2016 ◽  
Author(s):  
Weihua Bai ◽  
Guojun Wang ◽  
Yueqiang Sun ◽  
Jiankui Shi ◽  
Xiangguang Meng ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
Radio Occultation ◽  
Correlation Coefficients ◽  
Satellite System ◽  
Storm Event ◽  
Calibration Data ◽  
Long Term Stability ◽  
Negative Effect ◽  
Occultation Data ◽  
Global Navigation Satellite

Abstract. The rapid advancement of global navigation satellite system (GNSS) occultation technology in recent years has made it one of the most advanced space detection technologies of the 21st century. GNSS radio occultation has many advantages, including all-weather operation, global coverage, high vertical resolution, high precision, long-term stability, and self-calibration. Data products from GNSS occultation sounding can greatly enhance ionospheric observations and contribute to space weather monitoring, forecasting, modeling, and research. In this study, GNSS occultation sounder (GNOS) results from a radio occultation sounding payload aboard the Fengyun 3-C (FY3-C) satellite were compared with ground-based ionosonde observations. Correlation coefficients for peak electron density (NmF2) derived from GNOS Global Position System (GPS) and Beidou navigation system (BDS) products with ionosonde data were higher than 0.9, and standard deviations were less than 20 %. Global ionospheric effects of the strong magnetic storm event in March 2015 were analyzed using GNOS results supported by ionosonde observations. The magnetic storm caused a significant disturbance in NmF2 and hmF2 levels. Suppressed daytime and nighttime NmF2 levels indicated mainly negative storm conditions. In the zone of geomagnetic inclination between 40–80 °, average NmF2 during the geomagnetic storm showed the same basic trends in GNOS measurements, and in observations from 17 ground-based ionosonde stations, and confirmed the negative effect of the event on the ionosphere. The analysis demonstrates the reliability of the GNSS radio occultation sounding instrument GNOS aboard the FY3-C satellite, and confirms the utility of ionosphere products from GNOS for statistical and event-specific ionospheric physical analyses. Future FY3 series satellites, and increasing numbers of Beidou navigation satellites, will provide increasing GNOS occultation data on the ionosphere, which will contribute to ionosphere research and forecasting applications.

scholarly journals Long-term stability of maxillary anterior alignment in non-extraction cases

2013 ◽  
Vol 18 (3) ◽  
pp. 46-53 ◽  
Author(s):  
Luiz Filiphe Gonçalves Canuto ◽  
Marcos Roberto de Freitas ◽  
Karina Maria Salvatore de Freitas ◽  
Rodrigo Hermont Cançado ◽  
Leniana Santos Neves
Keyword(s):  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Term Stability ◽  
Long Term Stability ◽  
Irregularity Index ◽  
Posttreatment Period ◽  
Fixed Appliances ◽  
Maxillary Incisors ◽  
Dental Cast

OBJECTIVE: The purpose of this retrospective study was to evaluate long-term stability of maxillary incisors alignment in cases submitted to non-extraction orthodontic treatment. METHODS: The sample comprised 23 patients (13 female; 10 male) at a mean initial age of 13.36 years (SD = 1.81 years), treated with fixed appliances. Dental cast measurements were obtained at three different time points (T1 - pretreatment, T2 - posttreatment and T3 - long-term posttreatment). Variables assessed in maxillary arch were Little Irregularity Index, intercanine, interpremolar and intermolar widths, arch length and perimeter. The statistical analysis was performed by one-way ANOVA and Tukey tests when necessary. Pearson' correlation coefficients were used to investigate possible associations between the evaluated variables. RESULTS: There was no significant change in most arch dimension measurements during and after treatment, however, during the long-term posttreatment period, it was observed a significant maxillary incisors crowding relapse. CONCLUSION: The maxillary incisors irregularity increased significantly (1.52 mm) during long-term posttreatment. None of the studied clinical factors demonstrated to be predictive of the maxillary crowding relapse.

scholarly journals Rail Vehicle Localization Exploiting Rail Track Georeferenced Coordinates

2015 ◽  
Vol 1 (2) ◽  
pp. 1-12
Author(s):  
António João Ferreira ◽  
José Miguel Almeida ◽  
Eduardo Silva
Keyword(s):  
Dead Reckoning ◽  
Satellite System ◽  
Vehicle Localization ◽  
Rail Vehicle ◽  
Position Errors ◽  
Railroad Tracks ◽  
Rail Vehicles ◽  
Global Navigation Satellite ◽  
Global Uncertainty

A novel dead reckoning algorithm conceived for localization of small inspection rail vehicles in Global Navigation Satellite System (GNSS) denied environments is presented. This work focus on simplifying the rail vehicle localization task, taking into account restrictions on movement imposed by the railroad tracks. Considering that dead reckoning techniques accumulate errors over time, leading to increasing global uncertainty, a method was designed to correct the estimates and also smooth trajectory errors backwards in time, through visualization of global landmarks. Results show the effectiveness of this approach in reducing long-term position errors. The current document reports real railroad experiments, featuring a specially designed non-motorized mobile modeling vehicle.

scholarly journals Comparison and Validation of the Ionospheric Climatological Morphology of FY3C/GNOS with COSMIC during the Recent Low Solar Activity Period

2019 ◽  
Vol 11 (22) ◽  
pp. 2686 ◽  
Author(s):  
Weihua Bai ◽  
Guangyuan Tan ◽  
Yueqiang Sun ◽  
Junming Xia ◽  
Cheng Cheng ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Satellite System ◽  
Weddell Sea ◽  
Activity Period ◽  
High Profile ◽  
Four Seasons ◽  
Weddell Sea Anomaly ◽  
Winter Anomaly ◽  
Global Navigation Satellite ◽  
Solar Activity Period

With the accumulation of the ionospheric radio occultation (IRO) data observed by Global Navigation Satellite System (GNSS) occultation sounder (GNOS) onboard FengYun-3C (FY3C) satellite, it is possible to use GNOS IRO data for ionospheric climatology research. Therefore, this work aims to validate the feasibility of FY3C/GNOS IRO products in climatology research by comparison with that of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), laying the foundation for its application in climatology study. Since previous verification works of FY3C/GNOS were done by comparison with ionosondes, this work matched NmF2/hmF2 of FY3C/GNOS and COSMIC into data pairs to verify the profile-level accuracy of FY3C/GNOS IRO data. The statistical results show that the overall correlation coefficients of both NmF2 and hmF2 are above 0.9, the overall bias and std of NmF2 differences between FY3C/GNOS and COSMIC are −2.19% and 17.48%, respectively, and the bias and std of hmF2 differences are −3.29 and 18.01 km, respectively, indicating a high profile-level precision consistency between FY3C/GNOS and COSMIC. In ionospheric climatology comparison, we divided NmF2/hmF2 of FY3C/GNOS into four seasons, then presented the season median NmF2/hmF2 in 5° × 10° grids and compared them with that of COSMIC. The results show that the ionospheric climatological characteristics of FY3C/GNOS and COSMIC are highly matched, both showing the typical climatological features such as equatorial ionosphere anomaly (EIA), winter anomaly, semiannual anomaly, Weddell Sea anomaly (WSA) and so on, though minor discrepancies do exist like the differences in magnitude of longitude peak structures and WSA, which verifies the reliability of FY3C/GNOS IRO products in ionospheric climatology research.

scholarly journals Combined Study of a Significant Mine Collapse Based on Seismological and Geodetic Data—29 January 2019, Rudna Mine, Poland

2020 ◽  
Vol 12 (10) ◽  
pp. 1570
Author(s):  
Maya Ilieva ◽  
Łukasz Rudziński ◽  
Kamila Pawłuszek-Filipiak ◽  
Grzegorz Lizurek ◽  
Iwona Kudłacik ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Radar Data ◽  
Satellite System ◽  
High Frequency Oscillations ◽  
System Data ◽  
Satellite Radar ◽  
Global Navigation Satellite ◽  
Mine Collapse ◽  
Mine Roof

On 29 January 2019, the collapse of a mine roof resulted in a significant surface deformation and generated a tremor with a magnitude of 4.6 in Rudna Mine, Poland. This study combines the seismological and geodetic monitoring of the event. Data from local and regional seismological networks were used to estimate the mechanism of the source and the ground motion caused by the earthquake. Global Navigation Satellite System data, collected at 10 Hz, and processed as a long-term time-series of daily coordinates solutions and short-term high frequency oscillations, are in good agreement with the seismological outputs, having detected several more tremors. The range and dynamics of the deformed surface area were monitored using satellite radar techniques for slow and fast motion detection. The radar data revealed that a 2-km2 area was affected in the six days after the collapse and that there was an increase in the post-event rate of subsidence.

scholarly journals Recovering Long-term Aerosol Optical Depth Series (1976–2012) from an Astronomical Potassium-based Resonance Scattering Spectrometer

2014 ◽  
Vol 7 (4) ◽  
pp. 4093-4121 ◽  
Author(s):  
A. Barreto ◽  
E. Cuevas ◽  
P. Pallé ◽  
P. M. Romero ◽  
F. Almansa ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Correlation Coefficients ◽  
Resonant Scattering ◽  
Resonance Scattering ◽  
Data Series ◽  
Long Term Stability ◽  
Filter Radiometer ◽  
Scattered Component

Abstract. A 37 year long-term series of monochromatic Aerosol Optical Depth (AOD) has been recovered from solar irradiance measurements performed with the solar spectrometer Mark-I, deployed at Izaña mountain since 1976. The instrument operation is based on the method of resonant scattering, which presents a long-term stability and high precision in comparison to other instruments based on interference filters. However, it has been specifically designed as a reference instrument for helioseismology, and its ability to determine AOD from transmitted and scattered monochromatic radiation at 769.9 nm inside a potassium vapor cell in the presence of a permanent magnetic field is evaluated in this paper. Particularly, the use of an exposed mirrors arrangement to collect sunlight as well as the Sun-laboratory velocity dependence of the scattered component introduces some inconveniences when we perform the instrument's calibration. We have solved this problem using a quasi-continuous Langley calibration technique and a refinement procedure to correct for calibration errors as well as for the fictitious diurnal cycle on AOD data. Our results showed that calibration errors associated to the quasi-continuous Langley technique are not dependent on aerosol load, provided aerosol concentration remains constant throughout the day, assuring the validity of this technique for those periods with relatively high aerosol content required to calibrate the scattered component. The comparative analysis between the recovered AOD dataset from Mark-I and collocated quasi-simultaneous data from Cimel AErosol RObotic NETwork (AERONET) and Precision Filter Radiometer (PFR) instruments showed an absolute mean bias ≤ 0.01 in the 11 year and 12 year comparison, respectively. High correlation coefficients between AERONET/Mark-I and PFR/Mark-I pairs confirmed a very good linear relationship between instruments, proving that recovered AOD data series from Mark-I can be used together PFR and AERONET AOD data to build a long-term AOD data series at Izaña site (1976–now), suitable for future analysis of aerosols trends and inter-annual variability. Finally, the AOD preliminary trend analysis in the 29 year period from 1984 to 2012 with Mark-I AOD revealed no significant trends. However, we detected a negative significant trend of 0.047 decade−1 during the period 1984–1993.

scholarly journals Modeling long-term volcanic deformations at the Kusatsu-Shirane and Asama volcanoes, Japan using the GNSS coordinate time series

2021 ◽  
Author(s):  
Hiroshi Munekane
Keyword(s):  
Source Parameters ◽  
Tohoku Earthquake ◽  
Oblate Spheroid ◽  
Satellite System ◽  
Deformation Source ◽  
Linear Inversion ◽  
The 2011 Tohoku Earthquake ◽  
Deep Source ◽  
Global Navigation Satellite

Abstract Long-term deformations of the Kusatsu-Shirane and Asama volcanoes in central Japan were investigated using Global Navigation Satellite System (GNSS) measurements. Large postseismic deformations caused by the 2011 Tohoku earthquake — which obscure the long-term volcanic deformations — were effectively removed by approximating the postseismic and other recent tectonic deformations in terms of quadrature of the geographical eastings/northings. Subsequently, deformation source parameters were estimated by the Markov Chain Monte-Carlo (MCMC) method and linear inversion. The deformation source of the Kusatsu-Shirane volcano was found to be a sill-like oblate spheroid located a few kilometers northwest of the Yugama crater at a depth of approximately five km, while that of Asama was also estimated to be a sill-like oblate spheroid located at the western flank of the edifice at a depth of approximately 13 km, along with the previously reported shallow east-west striking dike at a depth of approximately 1 km. It was revealed that 1) volume changes of the Kusatsu-Shirane deformation source and the shallow deformation source of Asama were correlated with the volcanic activities of the corresponding volcanoes, and 2) the Asama deep source has been steadily losing volume, which may indicate that the volcano will experience less eruptions in the near future.

scholarly journals Potential of INSAT-3D Sounder Derived Total Precipitable Water Product for Weather Forecast

2018 ◽  
Author(s):  
Shailesh Parihar ◽  
Ashim Kumar Mitra ◽  
Rajiv Bhatla
Keyword(s):  
Weather Forecasting ◽  
Correlation Coefficients ◽  
India Meteorological Department ◽  
Precipitable Water ◽  
Weather Forecast ◽  
Satellite System ◽  
Indian Region ◽  
Data Consistency ◽  
Total Precipitable Water ◽  
Global Navigation Satellite

Abstract. INSAT-3D satellite objectives to upgrade the meteorological observation, monitoring of earth surface atmosphere for weather forecasting and disaster warning. The amount of the water vapor present in atmospheric column in the form of total precipitable water (TPW) derived product from atmospheric sounding system is one such weather monitoring capability in the INSAT-3D payload. The current study is based on INSAT-3D satellite sounder derived TPW and corresponding TPW from radiosonde observations (RS) and National Oceanic and Atmospheric Administration (NOAA), N-18 and N-19 have been used to assess retrieval performances. The RS TPW from 34 India Meteorological Department (IMD) stations over the Indian region from May to September 2016 has been considered for the validation. The analysis is performed on daily, monthly, sub-divisional and overall basis over the Indian region. On daily and monthly scale against RS TPW, the root mean square error (RMSE) and correlation coefficients (CC) of INSAT-3D TPW are in and around of 8 mm and above 0.8 respectively. However, on sub-divisional and overall scale, the RMSE found to be in the range of 1 to 2 mm and CC was around 0.9 in comparison with RS and NOAA. The spatial distribution of INSAT-3D TPW with actual rainfall observation is also been investigated. In general, INSAT-3D TPW correspond well with rainfall observation however, heavy rainfall events occurs in the presence of high TPW values. Furthermore, a case study with INSAT-3D TPW and ground based Global Navigation Satellite System (GNSS) receiver network have been demonstrated. It is noticed that, INSAT-3D TPW can be considered as a precursor for mesoscale activity very well. The purpose of this study is to investigate the potential use of operational INSAT-3D sounder derived TPW to weather forecast. However, the major source of improvement in INSAT-3D TPW is mainly applying the GSICS calibration corrections (Global Space-based Inter-Calibration System) on Infra-Red (IR) sounder channels at IMDPS, New Delhi, which aims to produce corrections, ensuring the data consistency and allowing them to be used to produce globally homogeneous products for environmental monitoring. The current TPW from INSAT-3D satellite can be utilized operationally for weather purpose and it can also offer substantial opportunities for improvement in now casting studies.

scholarly journals Editorial. Permanent funding for FORMakademisk

2013 ◽  
Vol 6 (3) ◽  
Author(s):  
Janne Beate Reitan
Keyword(s):  
Design Education ◽  
Design Research ◽  
Scientific Journal ◽  
Research Field ◽  
Financial Resources ◽  
Modern Education ◽  
Research Fields ◽  
Peer Reviewers

FORMakademisk is the only scientific journal in the Nordic countries that publishes articles in both design and design education. The modern education requirement for research-based teaching also applies to higher education in design and design education, which is the primary field of research published in the journal FORMakademisk. As a relatively young field of research, a great deal of research in design and design education is published as articles rather than monographs. The journal plays an important role as a source of research-based teaching and education, and the articles are used as part of the curricula at several institutions. The purpose of FORMakademisk is to build and strengthen design and design education as a research field of its own, to enhance existing design research fields, and to strengthen design education as a field in itself.Encouragement To maintain a permanent operation of FORMakademisk it is necessary to enter into long-term economic agreements with institutions that use the journal to publish or reference literature. We therefore wish to make a statement about the long-term support to FORMakademisk with these institutions as soon as possible. We encourage all our authors, peer reviewers, readers and especially the members of the editorial board to ask their institutions to provide financial resources and long-term agreements to support FORMakademisk when a letter is being sent to institutions as soon as possible.

Sign in / Sign up

Export Citation Format

Share Document