Time Empirical Ionospheric Correction Model (STORM) response in IRI2000 and challenges for empirical modeling in the future

Radio Science ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
E. A. Araujo-Pradere ◽  
T. J. Fuller-Rowell ◽  
D. Bilitza
Keyword(s):  
Empirical Modeling ◽  
Ionospheric Correction ◽  
Correction Model ◽  
Storm Response ◽  
The Future

scholarly journals STORM: An empirical storm-time ionospheric correction model 2. Validation

Radio Science ◽  
2002 ◽  
Vol 37 (5) ◽  
pp. 4-1-4-14 ◽  
Author(s):  
E. A. Araujo-Pradere ◽  
T. J. Fuller-Rowell
Keyword(s):  
Ionospheric Correction ◽  
Correction Model

scholarly journals Assessment and Comparison of Broadcast Ionospheric Models: NTCM-BC, BDGIM, and Klobuchar

2020 ◽  
Vol 12 (7) ◽  
pp. 1215 ◽  
Author(s):  
Chao Yang ◽  
Jing Guo ◽  
Tao Geng ◽  
Qile Zhao ◽  
Kecai Jiang ◽  
...  
Keyword(s):  
Ionospheric Delay ◽  
Global Navigation Satellite Systems ◽  
Single Frequency ◽  
Electron Content ◽  
Ionospheric Correction ◽  
Total Electron ◽  
Correction Model ◽  
Satellite Systems ◽  
Satellite Navigation System ◽  
Navigation Data

For single-frequency Global Navigation Satellite Systems (GNSSs) users, ionospheric delay is the main error source affecting the accuracy of positioning. Applying a broadcast ionospheric correction model to mitigate the ionospheric delay is essential for meter-to-decimeter-level accuracy positioning. To provide support for real-time single-frequency operations, particularly in the China area, we assessed the performance of three broadcast ionospheric correction models, namely, the Neustrelitz total electron content (TEC) broadcast model (NTCM-BC), the BeiDou global broadcast ionospheric delay correction model (BDGIM), and the Klobuchar model. In this study, the broadcast coefficients of Klobuchar and BDGIM are obtained from the navigation data files directly. Two sets of coefficients of NTCM-BC for China and global areas are estimated. The slant total electron contents (STEC) data from more than 80 validation stations and the final vertical TEC (VTEC) data of the Center for Orbit Determination in Europe (CODE) are used as independent benchmarks for comparison. Compared to GPS STEC during the period of Day of Year (DOY) 101~199, 2019, the ionospheric correction ratio of NTCM-BC, BDGIM, and Klobuchar are 79.4%, 64.9%, and 57.7% in China, respectively. For the global area, the root-mean-square (RMS) errors of these three models are 3.67 TECU (1 TECU = 1016 electrons/m2), 5.48 TECU, and 8.92 TECU, respectively. Compared to CODE VTEC in the same period, NTCM-BC, BDGIM, and Klobuchar can correct 72.6%, 69.8%, and 61.7% of ionospheric delay, respectively. Hence, NTCM-BC is recommended for use as the broadcast ionospheric model for the new-generation BeiDou satellite navigation system (BDS) and its satellite-based augmentation system.

Assessment of future flood intensification in Central Vietnam using a super-high-resolution climate model output

2013 ◽  
Vol 4 (4) ◽  
pp. 373-389 ◽  
Author(s):  
Do Hoai Nam ◽  
Keiko Udo ◽  
Akira Mano
Keyword(s):  
High Resolution ◽  
Bias Correction ◽  
Climate Model ◽  
Global Climate Model ◽  
Annual Rainfall ◽  
Model Output ◽  
Correction Model ◽  
Central Vietnam ◽  
The Future ◽  
Climate Model Output

This paper presents an assessment of the changes in future floods. The ranked area-average heavy daily rainfall amounts simulated by a super-high-resolution (20 km mesh) global climate model output are corrected with consideration of the effects of the topography on heavy rainfall patterns and used as a basis to model design storm hyetographs. The rainfall data are then used as the input for a nearly calibration-free parameter rainfall–runoff model to simulate floods in the future climate (2075–2099) at the Upper Thu Bon River basin in Central Vietnam. The results show that although the future mean annual rainfall will not be considerably different compared to the present-day climate (1979–2003), extreme rainfall is projected to increase vigorously, leading to a similar order of intensification of future floods. It is very likely that the flood peak with a 25-year recurrence will increase approximately 42% relative to the present-day climate. The occurrence of floods with a 10-year recurrence may exceed those with a 25-year recurrence in the present-day climate. The projection results also exhibit insignificant uncertainties caused by an artificial neural network-based bias correction model. Additionally, the presented bias correction model shows advantages over a simple climatology scaling method.

scholarly journals Model formation of future teachers readiness to innovative activity

2020 ◽  
Vol 9 (29) ◽  
pp. 22-28
Author(s):  
Elmira Sh. Bekirova ◽  
Meliya N. Harabadjah ◽  
Juliya V. Makarenko ◽  
Olga I. Vaganova ◽  
Ludmila A. Sundeeva
Keyword(s):  
Higher Education ◽  
Professional Training ◽  
Innovative Activity ◽  
Empirical Modeling ◽  
Formation Model ◽  
Future Teachers ◽  
Modeling Methods ◽  
The Future ◽  
Pedagogical Competence ◽  
Model Formation

The relevance of the study is justified by the new requirements for the personality of a specialist in the field of education. Thus, an obligatory component of professional and pedagogical competence is the innovative competence of the teacher. The formation of this competence in future teachers in the system of their professional training in higher education requires special methodological system of innovative competence formation. The purpose of this article is to reveal the essence and to describe the model of readiness to innovative activity of future teachers. The purpose of the article is realized by applying theoretical (spectral analysis, generalization) and empirical (modeling, methods of pedagogical diagnostics) methods of scientific knowledge in the research. On the basis of the application of these methods in the study, the essence, features and structure of pedagogical innovative activity are determined. The necessity of innovative activity readiness formation of future teachers is substantiated. The components of the structure of teacher's readiness for innovative activity are described. The essence of pedagogical formation model of future teachers readiness to innovative activity is described. Its efficiency on the basis of quantitative and qualitative results is proved. The elements of scientific novelty in the work are represented by the creation of an experimental pedagogical model of the formation of the future teachers’ readiness to innovative activity, the substantiation of methodological and methodical aspects of its implementation, the development of the criteria base for determining the level of formation of the future teachers’ readiness to innovative activity.

scholarly journals Impact of Approximate Implementation manner in Klobuchar Model

2021 ◽  
Vol 64 (4) ◽  
pp. RS440
Author(s):  
Aghyas Aljuneidi ◽  
Hala Tawfek Hasan
Keyword(s):  
Single Frequency ◽  
Gps Receiver ◽  
Reference Field ◽  
International Geomagnetic Reference Field ◽  
Ionospheric Correction ◽  
Correction Model ◽  
Klobuchar Model ◽  
Magnetic Model ◽  
Implementation In Matlab ◽  
Made In

This paper focuses on the approximations that John A. Klobuchar made in mid 70s in his famous algorithm of ionospheric correction model for single frequency GPS receiver. At that time Klobuchar used a system of fixed geomagnetic north pole coordinates which are not accurate nowadays according to the International Geomagnetic Reference Field and to the World Magnetic Model because the geomagnetic poles move slowly. In addition, Klobuchar had to do other trigonometry simplifications in his implementation to avoid sophisticated computations. In order to evaluate this approximate implementation in a single frequency GPS receiver, ionospheric time and range delay are estimated on the entire day of January 1st 2010, using a different implementation in MATLAB. The required GPS data is obtained from recorded RINEX files at UDMC near DAMASCUS, SYRIA. In this comparative study, we reformulated the standard equations of Klobuchar model and examined the influence of its approximations on the ionospheric range delay and found a non- negligible bias in order of ten centimeters, whereas the influence of the movement of the geomagnetic poles was in order of few centimeters.

scholarly journals STORM: An empirical storm-time ionospheric correction model 1. Model description

Radio Science ◽  
2002 ◽  
Vol 37 (5) ◽  
pp. 3-1-3-12 ◽  
Author(s):  
E. A. Araujo-Pradere ◽  
T. J. Fuller-Rowell ◽  
M. V. Codrescu
Keyword(s):  
Model Description ◽  
Ionospheric Correction ◽  
Correction Model

scholarly journals A local ionospheric model for forecasting the critical frequency of the F2 layer during disturbed geomagnetic and ionospheric conditions

2008 ◽  
Vol 26 (2) ◽  
pp. 323-334 ◽  
Author(s):  
M. Pietrella ◽  
L. Perrone
Keyword(s):  
Critical Frequency ◽  
Geomagnetic Storms ◽  
Ionospheric Disturbance ◽  
Storm Events ◽  
Quiet Time ◽  
Short Term ◽  
Ionospheric Correction ◽  
Correction Model ◽  
Significant Regression ◽  
Geomagnetic Planetary Index

Abstract. An ionospheric forecasting empirical local model over Rome (IFELMOR) has been developed to predict the state of the critical frequency of the F2 layer (foF2) during geomagnetic storms and disturbed ionospheric conditions. Hourly measurements of foF2 obtained at the Rome observatory, hourly quiet-time values of foF2 (foF2QT), and the hourly time-weighted accumulation series derived from the geomagnetic planetary index ap (ap(τ)), were considered during the period January 1976–December 2003. Under the assumption that the ionospheric disturbance index log(foF2/foF2QT) is correlated to the integrated geomagnetic index ap(τ), statistically significant regression coefficients are obtained for different months and for different ranges of ap(τ) and used as input to calculate the short-term ionospheric forecasting of foF2. The empirical storm-time ionospheric correction model (STORM) was used to make comparisons with the IFELMOR model. A few comparisons between STORM's performance, IFELMOR's performance, the median measurements and the foF2QT values, were made for significant geomagnetic storm events (ap>150) occurring from 2000 to 2003. The results provided by IFELMOR are satisfactory, in particular, for periods characterized by high geomagnetic activity and very disturbed ionospheric conditions.

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