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 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.

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 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.

Progress in developing a storm-time ionospheric correction model

1998 ◽  
Vol 22 (6) ◽  
pp. 821-827 ◽  
Author(s):  
T.J. Fuller-Rowell ◽  
M.V. Codrescu ◽  
E. Araujo-Pradere ◽  
I. Kutiev
Keyword(s):  
Ionospheric Correction ◽  
Correction Model

ANALISIS PENGARUH EKSPOR TERHADAP PERTUMBUHAN EKONOMI INDONESIA

2017 ◽  
Vol 11 (1) ◽  
pp. 1-20
Author(s):  
Ari Mulianta Ginting
Keyword(s):  
Economic Growth ◽  
Export Performance ◽  
Descriptive Analysis ◽  
Correction Model ◽  
Administration System ◽  
Long Run ◽  
Short Run ◽  
Available Information ◽  
Increasing Trends ◽  
The Relationship

Ekspor merupakan salah satu faktor terjadinya peningkatan pertumbuhan ekonomi suatu negara, sejalan dengan hipotesis export-led growth (ELG). Penelitian ini menganalisis perkembangan ekspor dan pertumbuhan ekonomi Indonesia periode kuartal I 2001 sampai dengan kuartal IV 2015. Penelitian ini menggunakan analisis deskriptif dalam menggambarkan perkembangan pertumbuhan ekonomi serta ekspor dan analisis kuantitatif metode Error Correction Model (ECM) dalam menganalisis efek jangka panjang dan jangka pendek dari ekspor terhadap pertumbuhan ekonomi. Pada periode penelitian, data yang ada menunjukkan bahwa ekspor dan pertumbuhan ekonomi Indonesia sama-sama mengalami peningkatan. Hasil regresi ECM menunjukkan bahwa ekspor memiliki pengaruh yang positif dan signifikan secara statistik terhadap pertumbuhan ekonomi Indonesia, yang mendukung hipotesis bahwa ELG berlaku untuk Indonesia. Berdasarkan hasil penelitian ini, maka untuk mendorong pertumbuhan ekonomi Indonesia diperlukan peningkatan kinerja ekspor Indonesia. Peningkatan kinerja ekspor Indonesia dapat dilakukan dengan berbagai cara, salah satunya adalah dengan perbaikan sistem administrasi ekspor, peningkatan riset dan pengembangan produk Indonesia, peningkatan sarana dan prasarana infrastruktur, stabilitas nilai tukar dan perluasan pasar non tradisional, termasuk perbaikan struktur ekspor komoditas. Export is one of the factors behind the economic growth which is in line with the export-led growth hypotesis (ELG). This research analyzes the relationship between economic growth and export of Indonesia during first quarter of 2001 until fourth quarter of 2015. It employs descriptive analysis to describe export movement and economic growth during the study period and ECM model to analyze the long run and the short run effects of export on the economic growth. The available information indicated that, during the study period, both export and economic growth showed similar increasing trends. The result of the ECM model revealed that export had a positive and statistically significant relationship with the economic growth, supporting the hypotesis of ELG in Indonesia. Hence, to accelerate economic growth, efforts are required to boost the export performance in Indonesia. The Export performance can be increased by several way, such as improving the export administration system, increasing the research and development of Indonesian products, improving the facilities and infrastructure, exchange rate stability and the non-tradisional markets expansion, and including improvement of the export commodity structure.

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