Estimation of overbound on ionospheric spatial decorrelation over low‐latitude region for ground‐based augmentation systems
| Autor: | Sarma Dattatreya Achanta, Supraja Reddy Ammana |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
020301 aerospace & aeronautics
010504 meteorology & atmospheric sciences Total electron content GNSS augmentation business.industry Gaussian 02 engineering and technology Geodesy Residual 01 natural sciences Physics::Geophysics symbols.namesake 0203 mechanical engineering Local Area Augmentation System Physics::Space Physics Global Positioning System symbols Electrical and Electronic Engineering Ionosphere business Decorrelation Geology 0105 earth and related environmental sciences Remote sensing |
| Zdroj: | IET Radar, Sonar & Navigation. 10:637-645 |
| ISSN: | 1751-8792 |
| DOI: | 10.1049/iet-rsn.2015.0469 |
| Popis: | In ground-based augmentation systems (GBAS), such as local area augmentation system (LAAS) of USA, variation of ionospheric delay between LAAS ground facility and the user leads to residual ionospheric error. Hence, the users need to compute the bounds on residual ionospheric error with the help of a parameter, σ vertical_ionospheric_gradient (σ vig). As σ vig is a function of geographic region, the estimated value of σ vig for mid-latitude regions (4 mm/km) is not appropriate for low-latitude regions where ionosphere is highly varying and is characterised by large spatial gradients. In this study, gradients are computed with processed total electron content data from 16 stations of global positioning system aided geo augmented navigation network and using the time-step method. The distribution of gradients is compared with one-sigma Gaussian distribution to obtain ‘inflation factor’. σ vig overbound is computed for several days data comprising of quiet, moderate and storm conditions of ionosphere using the corresponding inflation factors. It is found that overbound values of 4.5 and 14.4 mm/km are required to bind the gradients under quiet and active conditions. These findings are useful for designing a safe and reliable GBAS for low-latitude stations. |
| Databáze: | OpenAIRE |
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