Assessment of performance of the SHAO-C tropospheric delay correction model over low latitude and complex topography

Yohannes Getachew Ejigu, Gizaw Mengistu Tsidu

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    Tropospheric signal delay can introduce a considerable error in satellite positioning if it is not properly modeled. In this work, the spatial and temporal variations of the zenith tropospheric delay (ZTD) over low latitude and complex topography of Ethiopia and Eritrea from the Greater Horn of Africa (GHA) region, are analyzed using ECMWF (European Center for Medium-Range Weather Forecast) pressure-level atmospheric data and compared with ZTD over 5-year period from 2007-2011 measured at several GPS stations of UNAVCO in the region. A new tropospheric delay correction model, SHAO-C used in China, is evaluated for its performance over the region with most GPS observational stations located in Ethiopia. The ZTD along altitude, latitude and longitude is fitted with a second order polynomials at a reference height, and the mean ZTD is modeled directly by a harmonic function together with an initial value and an amplitude in each grid. The coefficients of this model are generated using the ERA-Interim data at moderate resolution. The altitude is obtained from high resolution digital elevation model (DEM). The agreement between GPS and model ZTD is found to be very good which is reflected in overall average bias between -4.3 to -1.0 cm, and RMSE less than 4.5 cm. The results are within the requirements of most GNSS navigation or positioning applications in terms of the tropospheric delay correction.

    Original languageEnglish
    Title of host publicationProceedings of 2016 International Conference on Localization and GNSS, ICL-GNSS 2016
    PublisherInstitute of Electrical and Electronics Engineers Inc.
    ISBN (Electronic)9781509017577
    DOIs
    Publication statusPublished - Aug 4 2016
    Event2016 International Conference on Localization and GNSS, ICL-GNSS 2016 - Barcelona, Spain
    Duration: Jun 28 2016Jun 30 2016

    Other

    Other2016 International Conference on Localization and GNSS, ICL-GNSS 2016
    CountrySpain
    CityBarcelona
    Period6/28/166/30/16

    Fingerprint

    Topography
    Global positioning system
    Harmonic functions
    Model
    Positioning
    Navigation
    Polynomials
    Satellites
    Longitude
    Digital Elevation Model
    Harmonic Functions
    Weather
    Forecast
    China
    High Resolution
    Grid
    Polynomial
    Requirements
    Coefficient
    Range of data

    All Science Journal Classification (ASJC) codes

    • Computer Networks and Communications
    • Control and Optimization
    • Signal Processing

    Cite this

    Ejigu, Y. G., & Tsidu, G. M. (2016). Assessment of performance of the SHAO-C tropospheric delay correction model over low latitude and complex topography. In Proceedings of 2016 International Conference on Localization and GNSS, ICL-GNSS 2016 [7533860] Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ICL-GNSS.2016.7533860
    Ejigu, Yohannes Getachew ; Tsidu, Gizaw Mengistu. / Assessment of performance of the SHAO-C tropospheric delay correction model over low latitude and complex topography. Proceedings of 2016 International Conference on Localization and GNSS, ICL-GNSS 2016. Institute of Electrical and Electronics Engineers Inc., 2016.
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    abstract = "Tropospheric signal delay can introduce a considerable error in satellite positioning if it is not properly modeled. In this work, the spatial and temporal variations of the zenith tropospheric delay (ZTD) over low latitude and complex topography of Ethiopia and Eritrea from the Greater Horn of Africa (GHA) region, are analyzed using ECMWF (European Center for Medium-Range Weather Forecast) pressure-level atmospheric data and compared with ZTD over 5-year period from 2007-2011 measured at several GPS stations of UNAVCO in the region. A new tropospheric delay correction model, SHAO-C used in China, is evaluated for its performance over the region with most GPS observational stations located in Ethiopia. The ZTD along altitude, latitude and longitude is fitted with a second order polynomials at a reference height, and the mean ZTD is modeled directly by a harmonic function together with an initial value and an amplitude in each grid. The coefficients of this model are generated using the ERA-Interim data at moderate resolution. The altitude is obtained from high resolution digital elevation model (DEM). The agreement between GPS and model ZTD is found to be very good which is reflected in overall average bias between -4.3 to -1.0 cm, and RMSE less than 4.5 cm. The results are within the requirements of most GNSS navigation or positioning applications in terms of the tropospheric delay correction.",
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    Ejigu, YG & Tsidu, GM 2016, Assessment of performance of the SHAO-C tropospheric delay correction model over low latitude and complex topography. in Proceedings of 2016 International Conference on Localization and GNSS, ICL-GNSS 2016., 7533860, Institute of Electrical and Electronics Engineers Inc., 2016 International Conference on Localization and GNSS, ICL-GNSS 2016, Barcelona, Spain, 6/28/16. https://doi.org/10.1109/ICL-GNSS.2016.7533860

    Assessment of performance of the SHAO-C tropospheric delay correction model over low latitude and complex topography. / Ejigu, Yohannes Getachew; Tsidu, Gizaw Mengistu.

    Proceedings of 2016 International Conference on Localization and GNSS, ICL-GNSS 2016. Institute of Electrical and Electronics Engineers Inc., 2016. 7533860.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

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    Ejigu YG, Tsidu GM. Assessment of performance of the SHAO-C tropospheric delay correction model over low latitude and complex topography. In Proceedings of 2016 International Conference on Localization and GNSS, ICL-GNSS 2016. Institute of Electrical and Electronics Engineers Inc. 2016. 7533860 https://doi.org/10.1109/ICL-GNSS.2016.7533860