Atmospheric water vapour degrades the accuracy of the results of space geodetic observations due to permanent electric dipole moments. It creates excess path lengths by retarding (slowing and bending) the propagation of the electromagnetic waves that are used in global positioning system (GPS) and very long baseline interferometry (VLBI) observations. It is known that the excess path lengths are less than 30~40 cm at the most, and are the primary obstacles of space geodesy because of the highly variable distribution of water vapour in the atmosphere. In this study, we compared modern five wet mapping functions by evaluating their effects on the tropospheric signal delay and position estimates in GPS data processing, and precise Egypt wet mapping function model is derived based on eight stations of radiosonde data well-distributed over and around Egypt (five stations used to estimate new model and other three as check points). To derive the new Egypt wet mapping function, the troposphere is divided into regular small layers. Ray tracing technique of actual signal path traveled in the troposphere is used to estimate tropospheric slant delay. Real GPS data of five stations (RTK-Network methods) were used for the assessment of new model against the available international models. These international models include Niell (NMF), Black & Eisner (B&EMF), Ifidas (IFMF), Hearing (HMF), and UNBabc MF. The data were processed using Bernese software version 5.0. The results indicate that the new Egypt wet MF model is the best model at Egypt region and has improved the wet tropospheric delay estimation up to 23.3 percent at five degree elevation angles.
Published in | American Journal of Remote Sensing (Volume 6, Issue 1) |
DOI | 10.11648/j.ajrs.20180601.16 |
Page(s) | 29-38 |
Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
Copyright |
Copyright © The Author(s), 2018. Published by Science Publishing Group |
Radiosonde Data, Troposphere Models, GPS Data, Egyptian Meteorological Authority (EMA), Wet Mapping Function
[1] | Zarzoura F., R. Ehigiator and B. Mazurov, (2013). “Accuracy Improvement of GNSS and Real Time Kinematic Using Egyptian Network as a Case Study”, Computer Engineering and Intelligent Systems, ISSN 2222-1719 (Paper) ISSN 2222-2863 (Online), Vol.4, No.12, 2013. |
[2] | Sudhir Man Shrestha, (2003). “Investigations into the Estimation of Tropospheric Delay and Wet Refractivity Using GPS Measurements”, Department of Geomatics Engineering, University of Calgary, Alberta, Canada, July, 2003. |
[3] | Mendes V. B. and R. B. Langely., (1994), “A comprehensive Analysis of Mapping Functions Used in Modeling Tropospheric Propagation Delay in Space Geodetic Data”. Geodetic Research Laboratory, Department of Geodesy and Geomatics Engineering, University of New Brunswick. |
[4] | Marini, J. W., 1972. “Correction of Satellite Tracking Data for an Arbitrary Tropospheric Profile”. Radio Science, Vol. 7, No. 2, pp. 223-231. |
[5] | Chao, C. C., 1972. “A model for Tropospheric Calibration from Daily Surface and Radiosonde Balloon Measurements”. JPL Technical Memorandum 391-350, Jet Propulsion Laboratory, Pasadena, CA. |
[6] | Davis, J, L., Herring, T, A., Shapiro, I, I., Rogers, A, E, E., and Elgered, G., 1985. “Geodesy by Radio Interferometry: Effects of Atmospheric Modeling Errors on Estimates of Baseline Length”. Radio Science, Vol. 20, No. 6, pp. 1593-1607, Nov.-Dec, 1985. |
[7] | Ifadis, I. M., 1986. The Atmospheric Delay of Radio Waves: Modeling the Elevation Dependence on a Global Scale. School of Electrical and Computer Engineering, Chalmers University of Technology, Goteborg, Sweden, Technical Report No. 38L, pp. 115. |
[8] | Herring, T. A., 1992. Modeling Atmospheric Delays in the Analysis of Space Geodetic Data. Proceedings of the Symposium on Refraction of Trans-Atmospheric Signals in Geodesy, Eds. J. C. De Munck and T. A. Th. Spoelstra, Netherlands Geodetic Commission, Publications on Geodesy, No. 36, pp. 157-164. |
[9] | Niell, A. E., 1996. “Global Mapping Functions for the Atmosphere Delay at Radio Wavelengths”. Journal of Geophysical Research, Vol. 101, No. B2, pp. 3227-3246. |
[10] | Guo J., and Richard B. L., (2003). “A New Tropospheric Propagation Delay Mapping Function for Elevation Angles Down to 2. Department of Geodesy and Geomatics Engineering, University of New Brunswick, Canada. |
[11] | Black, H. D. and A. Eisner, 1984. “Correcting Satellite Doppler Data for Tropospheric Effects”. Journal of Geophysical Research, Vol. 89, No. D2, pp. 2616-2626. |
[12] | Langely, R, B., and Guo, J., 2003. A New Tropospheric Propagation Delay Mapping Function for Elevation Angles to 2°". Proceeding of ION GPS/GNSS 2003, 16th International Technical Meeting of the satellite Division of the Institute of Navigation, Portland, OR, 9-12 sep., 2003, pp 386-396. |
[13] | Abdelfatah, M. A., Mousa, A. E., Salama, I. M. and El-Fiky, G. S., 2009. “Assessment of tropospheric delay models in GPS baseline data analysis: a case study of a regional network at upper Egypt”. J. Civil Eng. Res. Mag. AL-Azhar Univ. 31 (4), 1143–1156. |
[14] | Kleijer, F., (2004). “Troposphere Modeling and Filtering for Precise GPS Leveling”. Department of Mathematical Geodesy and Positioning, Faculty of Aerospace Engineering, Delft University of Technology, Netherlands. |
[15] | Younes, S. A., 2016. “Modeling Investigation of Wet Tropospheric Delay Error and Precipitable Water Vapor Content in Egypt”. Egypt, J. Remote Sensing Space Sci. (2016), http://dx.doi.org/10.1016/j.ejrs.2016.05.002. |
[16] | Thayer, G. D., (1974), “An Improved Equation for the Radio Refractive Index of Air”, Radio Science, Vol. 9. No. 10, pp. 803-807. |
[17] | Younes S. A., (2014), “Improved dry tropospheric propagation delay mapping function for GPS measurements in Egypt". Journal of Spatial Science, 2014 Vol. 59, No. 2, 181–190. |
APA Style
Sobhy Abd Elmonam Younes. (2018). Study the Effect of New Egypt Wet Mapping Function on Space Geodetic Measurements. American Journal of Remote Sensing, 6(1), 29-38. https://doi.org/10.11648/j.ajrs.20180601.16
ACS Style
Sobhy Abd Elmonam Younes. Study the Effect of New Egypt Wet Mapping Function on Space Geodetic Measurements. Am. J. Remote Sens. 2018, 6(1), 29-38. doi: 10.11648/j.ajrs.20180601.16
AMA Style
Sobhy Abd Elmonam Younes. Study the Effect of New Egypt Wet Mapping Function on Space Geodetic Measurements. Am J Remote Sens. 2018;6(1):29-38. doi: 10.11648/j.ajrs.20180601.16
@article{10.11648/j.ajrs.20180601.16, author = {Sobhy Abd Elmonam Younes}, title = {Study the Effect of New Egypt Wet Mapping Function on Space Geodetic Measurements}, journal = {American Journal of Remote Sensing}, volume = {6}, number = {1}, pages = {29-38}, doi = {10.11648/j.ajrs.20180601.16}, url = {https://doi.org/10.11648/j.ajrs.20180601.16}, eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajrs.20180601.16}, abstract = {Atmospheric water vapour degrades the accuracy of the results of space geodetic observations due to permanent electric dipole moments. It creates excess path lengths by retarding (slowing and bending) the propagation of the electromagnetic waves that are used in global positioning system (GPS) and very long baseline interferometry (VLBI) observations. It is known that the excess path lengths are less than 30~40 cm at the most, and are the primary obstacles of space geodesy because of the highly variable distribution of water vapour in the atmosphere. In this study, we compared modern five wet mapping functions by evaluating their effects on the tropospheric signal delay and position estimates in GPS data processing, and precise Egypt wet mapping function model is derived based on eight stations of radiosonde data well-distributed over and around Egypt (five stations used to estimate new model and other three as check points). To derive the new Egypt wet mapping function, the troposphere is divided into regular small layers. Ray tracing technique of actual signal path traveled in the troposphere is used to estimate tropospheric slant delay. Real GPS data of five stations (RTK-Network methods) were used for the assessment of new model against the available international models. These international models include Niell (NMF), Black & Eisner (B&EMF), Ifidas (IFMF), Hearing (HMF), and UNBabc MF. The data were processed using Bernese software version 5.0. The results indicate that the new Egypt wet MF model is the best model at Egypt region and has improved the wet tropospheric delay estimation up to 23.3 percent at five degree elevation angles.}, year = {2018} }
TY - JOUR T1 - Study the Effect of New Egypt Wet Mapping Function on Space Geodetic Measurements AU - Sobhy Abd Elmonam Younes Y1 - 2018/03/27 PY - 2018 N1 - https://doi.org/10.11648/j.ajrs.20180601.16 DO - 10.11648/j.ajrs.20180601.16 T2 - American Journal of Remote Sensing JF - American Journal of Remote Sensing JO - American Journal of Remote Sensing SP - 29 EP - 38 PB - Science Publishing Group SN - 2328-580X UR - https://doi.org/10.11648/j.ajrs.20180601.16 AB - Atmospheric water vapour degrades the accuracy of the results of space geodetic observations due to permanent electric dipole moments. It creates excess path lengths by retarding (slowing and bending) the propagation of the electromagnetic waves that are used in global positioning system (GPS) and very long baseline interferometry (VLBI) observations. It is known that the excess path lengths are less than 30~40 cm at the most, and are the primary obstacles of space geodesy because of the highly variable distribution of water vapour in the atmosphere. In this study, we compared modern five wet mapping functions by evaluating their effects on the tropospheric signal delay and position estimates in GPS data processing, and precise Egypt wet mapping function model is derived based on eight stations of radiosonde data well-distributed over and around Egypt (five stations used to estimate new model and other three as check points). To derive the new Egypt wet mapping function, the troposphere is divided into regular small layers. Ray tracing technique of actual signal path traveled in the troposphere is used to estimate tropospheric slant delay. Real GPS data of five stations (RTK-Network methods) were used for the assessment of new model against the available international models. These international models include Niell (NMF), Black & Eisner (B&EMF), Ifidas (IFMF), Hearing (HMF), and UNBabc MF. The data were processed using Bernese software version 5.0. The results indicate that the new Egypt wet MF model is the best model at Egypt region and has improved the wet tropospheric delay estimation up to 23.3 percent at five degree elevation angles. VL - 6 IS - 1 ER -