Comparison of GPS satellite coordinates computed from broadcast and IGS final ephemerides

Yıl 2018, Cilt: 3 Sayı: 1, 12 - 19, 01.02.2018

Ekrem Tusat Fethi Ozyuksel

https://doi.org/10.26833/ijeg.337806

Cited By: 7

Öz

There are mainly two different orbital information, namely broadcast ephemerides and IGS final ephemerides (IGS rapid, ultra rapid, predicted and final ephemerides) used in the GPS positioning. The broadcast ephemerides used in practice and real time are obtained through assessments derived from the observations from the USA GPS reference stations. Broadcast ephemerides are formed (depending on GPS week) from satellite information and the accuracies they provide are adequate in many GPS applications. On the other hand, several parameters (for example, information about gravity area, improved satellite orbit information, etc.) need to be known in order to attain high accuracy in engineering and geodetic applications. Final ephemeris information can be downloaded from the related web sites via the internet. In this study, Keplerian motion and Keplerian orbital parameters will be explained briefly and extensive information about ephemerides and numerical applications will be given. Within this scope, for GPS satellites, ECEF coordinates of the satellites were computed using the broadcast ephemerides. The coordinates computed by using broadcast ephemerides were compared with the coordinates obtained from the IGS final orbits.

Anahtar Kelimeler

GPS, Broadcast Ephemerides, IGS Ephemerides, Keplerian Orbital Parameters

Kaynakça

• Bidikar, B., Rao, G.S., Ganesh, L., Santosh Kumar, MNVS., 2014. Satellite Clock Error and Orbital Solution Error Estimation for Precise Navigation Applications. Positioning, 2014, 5, 22-26
• Cameron, A., 2015, “More, More, More. Accuracy, Accuracy, Accuracy.” GPS World, September 2, 2015, [Access Date; 14.08.2017]
• Federal Geodetic Control Committee (FGCC), 1989. Geometric Geodetic Accuracy Standards and Specifications For Using GPS Relative Positioning Techniques. Federal Geodetic Control Committee, Version 5.0, p.48.
• Grzegorz, N., Mariusz, F., Zofia, B., 2015. Comparison of GPS Precise Ephemerides Interpolation Methods. 15th International Multidisciplinary Scientific GeoConferences SGEM2015, Section Geodesy and Mine Surveying, pp 161-170, DOI: 10.5593/SGEM2015/B22/S9.020
• Hilla, S., 2010. The Extended Standard Product 3 Orbit Format (SP3-c). National Geodetic Survey National Ocean Service, NOAA, Silver Spring, MD 20910-6233, USA,https://igscb.jpl.nasa.gov/igscb/data/format/sp3c.tx t, [Access Date; 24.07.2017].
• Hofmann-Wellenhof, B., Lichtenegger, H. and Collins, J., 1994. GPS – Theory and Practice. 3rd Edition, SpringerVerlag Wein New York.
• ICD, 1993. Interface Control Document – NAVSTAR GPS Space Segment/Navigation User Interfaces (ICDGPS-200C). ARINC Research Corporation, Revision IRN-200C-004, 12 April 2000.
• IGS, 2017. International GNSS Service. http://www.igs.org/, [Access Date; 14.08.2017]
• Kahveci, M., Yildiz, F., 2001. Global Positioning System Theory-Applications. Nobel Publisher, p.184, Ankara, (in Turkish).
• Parkinson, B., Spilker, J. 1996. Global Positioning System: Theory and Applications. American Institute of Aeronautics and Astronautics, Volume U, p.643, Washington D.C.
• Remondi, BW. 1991. NGS Second Generation ASCII and Binary Orbit Formats and Associated Interpolated Studies. Proceedings of the Twentieth General Assembly, International Union of Geodesy and Geophysics, Vienna, Austria, August 11-24, 1991, 28 pp.
• Rui-xi, J., Xiao-yu, L., Chang-feng, X and Dong-yang, J., 2014. Broadcast Ephemerides Accuracy Analysis for GPS Based on Precise Ephemerides, Applied Mechanics and Materials Vols 602-605 (2014), pp 3667-3670.
• Seeber, G., 1993. Satellite Geodesy: Foundations, Methods, and Applications. W. De Gruyter, p.531, Berlin, New York.
• Stanaway, R., 2007, GDA94, ITRF & WGS84 What’s the difference? Working with Dynamic Datums, SSC 2007, Hobart, Tasmania, Australia
• Tusat, E., Turgut. B., 2003. GPS Ephemerides Effects of Relative Positioning on the Coordinates and Baseline Components. Selcuk University Journal of Engineering, Science and Technology, Vol.19, No.1, pp:65-72, Konya, (in Turkish).
• Warren, DLM., 2002. Broadcast vs Precise GPS Ephemerides: A Historical Perspective. Master Thesis, Department Of The Air Force Air University Air Force Institute Of Technology, p.169, Ohio, USA.
• Yoon, S., 2015. Precise GPS Orbit Determination at National Geodetic Survey: How and Why. 55th Civil GPS Service Interface Committee (CGSIC) Meeting, At the Institute of Navigation GNSS+ 2015 Conference Tampa Convention Center 14-15 September 2015, Tampa, Florida.