Lecture at Higher Institute of Engineering and Technology, El-Behira, Egypt
Associate Professor at Faculty of Engineering, Menofia University, Egypt
Professor at Faculty of Engineering, Benha University, Egypt
Abstract. An apparent delay is occurred in GPS signal due to both refraction and diffraction caused by the atmosphere. The second region of the atmosphere is the ionosphere. The ionosphere is significantly related to GPS and the refraction it causes in GPS signal is considered one of the main source of errors which must be eliminated to determine accurate positions. GPS receiver networks have been used for monitoring the ionosphere for a long time.
The ionospheric delay is the most predominant of all the error sources. This delay is a function of the total electron content (TEC). Because of the dispersive nature of the ionosphere, one can estimate the ionospheric delay using the dual frequency GPS.
In the current research our primary goal is applying Precise Point Positioning (PPP) observation for accurate ionosphere error modeling, by estimating Ionosphere delay using carrier phase observations from dual frequency GPS receiver. The proposed algorithm was written using MATLAB.
The proposed Algorithm depends on the geometry-free carrier-phase observations after detecting cycle slip to estimates the ionospheric delay using a spherical ionospheric shell model, in which the vertical delays are described by means of a zenith delay at the station position and latitudinal and longitudinal gradients. Geometry-free carrier-phase observations were applied to avoid unwanted effects of pseudorange measurements, such as code multipath. The ionospheric estimation in this algorithm is performed by means of sequential least-squares adjustment.
Finally, an adaptable user interface MATLAB software are capable of estimating ionosphere delay, ambiguity term and ionosphere gradient accurately.
This preprint has been withdrawn.
How to cite. Elsayed, A., Sedeek, A., Doma, M., and Rabah, M.: Vertical Ionosphere Delay Estimation using Zero Difference GPS Phase Observation, Ann. Geophys. Discuss. [preprint], https://doi.org/10.5194/angeo-2018-113, 2018.
Received: 08 Oct 2018 – Discussion started: 25 Oct 2018
We have over viewed an algorithm which can be used to estimate ionospheric delays of GPS observations using single GPS receiver using a spherical ionospheric shell model. This Algorithm depends on the geometry-free carrier-phase observations after detecting cycle slip. The ionospheric estimation in this algorithm is performed by means of Sequential least-squares adjustment. This study is performed on ten IGS stations, and results of the ionosphere delay was compared with GAPS software results.
We have over viewed an algorithm which can be used to estimate ionospheric delays of GPS...