This paper essentially deals with the effects of equatorial ionization anomaly gradient on space-based navigation systems like GPS. The equatorial region of the ionosphere, which extends about ±30dip about the magnetic equator, is characterized by a steep latitudinal gradient, not only in the maximum ionization but also in the total electron content (TEC), through a major part of the day. This ...

Master of Electrical Engineering Program Cornell University Design Project Report Project Title: Ionospheric irregularities as observed from the GPS reference station in Singapore, March 2002 Author: Pongabha Abhakara Abstract: In regions near the geomagnetic equator, the phenomenon of ionospheric irregularities that causes scintillations in Global Positioning System (GPS) signals occurs freque...

The world-wide use of GPS satellites for navigation and positioning offers the unique chance for permanent monitoring the total electron content (TEC) of the ionosphere on global scale. Based on the analysis of GPS-derived TEC maps computed at DLR/DFD Neustrelitz for the European area on a routine base with a time resolution of 10 min the paper demonstrates the power of this new tool to detect ...

This work studies the sudden increases in total electron content of the ionosphere caused by the very intense solar flare on July 14, 2000. Total electron content (TEC) data observed from a Global Positioning System (GPS) network are used to calculate the flare-induced TEC increment, dTECf, and variation rate, dTECf/dt. It is found that both dTECf/dt and dTECf are closely related with the solar...

The energetic events on the sun, solar wind and subsequent effects on the Earth’s geomagnetic field and upper atmosphere (ionosphere) comprise space weather. Modern navigation systems that use radio-wave signals, reflecting from or propagating through the ionosphere as a means of determining range or distance, are vulnerable to a variety of effects that can degrade the performance of the naviga...

The ionospheric total electron content (TEC) in the low-latitude Singapore region (geographic latitude 01.37° N, longitude, 103.67° E, geomagnetic latitude 8.5° S) for 2010 to 2011 was retrieved using the data from global positioning system (GPS)-based measurements. The observed TEC from GPS is compared with those derived from the latest International Reference Ionosphere (IRI)-2012 model with ...

the least squares harmonic estimation is applied to the hourly time-series of total electron contents (tec) derived from ionospheric models using seven years of gps observations processed by bernese software. the frequencies of dominant spectral components in the spectrum are estimated. we observe significant periodic patterns with periods of 24 h and its fractions 24h/n, n=2,…,11, which are th...

I.inc-of-sight ionosphere measurements derived from differcncing dual-frequency Global Positioning System (GPS) range data are corrupted by instrumental biases in both the receiver and GPS satellite transmitters due to hardware delays in the L1 and L2 signal paths, The lineof-sight differential delay can be modeled as the sum of a rccciver bias, a satellite transmitter bias, and the line-ofsigh...