The currently available triple-frequency signals give rise to new prospects for precise point positioning (PPP). However, they also bring bias, such as time-varying parts of the phase bias in hardware receivers and satellites due fact that dual-frequency clock products cannot be directly applied observation. These parameters generate phase-based inter-frequency (PIFCB), which impacts PPP. PIFCB...

Introduction GPS receivers are now widely used for Low Earth Orbit (LEO) spacecraft applications for both scientific and commercial programmes. New applications are also under study, such as navigation in Geostationary Earth Orbit (GEO) and Geostationary Transfer Orbit (GTO), space rendezvous manoeuvres and atmospheric reentry, for which GPS receivers are promising candidates as navigation sens...

In recent years techniques have been developed to obtain integrated water vapor along slant paths between ground-based Global Positioning System (GPS) receivers and the GPS satellites. Results are presented of an observing system simulation (OSS) to determine whether three-dimensional water vapor fields could be recovered from a high-resolution network (e.g., with 40-km spacing) of GPS receiver...

Bandpass sampling architectures, also called subsampling architectures, exhibit several advantages over super-het architectures. First, the complexity of subsampling architectures is significantly lower since no Phased-Locked-Loop (PLL) is required. A direct consequence is that downconversion from RF to IF can be achieved with significant power savings as compared to the super-het architecture....

This paper describes an experiment involving a professional downhill skier equipped with GPS and MEMS-IMU, as well as a triad of magnetometers and a tactical-grade inertial unit. The experiment illustrates the navigation performance of GPS/MEMS integration compared to high-quality GPS/INS integration challenged by the environmental conditions and dynamics of ski-racing. The MEMS sensors’ output...

Uydularla konum belirleme ve navigasyon (GNSS) uygulamalarında, Seçimli Doğruluk Erişimi (SA: Selective Availability) gibi kasıtlı bozmalar haricinde, en önemli hata kaynaklarından birisi iyonosferdir. İyonosferde atomlardan kopmuş serbest elektronların sayısı elektromanyetik dalgaların yayılmasını değiştirmeye yetecek kadar çoktur. İyonosferik etki, bu elektronlar nedeniyle, uydu kod ölçülerin...