Global Positioning System (GPS) provides a method for directly obtaining instantaneous position and velocity estimates using satellites-based passive range measurements. GPS is whole day, all-weather, passive, satellite positioning system. Inertial Navigation (INS) navigation aid system that uses computer Measurement Unite (IMU). IMU includes motion sensors rotation to continuously calculate re...

RTKLIB is an open source program package for RTK-GPS developed by the authors. RTKLIB is a compact and portable program library written in C to provide a standard platform for RTK-GPS applications. The library implements fundamental navigation functions and carrier-based relative positioning algorithms for RTK-GPS with integer ambiguity resolution by LAMBDA. RTKLIB also supports data communicat...

Researchers at the IESSG at the University of Nottingham, in conjunction with colleagues from Brunel University, have carried out deflection monitoring work on structures, notably bridges, for a decade. Initial work was carried out 101 ION GNSS 18th International Technical Meeting of the Satellite Division, 13-16 September 2005, Long Beach, CA on the Humber Bridge, London’s Millennium Bridge an...

A new inverse diffraction algorithm has been developed to estimate the fine-scale ionospheric electron density variations that cause equatorial scintillation in GPS signals. This work is part of an effort to image the disturbed ionosphere in order to better understand scintillation from a scientific standpoint. The new algorithm relies on a physical model of how electron density irregularities ...

The signals ttansmitted by Block II satellites of the Global Positioning System (GPS) can be degraded to limit the highest accuracy of the system (10m or better point positioning) to authorized users. This mode of degraded operation is called "Selective Availability" (S/A). SlA involves the degradation in the quality of broadcast orbits and satellite clock dithering. We monit<X'ed the didtered ...

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 Global Navigation Satellite System (GNSS) plays an important role in positioning and navigation applications. The Global Positioning Service (GPS) augmentation is to achieve more reliable and accurate navigation solutions. The presently available traditional GNSS receivers are hardware based receivers which are not flexible and cannot be easily upgraded to acquire the signals from other GNS...

Embedded GPS receivers have become commonplace with the proliferation of GPS navigation systems into all but the least expensive vehicle and cell phone lines. As more manufacturers embed low-cost GPS receivers into their products, the need for low-cost GPS signal simulators has also grown. Controlled virtual testing is vital in ensuring the expected system performance. NAVSYS developed a low co...