Recently, several researchers have studied a vector tracking loop, such as a vector delay lock loop (VDLL) and a vector frequency lock loop (VFLL), to obtain an improved tracking performance in GPS receiver [1~6]. The vector based tracking loop technique uses the correlation of each satellite signal and user dynamics. The receiver with the vector tracking loop can get enough total signal power ...

With the increasing number of satellite launches, especially in Low Earth Orbit (LEO), optical tracking can offer a convenient enhancement precision and availability. Spaceborne active illumination devices, such as LED payloads, significant improvement to observations, extending observability interval whole eclipse time performing optimized flash sequences for identification, orbit determinatio...

Against the range-dependent accuracy of the tracking radar measurements including range, elevation and bearing angles, a new hybrid adaptive Kalman filter is proposed to enhance the performance of the radar aided strapdown inertial navigation system (INS/Radar). This filter involves the concept of residual-based adaptive estimation and adaptive fading Kalman filter and tunes dynamically the fil...

This paper presents a low-profile user-terminal antenna for mobile bi-directional Ka-band satellite communication networks for emergency scenarios. We have devised an antenna with a circularly polarised radiation pattern and dual-band capability, which addresses a hybrid tracking. The principle of operation of a rectangular antenna panel applying a dual-band partially reflective surface (PRS) o...

Locata positioning technology was developed to address the shortcomings of current technologies for reliable positioning in challenging environments such as when GPS satellite coverage is poor or not available. Previous research in this area has demonstrated proof-of-concept for the Locata technology using a first generation prototype system. In this paper details of Locata’s next generation sy...