The Indian Regional Navigation Satellite System (IRNSS) is an emerging satellite based navigation system offering an independent positioning and timing service over India and neighboring regions. Based on satellite laser ranging data collected by selected stations of the International Laser Ranging Service (ILRS) precise orbits have been determined for the first pair of inclined geosynchronous ...

Position determination is one of the key-elements of Location Based Services (LBS). One popular approach to positioning for LBS is using a Global Navigation Satellite System (GNSS). With such a system, three-dimensional positioning is available anywhere on, and above the Earth, in principle without any local or regional infrastructure. On the other hand, as satellite based radio positioning rel...

Providing navigational aids to assist users in finding information in hypertext systems has been an ongoing research problem for well over a decade. Despite this, the incorporation of navigation aids into Web search tools has been slow. While search engines have become very efficient in producing high quality rankings, support for the navigation process is still far from satisfactory. To deal w...

The current Federal Radio Navigation Plan presents a plan that includes phasing out of existing radio-navigation aids as part of the transition to sole-means-GPS navigation in the United States. GPS based systems are also being envisioned as becoming the primary means of air traffic control resulting in the retirement of older primary and secondary surveillance radar (SSR) systems. This paper d...

Navigation aids such as bookmarks, target prediction, or history mechanisms help users find desired objects in visual workspaces. They work by highlighting objects that may be important, and they can improve performance in spaces where the territory is not well known. However, by making navigation easier, they may also hinder acquisition of a mental map of the space, reducing navigation perform...

Navigation aids provide users with a route as a sequence of turn by turn instructions, each of which guides the user from one decision point to the next. Along the extensive research on enriching navigation aids with the elements of spatial cognition, this research provokes the idea of including cognitive subdivisions of space in outdoor navigation. As the first step, we present the results of ...

Combining the technologies of the satellite formation flying with the satellite to satellite tracking (SST), the effect of satellite formation flying on autonomous navigation is analyzed in this paper. Considering the effect of satellite formation flying, the autonomous navigation system with relative inertial-position vector measurement is proposed firstly. Then, observability of the system wi...