The International GPS Service (IGS) has provided GPS orbit products to the scientific community with increased precision and timeliness. Many users interested in geodetic positioning have adopted the IGS precise orbits to achieve centimeter level accuracy and ensure long-term reference frame stability. Currently, a differential positioning approach that requires the combination of observations ...

Introduction The development of Earth-observation techniques based on the use of navigation signals can be traced back to the use of GPS in geodetic applications to provide astonishing precision, such as the determination to within a few centimetres of the relative positions of points on the Earth’s surface separated by several thousand kilometres. This ultra-precise positioning of fixed GPS re...

Precise point positioning with satellite navigation signals requires knowledge of satellite code and phase biases. In this paper, a new multi-stage method is proposed for estimating of these biases using measurements from a geodetic network. The method first subtracts all available a priori knowledge on orbits, satellite clocks and multipath from the measurements to reduce their dynamics. Secon...

The aim of this paper is to discuss the development of an automatic, low-cost system that exploits current or near future wireless communications technology to enable continuous tracking of the location of devices in all environments. The development of such a wireless sensor network involves system design, digital signal processing, protocol development, extraction of ranges and localisation. ...

Precise positioning in indoor environments faces different challenges than outdoors. While indoor environments are limited in size to rooms and buildings, outdoor positioning capabilities require regional or even global coverage. Secondly, the difficulty of receipting satellite signals indoors has triggered the development of high sensitive and AGNSS receivers – with many issues remaining unsol...

The Global Positioning System, or GPS, is a key technology for both the civilian and scientific research markets. GPS provides users with precise geodetic positioning and time determination. Most GPS receivers require specialized hardware and complex software to operate. One receiver, originally designed to run in DOS, will be the focus of a code migration to RTLinux. The major aspects of the m...

Using mobile smart devices to provide urban location-based services (LBS) with sub-meter-level accuracy (around 0.5 m) is a major application field for future global navigation satellite system (GNSS) development. Real-time kinematic (RTK) positioning, which is a widely used GNSS-based positioning approach, can improve the accuracy from about 10-20 m (achieved by the standard positioning servic...

SUMMARY The fast development of Global Positioning System (GPS) technology provides more precise and rapid surveying in geodetic applications than the traditional terrestrial positioning techniques. Therefore, considerable savings on time, labour and cost are achieved by GPS measurements. The geometric height supplied by GPS is ellipsoidal height and it needs to be transformed to orthometric he...

Location-based services (LBS) to date offer information and specific services tailored to the current geographic usage environment. The “location service” delivering the required location information in turn is provided by a location platform using specific positioning technologies and geodetic data (e.g. maps). Currently no single positioning technology or location platform can provide a locat...

Let G=(V,E) be a simple connected graph of order p and size q. A decomposition of a graph G is a collection π of edge-disjoint subgraphs G_1,G_2,…,G_n of G such that every edge of G belongs to exactly one G_i,(1≤i ≤n). The decomposition 〖π={G〗_1,G_2,…,G_n} of a connected graph G is said to be a distinct edge geodetic decomposition if g_1 (G_i )≠g_1 (G_j ),(1≤i≠j≤n). The maximum cardinality of π...