The article discusses the apparent defi ciency of traditional modeling in dynamical situations, and consequently the utilization of LoS-like path modeling for all relevant refl ections is advocated     GPS ranging is based on the reception of the LoS component of the signals transmitted from the constellation of GPS satellite vehicles (SV), and on measuring the time elapsed in the propagation of appropriately time-marked signal signatures. Even in the absence of any reflected (multipath) signal components, the...

  Purpose of this work is to demonstrate the potential improvement of troposphere calibration using GPS measurements for an ESA deep space probe orbit determination     For interplanetary missions, the determination of S/C state vector (position and velocity) is required both for navigation purposes and science operations. The main error sources affecting S/C tracking data are the solar corona and the interplanetary plasma, which could be removed by using the multifrequency link technique between the probe and the...

Projects don’t fail, people do Present situation It appears that big talk and promises about the technologies (GIS et al) have still not carried weight and conviction with the user – organizations, the ultimate beneficiary of the productivity of the modern technologies. The spatial solutions have still not reached these organizations like urban development authorities. Land Information Technologies (LIT) have not delivered spatial solutions as a matter of routine or policy. Many well known organizations in the government sector...

  The paper proposes basic concepts how to realize the Secure and Safety Tracking System (special for food, food material) between different countries     As the world becomes a smaller place, countries are becoming more dependent on each other in many fields. Goods like industrial products, food and other materials are easily exported and imported by every country. A Secure and Safety Tracking System is indispensable from the viewpoint of defense of country especially in the field of...

Fig. 1 Simulated GPS three-frequency (red: L1, blue: L2, green: L5) multipath error in PRN02 in the LCPC dataset (relative permittivity =3.9) Phase multipath is one of the most crucial error sources in centimetre or millimetre level GNSS high precision positioning. Short-delay multipath is still especially difficult to detect or mitigate by the state-of-the-art hardwarebased techniques. Therefore, processing algorithm-based multipath mitigation methods are crucial for the further improvement of positioning accuracy, either integrated with other techniques or in a stand-alone mode. The effectiveness of some of these is, however, limited by the degrees of freedom in currently available solutions, i.e. insufficient satellites and signals. This problem is similar to the un-robustness and unreliability of some outlier detection techniques used in RAIM and other integrity algorithms in the current GPS system.