This paper presents ambiguity resolution in the range-based ZigBee positioning system. The system is using the phase shift measurements to determine the distances between user and anchors. In this paper, the ambiguity is defined as the number of full reps of a certain distance added to the measurement result. The way of resolving ambiguities in the positioning system is described and an experiment results are presented. Featured algorithm is successful in finding ambiguities and correct location of the user.
This paper presents the analysis of PDOP factors for a ZigBee ground – based augmentation systems. It presents the idea of such a system followed by the results of assessment of application in Gdansk Marina. The results of the experiment show that the application of ZigBee can significantly improve PDOP value in harsh measurement environment. The analysis shows that it is possible to select an optimal location of ground-based transceiver on the basis of predicted trajectory and obstructions measured with laser scanning.
On the base of leveling data, three maps of vertical crustal movements were developed (Wyrzykowski, 1971; Wyrzykowski, 1985a; Kowalczyk, 2006a). Also two maps of vertical crustal movements were created (Wyrzykowski 1990, Kowalczyk, Rapiński 2011). In the above mentioned elaborations, the vertical crustal movements were calculated from two subsequent first order leveling campaigns. To include more data, results of all four leveling campaigns in Poland were accumulated and digitalized. One, unified database was developed on the basis of collected and unified data set of unadjusted observations (Kowalczyk, Bednarczyk, 2009; Kowalczyk, Bednarczyk, Kowalczyk, 2011). First trials of common use of three first order leveling campaigns were performed in 2008 (Kowalczyk, 2008). Though the available leveling data was not complete. The goal of this paper is to describe a trial of common adjustment of relative vertical crustal movements on the basis of three first order leveling campaigns in Poland.
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Pseudolites are ground based GNSS signal transmitters that have already been used in the project where visibility to the GNSS satellites is limited, however there are still many issues that need enhancement. A prototype of a low-cost pseudolite is being designed and assembled at the University of Warmia and Mazury. The goal of the project is to apply the pseudolite as an augmentation to GNSS positioning tasks in geodetic engineering projects. This paper presents the results of first prototype testing in the area of code generation, carrier frequency and signal power.
This paper gives a proposition of a model of the maximum range of a range finder. It is based on the laser range equation and a Phong model. It shows how theincidence angle affects the maximum range when measuring to the surface that characterizes with diffuse – specular refection. The results shows that one can determine the boundary angle for which the optimum performance of maximum range is maintained.
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