Modern GPS carrier phase-based survey techniques such as "rapid static" and "stop & go" are fast becoming the standard operational modes for building local geodetic control networks or for the densification of an existing network. However, such techniques do have some challenges when used together within a single survey project. For example, these mixed-mode GPS surveys do result in incompatibl...

in this paper a practical method for tropospheric effects on gps derived coordinates in absolute mode is presented. gps observations at the permanent gps stations can be used as source of information for the modeling. the developed model is a time-dependent model and as such differs from usual tropospheric models, which are based on atmospheric parameters, i.e. temperature, pressure and humidit...

In GPS data processing it is not uncommon to eliminate the presence of ionospheric delays by taking certain linear combinations of the carrier phase data. This approach is in fact equivalent with a processing of the original, not combined, L1 and L2 phase observations in which the ionospheric delays are modelled as unknown parameters. When using phase data only, the presence of the unknown iono...

This paper shows an application of the fuzzy-logic approach to mobile mapping issues, presenting results of fuzzy processing of the C/A-code-based GPS measurements (standalone static positioning), whose accuracy depends essentially on the satellite observation geometry, expressed numerically by the GDOP (Geometrical Dilution Of Precision) factor, and on the Signal-to-Noise Ratio (SNR). A fuzzy ...

A GPS multi-antenna system consisting of multiple off-the-shelf GPS sensors has been successfully developed and extensively tested in operational marine environments. The advantages to use such a system are the flexibility in the selection of GPS sensors, the cost-effectiveness of the system with the emerging low-cost high performance GPS products and the increased productivity of equipment whi...

The development of the first AGGA (Advanced GPS/GLONASS ASIC) device was initiated within ESA’s Earth Observation Preparatory Programme (EOPP) in order to support the Earth observation applications of navigation signals. After prototyping iterations, the flight component known as AGGA-2 was manufactured under Atmel product code T7905E [0]. The AGGA-2 is a space-qualified digital integrated circ...

Due to their weak received signal power, Global Positioning System (GPS) signals are vulnerable to radio frequency interference. Adaptive beam and null steering of the gain pattern of a GPS antenna array can significantly increase the resistance of GPS sensors to signal interference and jamming. Since adaptive array processing requires intensive computational power, beamsteering GPS receivers w...