ADDING TIME AND LEVELS OF DETAIL IN THE BUILDINGS MODEL

ABSTRACTThe paper describes two improvements in the available three-dimensional (3D) data model-Urban Data Model (UDM) with surface and body objects. The advantages of these improvements reduce size of data storage; reduce the time cost of data show and visualizing data more realistic than the original model. The paper also added to the model time class to manage historical of changes on the spatial properties of  1D, 2D and 3D object. The levels of detail added to show buildings at four levels from simple to complex. Event class in the model should record the reasons to create changes on the buildings in their evolution.Keywords.  3D, data model, spatio-temporal model

A Status Data Transmitting System for Vessel Monitoring

This paper presents a status data transmitting system suitable for vessel monitoring. The system consists of four main parts, which are a status data module, a frequency synthesizer, a power amplifier and a horn antenna. The status data module packs information of the identification, longitude, latitude and state of the vessel into data frames. FSK/MSK/GMSK schemes were used to modulate the data. The frequency synthesizer was designed with very high stability over temperature and very low frequency tolerance. The power amplifier provides 130 W output power at S band. The impedance bandwidth of the horn antenna can be controlled using the beveling technique