Trục tự quay của Trái Đất nghiêng một góc bằng 23,4° so với trục vuông góc với mặt phẳng quĩ đạo,[17] tạo ra sự thay đổi mùa trên bề mặt của Trái Đất trong một năm chí tuyến. Mặt Trăng, vệ tinh tự nhiên duy nhất của Trái Đất, đồng thời cũng là nguyên nhân chính của hiện tượng thủy triều đại dương, bắt đầu quay quanh Trái Đất từ 4,53 tỷ năm trước. | Location-Based Services Time of Arrival TOA The position of a device can be determined by measuring the transferring-time of a signal between the device and the COO. Time Difference of Arrival TDOA Determining a more precise position information of a device by taking advantage of a cells infrastructure and measuring the transferring time of a device to three or more antennas. Ubiquitous Information Management UIM A communication concept which is free from temporal and in general from spatial constraints. Ultra Wideband UWB A technology which enables very short-range positioning information. 276 zn Chapter XXXV Coupling GPS and GIS Mahbubur R. Meenar Temple University USA John A. Sorrentino Temple University USA Sharmin Yesmin Temple University USA Abstr Act Since the 1990s the integration of GPS and GIS has become more and more popular and an industry standard in the GIS community worldwide. The increasing availability and affordability of mobile GIS and GPS along with greater data accuracy and interoperability will only ensure steady growth of this practice in the future. This chapter provides a brief background of GPS technology and its use in GIS and then elaborates on the integration techniques of both technologies within their limitations. It also highlights data processing transfer and maintenance issues and future trends of this integration. Introduct Ion The use of the Global Positioning System GPS as a method of collecting locational data for Geographic Information Systems GIS is increasing in popularity in the GIS community. GIS data is dynamic - it changes over time and GPS is an effective way to track those change s Steede -Terry 2000 . According to Environmental Systems Research Institute ESRI president Jack Dan-germond GPS is uniquely suited to integration with GIS. Whether the object of concern is moving or not whether concern is for a certain place at a certain time a series of places over time or a place with no regard to time GPS can measure it .
