| Summary: | 碩士 === 清雲科技大學 === 土木與防災研究所 === 95 === Nowadays, the horizontal precision of RTK is about 2 cm, and the height precision is about 5 cm, GPS has been wildly applied on lots of areas. Since the speed of internet and wireless communication become more and more, RTK become the hottest topic in many countries, and the advanced countries are building this system actively.
Due to the GPS signal might be affected by troposphere, ionosphere and orbit error, the raw data error. When we measure using RTK technology, we have to notice the distance between rover station and reference station. Also, when radio is used in city area, it often affects by factors such as environment and makes the work abort.
Now, a new technology, Virtual Reference Station, also called as e-GPS in Taiwan, is applied to calculate the systematic error by using the real-time data from GPS Network, and provide it to users via GSM or GPRS.
In this research, two kind of GPS receiver are employed to elevator the internal precision and exterior precision. The horizontal precision of N direction and E direction are around 3 cm, and the height precision of h direction is about 6 cm.
The Ministry of Interior announced the Taiwan Datum ten years ago, and the referencial frame has changed after some earthquakes and crustal deformation. Some controlling points in Northern and Eastern were measured by using e-GPS Taiwan converted the coordinates to TWD97. The results showed that the datum in Taoyuan area did not change too much. After converting the coordinates, the horizontal error of Hualien area became better and the errors are from 2-30 cm to 2-3 cm.
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