SOME ASPECTS ON INTENSIFYING THE GEODESIC NETWORK BY MEANS OF G.P.S. MEASUREMENTS FOR THE PURPOSE OF CADASTRAL SERVICES IN WESTERN ROMANIA PUBLISHEDOctavius Nicolae COLTAN, Valeria CIOLAC
Abstract The paper is aimed at network sampling by intensifying the geodetic network to achieve cadastral works outside the city limits of Lăţunaş, Timis county. Given the scope of the project, the location as compared to the national geodetic network, and the kind of relief in the given area, we opted for sample networking by means of GPS measurements. We chose to conduct the measurements by employing the static method, which provides the highest precision. The sampling network, hereafter denominated secondary network, was placed approximately at the centre of the measurement area. In order to achieve a high level of accuracy, we opted for using higher order geodetic signals (order I and II). The signals employed as a base were chosen so as to form a triangle. However, the vicinity of the focus area to the Serbian border imposed that the two newly determined points remain outside the southern base of the main network. Nonetheless, given that the distances were well under the maximum accepted value, 10% of the base lengths, errors are virtually negligible. The working equipment consisted of 4 GPS dual frequency receivers, namely: two receivers from the HIPER Plus series and two from the HIPER Pro series of the Japanese manufacturer TOPCON. The latter have a built-in radio mode, thus allowing configuration in the RTK system. Being of dual frequency, the receivers were able to record P code signals. Given the possibility to use up to 20 channels on the receivers, it was also possible to make simultaneous use of both satellite systems. It was established that three signals from the national geodetic network be stationed on the sample area with fix receivers: Sumiga (order I), Dealul Corcanu (order II) and S-E Moraviţa (order I). The second phase on the land plot includes the execution of the cadastral surveys, with the four teams perambulating according to the planned works. The first three teams covered the signals from the national geodetic network, while the fourth team perambulated the area where the three new points had been positioned. A surveying session was completed for each of the new points with three fix references on old points and a reference point on the new points: S100, S200, and S300. The next step was to download and process the field data by using the Leica Geo Office Combined software. The drafting of the plans for primary and secondary networks was performed by using the AutoCAD program. The new reference points outside the city limits of Lăţunaş will be used in the cadastral surveying to be performed.