Abstract:
Objectives High precision global navigation satellite system (GNSS) positioning results are gene‑rally expressed under the international terrestrial reference frame(ITRF), but China's surveying and mapping results require the use of the China geodetic coordinate system 2000 (CGCS2000). High precision velocity field model is the key to achieve the conversion between ITRF2014 and CGCS2000. At present, most studies use a single method to build the velocity field model, without in-depth study of the impact of different parameter settings on the construction of the velocity field, and without discussion of the performance of different methods in different speed directions.
Methods For this reason, based on the data of 260 continuously operating reference stations （CORS) of the crustal movement observation network of China (CMONOC) and 90 International GNSS Service stations within and around China, and based on the tension spline function method and the Kriging method. We use different parameter settings to build a 1 mm high-precision velocity field model covering the country, establish 3 methods with the highest accuracy in 3 directions of east, north, up, and use these 3 methods to build a combined velocity field field. The model is applied to the coordinate transformation of ITRF2014 and CGCS2000 of CORS nationwide.
Results The research results indicate that the overall conversion accuracy of the combined velocity field is about 2.261 cm, and the conversion accuracy of a single directional component is maintained at around 1.3 cm, which can achieve benchmark conversion of centimeter level accuracy for large-scale surveying and mapping results in China.
Conclusions Based on experiments, we conclude that constructing the optimal component velocity field and forming a combined velocity field through different methods can effectively improve the accuracy of the overall velocity field model and be further applied in practice.
下载:
