The Research Of Key Technology On The Realization And Maintainance Of TRF

Global Navigation Satellite System and earth observing system will develop very fast in the 21th century, and these will help human beings to understand the earth in the unexpected high level, so it is urgent to define the Terrestrial Reference System according to the best discipline of the earth's motion and establish Terrestrial Reference Frame (TRF) to provide service. The technologies in establishment and maintainance of TRF include the datum definition of TRF, intra-technique combination and inter-technique combination are researched in the dissertation. The research contents of the dissertation are based on the independent COMPASS global navigation satellite system, mainly on the key technologies of establishment and maintainance of independent COMPASS Terrestrial Reference Frame (CTRF). The main achievements and concerned items of the dissertation are as following:1) The theoretical foundation of establishment of TRF is introduced and analyzed in this dissertation. Firstly, the datum definition of ITRF series is summarized and some comparison is made. Secondly, ITRF combination model is fully introduced and some comparison is made between IERS official agency and other agency. At last, the constraints and its treatment in datum definition of ITRF is analyzed.2) One of the key technologies in establishment and maintainecne TRF is discussed. Fisrtly, the application of regularization method in the datum definition of TRF is analyzed and investigated. Secondly, the Tykhonov-Phillips with A-optimal design regularization method is adopted to define TRF datum, giving corresponding examples and results analysis. At last the difference and connection between this method and the adoption of minimum constraints is compared, the comparison shows the coordinate differences between these two methods are in 3cm, and most of them are in 2cm.3) Another key technology in establishment and maintainecne TRF is researched, mainly on the intra-technique combination model and process. Using the SINEX files from different Analysis Centers (AC) to finish the intra-techique combination of GPS, VLBI and SLR, the velocity field and the time series of some stations are given, and some results are also analyzed. According to the comparision, the results and those from other research agencies are in the same level. 4) The other key technology in establishment and maintainecne TRF is researched, mainly on the inter-technique combination. The SINEX files published by IGS, IVS and ILRS separately are adopted as the input data, and the current local tie is analyzed, adding the appropriate local tie information, the combination of space geodetic data is finished, and the results are compared to the ITRF2005, the comparision shows that the results and those from ITRF2005 are in the same level.5) The TRF datum definition, establishment and maintainance are researched, the scheme of TRF datum definition, establishment is proposed, and the implementation plan of TRF maintainance is also given.6) On the basis of introduction of Galileo Geodetic Service Provider (GGSP) and the TRF used by Galileo system-Galileo Terrestrial Reference Frame (GTRF), considering reality of our country, the mode of definition, establishment, maintainance of COMPASS Terrestrial Reference Frame (CTRF) are proposed, and the process, period and contents of CTRF are also given in the dissertation.7) On the basis of the scheme of CTRF definition, establishment, maintainance and validation, some simulation experiments are performed using GPS data and GPS stations. The results from the simulation on the effect of distribution on the TRF reveal that about 22 stations in global distribution will basically meet the requirements of the TRF establishment, in order to establish and maintainance of the long-term and accurate TRF, about 30 stations in global distribution are required. The results from the intra-technique combination reveal that this combination will help to improve the stability and Reliability.