Based On Tidal Marine GPS Measurement Method

With the development and application of GPS technology, a lot of new researchdirections arise. The ocean tide is the most familiar phenomenon in the ocean. TheOcean Tide Loading/OTL is the serious error source in the GPS precise positioningalong the coastal zone. According to the OTL effect, the GPS will become thesensitive sensor to monitor the characteristics of the ocean tide. This will enrich theobservation method of the ocean tide. It has the significance in the science researchand application.Based on three global ocean tide models (FES2004, GOT4.7and NAO.99b), theeffect of the OTL on four GPS sites has been studied in the Chinese coastal zone. Theresults show that the OTL effect reaches up to3cm on Xisha site, and the NAO.99b ismuch suitable for Chinese coastal zone.Based on the PPP and GPS data from the Chinese coastal zone, the dynamicvariation series, including the OTL, has been calculated in3GPS sites namely asChengshantou, Pingtan, Zhapo. After spectral analysis of two-months results, theeight constitutes of the OTL are obtained. These results are compared with thepredictions from the global ocean tide models (FES2004, NAO.99b and GOT4.7). Itis shown that the results of S2, K2, K1derived from GPS are good agreement withthose from GOT4.7, NAO.99b model, while K1, K2, S2aren’t consistent with themodels, the reason is for further study. The results also show that the GPS-derivedapproach is feasible in theory.This research will provide a new method to monitor the ocean tide variation,but also offer the OTL correction service for the precise positioning around theChinese ocean. This method will help the GPS to service the disaster prevention andreduction.