Preparation And Application Of Marine Gravity Data Preprocessing Software

We developed a set of marine gravity data processing software system by using the Visual Basic 6.0 computer language, the familiar data processing steps and the specification for marine gravity survey. The system can make our data processing work be integrative, enhance our efficiency and ensure the accuracy of data processing. A satisfactory result was got in processing one sea area section data of Nanhai sea by using this system, proving that this system had characters of convenience, veracity and expeditiousness. The result was analysed and applied.We can verify the dynamic properties of the marine gravity-meter by comparing the relationship between the E?tv?s Correction data and the gravity data. The actual delay-time in the filter state (sea state) of 2 is about 60s,which is more actual than 110s given by the gravity-meter manufacture. It can help us minimize positioning-error during data processing and improve the accuracy of the measurements. We can also validate the veracity and credibility of the marine gravity-meter by analysing the reliability during the measurements course at sea, which is the precondition for us to gain precise data.The regular network gravity data corrected by 60s delay-time and by 110s delay-time was used to evaluate the crossover errors and to do adjustment. The result indicates that the measurement precision of the line network corrected with the delay-time of 60s is about 1.40mGal before adjustment processing and about 0.77mGal after adjustment processing. The measurement precision of the line network corrected with the delay-time of 110s is about 1.62mGal before adjustment processing and about 0.96mGal after adjustment processing. The result intensively validates that the method named verifying the delay-time of marine gravity-meter by the vessel turn-manoeuvre is necessary and useful.The adjustment method formulated by Song Wenyao was analysed and compared with the least square adjustment method formulated by Liu Baohua at the end of the paper. Their principia and processing results showed that one method was equal to another in the effect of regular network marine gravity adjustment processing. The least square adjustment method was more convenient than the adjustment method formulated by Song Wenyao in the effect of regular network marine gravity adjustment processing. The least square adjustment method was easy carried out by the computer language.