ABSTRACT
Dynamic gravity field measurement based on the cold atom absolute gravity measurement system has important applications in geological exploration, gravity field mapping and other fields. The inertial stabilized platform is the key component of the dynamic cold atom absolute gravity measurement system, which can isolate the interference of carrier angle motion and keep the atomic gravimeter probe in the horizontal attitude during the measurement process. In this paper, according to the dynamic measurement requirements of atomic gravimeter, a high-precision two-axis inertial stabilized platform system is designed. The relationship between attitude angle and gravity measurement error is analyzed, and the stability of the system is enhanced by lead-lag method. Then the static vertical vibration power spectrum of the platform is measured to consider its influence on dynamic gravity measurement. Finally, a dynamic gravity test experiment was conducted in the Yellow Sea to verify the attitude control accuracy of the platform, and the attitude data of the platform under different heading were evaluated. The attitude standard deviation of the platform was better than 4 × 10-5 rad, and the absolute gravity standard deviation of the linear round-trip measurement reached 1.49 mGal. The experimental data show that the inertial stabilized platform can meet the dynamic measurement requirements of the cold atom gravimeter.
ABSTRACT
All cases with total anomalous pulmonary venous connection (TAPVC) were reported in neonates and children in the previous literature. This report describes the only case in which a mixed supra- and intracardiac TAPVC was discovered in a 25-year-old adult female and multidetector-row computed tomography (MDCT) angiography was used in its pre- and postoperative evaluation. Multidetector-row computed tomography angiography is superior to echocardiography in showing the draining sites and courses of the anomalous connected pulmonary veins, as well as postoperative evaluation in a patient with mixed TAPVC. It indicates that MDCT angiography may be a more suitable diagnostic modality for use in the pre- and postoperative evaluation of the mixed TAPVC.
