CHZ-Ⅱ海洋重力仪研制与实践

Development and practice of CHZ-Ⅱ marine gravimeter

海洋重力仪是获取高精度高分辨率海洋重力场的重要仪器,主要应用于资源勘探、大地水准面精化、海洋科学研究和重力辅助惯性导航等领域。我国现有的海洋重力仪主要依靠国外进口,不仅价格高,而且在仪器的引进、维护等方面存在诸多的不便。在科技部首批重大科学仪器专项的支持下,基于CHZ海洋重力仪成功研制出具有完全自主知识产权的CHZ-Ⅱ弹簧式海洋重力仪。该新型重力仪采用金属零长弹簧作为测量元件,其独特的轴对称垂直悬挂结构可克服交叉耦合效应;高精度伺服控制技术及强阻尼的应用可克服载体扰动的影响,确保仪器在不同海况下保持测量精度;高精度恒温技术及温度补偿技术可消除环境温度波动对仪器测量精度的影响。本文介绍了该仪器的工作原理、系统构成、技术特点及测试结果。静态试验表明其月漂移优于3 mGal;码头系泊试验表明其动态精度达到0.2 mGal,能清晰反映海潮的重力变化特征;总航程超过5万海里船载试验表明其综合测量精度优于1 mGal。仪器在精度和稳定性上达到与国内外同类仪器并跑水平,可替代当前国外进口的海洋重力仪。

Marine gravimeter is an important instrument to obtain high-precision and high-resolution marine gravity field,which is mainly used in resource exploration,geoid refinement,marine science research and gravity assisted inertial navigation.The existing marine gravimeters in China mainly rely on foreign imports,which not only have high prices,but also have many inconveniences in the introduction and maintenance of the instruments.With the support of the major scientific instrument projects of the Ministry of Science and Technology,the CHZ-Ⅱspring type marine gravimeter with completely independent intellectual property rights has been successfully developed based on the CHZ marine gravimeter.The new gravimeter uses metal zero length spring as the measuring element,and its unique axisymmetric vertical suspension structure can overcome the cross coupling effect.The application of high-precision servo control technology and strong damping can overcome the influence of carrier disturbance and ensure that the instrument maintains measurement accuracy under different sea conditions.High precision constant temperature technology and temperature compensation technology can eliminate the influence of ambient temperature fluctuation on the measuring accuracy of the instrument.This paper introduces the working principle,system structure,features and test results of the instrument.The static test shows that its monthly drift is better than 3 mGal;the wharf mooring test shows that its dynamic accuracy reaches 0.2 mGal,which can clearly reflect the gravity variation characteristics of sea tide;the ship borne test with a total voyage of more than 50000 nautical miles shows that the comprehensive measurement accuracy is better than 1 mGal.To sum up,the accuracy and stability of the instrument have reached the level of the same kind of instruments at home and abroad,which can replace the current imported marine gravimeter.