基准地磁台选定基线值约束方法研究

Research on the constraint method for selecting baseline values of reference geomagnetic stations

《地磁站网运行管理技术细则》《电磁学科观测资料质量评比办法》对基准地磁台绝对观测基线值的选定无约束条件或规定,使得观测人员在进行基线值选定时无据可依,容易导致基线值错误,进而导致地磁绝对值错误。通过2种对选定基线值的约束方法,可降低基线值错误率,提高数据质量。2种方法分别为:①直接约束法(选定基线值约束):通过基线值预处理、温漂消除、“2σ”准则等方法,实现对选定基线值的约束和判定,有效率达60%以上;②间接约束法(绝对值约束):通过绝对值预处理、基准线设定、迪克逊准则引入、离群值等概念和算法,实现对异常绝对值的自动判断,进而判定基线值是否正确。

The Technical Rules for the Operation and Management of Geomagnetic Station Networks and the Measures for the Quality Evaluation of Electromagnetic Observation Data have no constraints or regulations on the selection of absolute observation baseline values for reference geomagnetic stations,which makes it difficult for observation personnel to rely on them when selecting baseline values,which can easily lead to errors in baseline values and affect absolute values.There are two constraint methods for selecting baseline values:①Direct constraint method(selected baseline value constraint),which involves baseline value preprocessing,temperature drift elimination,“2σ”criterion,and other methods to achieve constraints and judgments on the selected baseline values,with an effective judgment rate of over 60%;②Indirect constraint method(absolute value constraint),that is,through absolute value preprocessing,setting a baseline,introducing concepts and algorithms such as“Dixon criterion”and“outlier value”,to realize automatic judgment of abnormal absolute values and directly determine baseline values.This constraint method reduces the error rate of baseline values and improves data quality.