地磁匹配导航中的特征区域选取

数字地磁图通常包括位置和场值信息，并以离散点形式存储，如何定量和全面地描述数字地图特征目前还没有统一标准。从数理统计和随机场理论出发，把标准差、粗糙度、熵和相关距离等概念应用到数字地磁图，作为度量地磁图特征的参数，研究了其在数字地图上的计算方法。在不同磁场区域经过多次匹配算法仿真，总结出地图特征区域选取的经验准则。在满足该选取准则的区域内地磁导航，匹配概率大于95％，匹配误差均值控制在0．3个单元网格内。可见，该特征区域选取准则满足一般的工程应用要求，可作为实际地磁导航的参考。

Selective criteria of characteristic area on geomagnetic map

The digital geomagnetic map usually includes the information of position and magnetic field,and is stored discretely. Since there's no consentaneous way to quantitatively and comprehensively describe the digital map's character at present,the paper,based on the mathematical statistics and the random field theory,applied the idea of variance,coarseness,entropy and relative distance into the digital map,and used them as the parameters to measure its character. Its computing method in digital map was also studied. The selective criteria of the digital map's characteristic area was given based on matching simulations in different geomagnetic filed. The simulation shows that the match probability was greater than 95%,and the error was less than 0.3 grid units. The criteria can be a reference in practice.