夜间电离层频高曲线的一种新的换算方法

本方法的关键在于建立对最小可见频率f_min以上包括九至十五个视高h′数据的同步换算范围进行精确可靠的换算方法。对同步换算范围给出三个各包含二个未知数的高层模式,对f_min以下给出六或八个各包含二个未知数的低层模式。按照最小二乘法对每一条频高曲线最多可以得到二十个各不相同的换算结果。通过一定的方法可以从中挑选出精确的结果。对468条其形状、临界频率f_c、半厚H以及f_min各不相同的其精度为0.1公里左右的理论夜间频高曲线进行了换算。其中462条曲线的极大换算误差不超过5公里,6条曲线介于5公里至9公里之间。

A NEW REDUCTION METHOD FOR NOCTURNAL IONOSPHERIC h'-f CURVES

The purpose of this paper is to find an accurate and reliable reduction method for the synchro-reduction domain including nine to fifteen virtual height data above the minimal appreciable frequency f_min. For this domain three higher ionization mo-dels with two variables are given, whereas six or eight lower ionization models with two variables are given for the ionization below f_min. At most twenty different reduc-tion results may be obtained for each h'-f curve by the least square method. It is possible to select an accurate result from the above calculations. 468 theoretical noc-turnal h'-f curves have been reduced. They possess different shapes, critical fre-quencies f_c, semi-thicknesses H and f_min's, and these theoretical virtual heights have an accuracy of about 0.1 km. The maximal reduction errors of 462 h'-f curves are less than 5 km, whereas those of 6 curves are between 5-9 km.