多次函数拟合法高精度转换传真天气图坐标  

High-precision Coordinate Conversion of Facsimile Weather Charts with Function Fitting Algorithm

作　　者：刘永禄[1] 

机构地区：[1]海军大连舰艇学院,辽宁大连116023

出　　处：《中国航海》2011年第2期81-85,共5页Navigation of China

基　　金：辽宁省自然科学基金资助项目(20082140)

摘　　要：在舰艇航行气象保障中,用到很多传真天气图资料,而且常常需要将传真天气图叠加在电子海图上,两者叠加的关键步骤之一是将传真天气图的图像坐标转换成经纬度坐标,由于常用的坐标转换计算方法误差通常在1°以上,叠加后天气信息在海图上的显示有较大偏差。为了提高坐标转换精度,提出多次函数拟合方法,在投影方程基础上,采用了结合多次函数拟合的数值来校正误差。计算后,经度平均误差±0.1°,纬度平均误差±0.2°。利用这个计算方法,可以比较准确地数字化传真天气图,能够应用于气象信息与地理信息系统融合以及舰船数值预报释用计算等领域。The facsimile weather charts are often used in meteorological supporting for naval ships.It is needed to make facsimile weather charts overlay on Electronic Chart Display System.One of the key points of doing this is that image coordinate is converted to geography coordinate.It is worth noting that the error of that calculation is usually more than 1°with common algorithms.In order to convert facsimile weather charts image coordinate into latitude and longitude coordinate,a high precision algorithm is proposed in this paper.Based on the projection functions,function fitting algorithm is used to calculate the error corrections for several times.The average latitude error can be decrease to ± 0.1 degrees and the average longitude error ± 0.2 degrees.Using this method,fax weather charts vectorization can be realized more accurately,which provides basic data for GIS and numerical weather forecast.

关 键 词：船舶、舰船工程 传真天气图 坐标转换 高精度 矢量化 信息 

分 类 号：U675.12[交通运输工程—船舶及航道工程]