摘要
数字水准仪的标尺编码规则直接影响其测量精度。基于现有几种数字水准仪标尺编码的特点,归纳出标尺条码的编码衡量指标:信息密度、分辨率和纠错能力。以条码的最大编码容量与单个码区长度之比值衡量其承载的信息密度;利用光学系统的点扩散函数研究条码图像的分辨率,即相邻边缘的相互影响,得出码元相邻边缘的间距相等时,影响最小的结论;用相关系数或编码所用函数本身的性质表征条码的纠错能力。依据编码指标建立一套新的标尺编码规则:以格雷码为数值码,固定宽度的码元为参考码,两者交替组合。分析表明,该种编码不但信息密度大,分辨率高,而且纠错能力强。
The rule of coded level ruler affected the measurement precision directly in digital level, The guidelines of the coded level ruler nowadays included with information density, resolution and correction ability. The information density is showed by the ratio of maximal information content and unit code area length. The resolution is researched based on point spread function of optical system. The interaction influence of immedi ate code edge is the least when the space of code edge was equal. Correction ability is showed with correlative coefficient or inwardness of functions used in encoding, A new encoding is presented according to the above rule： it comprised numerical code expressed with Gray and referenced code expressed with a settled breadth that combined alternately. The encoding has many virtues such as large information density, high resolution and great correction ability.
出处
《测绘学报》
EI
CSCD
北大核心
2008年第3期380-383,共4页
Acta Geodaetica et Cartographica Sinica
关键词
数字水准仪
标尺编码
信息密度
分辨率
纠错能力
digital level
level ruler encoding
information density
resolution
correction ability
