期刊名称：International Journal of Computer Science and Network
印刷版ISSN：2277-5420
出版年度：2012
卷号：1
期号：4
出版社：IJCSN publisher
摘要：Methods for measuring the distance to some objects canbe divided into active and passive ones. The activemethods are measuring the distance by sending somesignals to the object (e.g. laser beam, radio signals, ultrasound,etc.) while passive ones only receive informationabout object’s position (usually by light).
