what is Radar deducting?

no such thing. But there is radar ducting. radar signal gets trapped in a layer between ground and maybe 30' altitude.


http://www.df5ai.net/ArticlesDL/VK3KAQDucts2007V3.5.pdf

thanks a lot biff44.but I want to know is way to Confronting with duct phenomenon?

sure, just in any multipath situation, u have to use processing to combine multiple inputs that are all the same thing, but multipathed

that's very usefull to me....thanks.....i need some details are u can introduce me book , related paper or investigation about this.thanks again