thanks for your response,but i run the rtl_power in android and want to display the frequency specturm in android too. so maybe matlab scanner is not fit,anyway, thanks all the same ------------------ 原始邮件 ------------------ 发件人: "Jiao Xianjun";<putaoshu(a)gmail.com>ail.com>; 发送时间: 2014年1月26日(星期天) 晚上6:25 收件人: ""<393775602(a)qq.com>75602@qq.com>; 抄送: "osmocom-sdr"<osmocom-sdr(a)lists.osmocom.org>.osmocom.org>; 主题: Re: how to get a certain frequency spectrum using rtl_power If you are familiar with matlab, maybe you can try my matlab scanner. It is easy to change frequency range, RBW, etc, and get spectrum picture. Please google: " rtl sdr matlab scanner" Good luck! 393775602 <393775602(a)qq.com> wrote: Hi, i am doing a project to get a certain fequencyspectrum . And thanks to the wonderful tool rtl_power, i can get some dbm data over a very wide area of the frequency specturm. and i read the source code in order to change it to get a certain frequency specturm.Sadly, i know little about digital signal processiong and getting a hard time solving it. does anyone know how to get a certain fequencyspectrum using rtl_power or some other tool. sincerely Chen Zujie