# Obtaining power over time with GNU radio

**URL:** <https://www.ruby-forum.com/t/obtaining-power-over-time-with-gnu-radio/251733>\
**Category:** GNU Radio\
**Created:** [January 24, 2019, 12:25pm UTC](https://www.ruby-forum.com/t/obtaining-power-over-time-with-gnu-radio/251733 "2019-01-24T12:25:37Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Dan889](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/7feea3/32.png) [@Dan889](https://www.ruby-forum.com/u/Dan889)\
**Post date:** [January 24, 2019, 12:25pm UTC](https://www.ruby-forum.com/t/obtaining-power-over-time-with-gnu-radio/251733/1 "2019-01-24T12:25:37Z")

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Hello,  
I recorded a signal to a file using a SDR device and GNUradio. The file is complex binary file.  
I would like to obtain from this file the power of the signal (in dBm) over time.  
How can I save this data using GNUradio, or MATLAB? I would like a log containing 2 columns, one of them is time from the file beginning, the other is the power at a certain frequency. Another possibility is to display the power at a certain frequency (in dBm) as a function of time on a graph.  
Appreciate the help.

Dan.