gr_plot_const - constellation plot of I&Q data using GNU Radio
gr_plot_const: [options] input_filename
Takes a GNU Radio complex binary file and displays the I&Q data versus time and the constellation plot (I vs. Q). You can set the block size to specify how many points to read in at a time and the start position in the file. By default, the system assumes a sample rate of 1, so in time, each sample is plotted versus the sample number. To set a true time axis, set the sample rate (-R or --sample-rate) to the sample rate used when capturing the samples.