% Reads GNSS-SDR Acquisition dump binary file using the provided % function and plots acquisition grid of acquisition statistic of PRN sat % % This function analyzes a experiment performed by Luis Esteve in the framework % of the Google Summer of Code (GSoC) 2012, with the collaboration of Javier Arribas % and Carles Fernandez, related to the extension of GNSS-SDR to Galileo. % % ------------------------------------------------------------------------- % % Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors) % % GNSS-SDR is a software defined Global Navigation % Satellite Systems receiver % % This file is part of GNSS-SDR. % % SPDX-License-Identifier: GPL-3.0-or-later % % ------------------------------------------------------------------------- % function plot_acq_grid_gsoc_glonass(sat) file=['/archive/acquisition_R_1G_sat_' num2str(sat) '_doppler_0.dat']; % sampling_freq_Hz=62316000 sampling_freq_Hz=6.625e6 Doppler_max_Hz = 10000 Doppler_min_Hz = -10000 Doppler_step_Hz = 250 % read files x=read_complex_binary (file); l_y=length(x); Doppler_axes=Doppler_min_Hz:Doppler_step_Hz:Doppler_max_Hz; l_x=length(Doppler_axes); acq_grid = zeros(l_x,l_y); index=0; for k=Doppler_min_Hz:Doppler_step_Hz:Doppler_max_Hz index=index+1; filename=['acquisition_R_1G_sat_' num2str(sat) '_doppler_' num2str(k) '.dat']; acq_grid(index,:)=abs(read_complex_binary (filename)); end acq_grid = acq_grid.^2; maximum_correlation_peak = max(max(acq_grid)) [fila,col]=find(acq_grid==max(max(acq_grid))); delay_error_sps = col -1 Doppler_error_Hz = Doppler_axes(fila) noise_grid=acq_grid; delay_span=floor(3*sampling_freq_Hz/(0.511e6)); Doppler_span=floor(500/Doppler_step_Hz); noise_grid(fila-Doppler_span:fila+Doppler_span,col-delay_span:col+delay_span)=0; n=numel(noise_grid)-(2*delay_span+1)*(2*Doppler_span+1); noise_floor= sum(sum(noise_grid))/n Gain_dbs = 10*log10(maximum_correlation_peak/noise_floor) %% Plot 3D FULL RESOLUTION [X,Y] = meshgrid(Doppler_axes,1:1:l_y); figure; surf(X,Y,acq_grid'); xlabel('Doppler(Hz)');ylabel('Code Delay(samples)');title(['GLRT statistic of Glonass Parallel Code Phase Search Acquisition. Local replica: L1 cboc PRN ' num2str(sat)]); end