el_and_masked_sigmaphi.m

function [tlim, splim, s4lim] = el_and_masked_sigmaphi(cases_folder, home_dir, rcvr_op, doy, year, signal, spmask, s4mask)
sep = filesep;

%% Plot elevation and elevation-filtered sigmaphi prn by prn for all receivers
SPM = [];
S4M = [];
for kk = 1:32
    if kk <= 16
        fig1 = subplot(8, 2, kk);
    elseif kk == 17
        figure;
        subplot(8, 2, kk-16);
    else
        fig2 = subplot(8, 2, kk-16);
    end
    
    legend_count = 0;
    for rr = 1:size(rcvr_op, 1)
        rcvr_name = rcvr_op(rr, :);
        [color] = rx_color(rcvr_name);
        scintout = strcat('prn_files_', signal, sep, 'scintdata.mat');
        elout = strcat('prn_files_', signal, sep, 'txinfodata.mat');
        %         if strcmp(case_folder(end-4:end-1),'pfrr')
        %             %folder_path for 2013 Poker Flat data
        %             op_path = strcat([home_dir,'PFRR_Data/',rcvr_name,sep,year,sep,doy,sep]);
        %         else
        %             %folder_path for 2013 Calgary data
        %             op_path = strcat([home_dir,'Calgary_Data/',rcvr_name,sep,doy,sep]);
        %         end
        [~, op_path] = inoutpath(cases_folder, home_dir, year, doy, rcvr_name);
        %load scintdata & txinfodata
        load([op_path, scintout]);
        load([op_path, elout]);
        if ~isempty(DATA)
            datestt = gps2utc(DATA(1, 1:2));
            dateend = gps2utc(DATA(end, 1:2));
        elseif ~isempty(DATA_el)
            datestt = gps2utc(DATA_el(1, 1:2));
            dateend = gps2utc(DATA_el(end, 1:2));
        else
            datestt = [];
            dateend = [];
        end
        %         tlim = find_tlim(datestt,dateend,doy);
        tlim = datenum([datestt; dateend])';
        %plot elevation w/o 30deg mask
        dt = 1 / 24 / 3600 * 600;
        if ~isempty(DATA_el)
            plot_el(DATA_el, kk, dt, color, tlim);
            legend_count = legend_count + 1;
            RCVRNAME{legend_count, :} = [rcvr_name, ' el'];
        end
        if ~isempty(DATA) && ~isempty(DATA_el)
            elmask = 30;
            [spm{rr}, s4m{rr}] = plot_masked_sigmaphi(DATA, DATA_el, kk, dt, elmask, color, tlim);
            legend_count = legend_count + 1;
            RCVRNAME{legend_count, :} = [rcvr_name, ' \sigma_\phi'];
        else
            spm{rr} = [];
            s4m{rr} = [];
        end
    end
    if kk == 32 || kk == 16
        %         legend(RCVRNAME);
        ylabel('el [deg], $\sigma_\phi$ [cycle]')
    end
    SPM = [SPM; spm];
    S4M = [S4M; s4m];
end

%% Save elevation-filtered and elevation & sp mask filtered scintillation data
MAXSP = [];
MAXS4 = [];
for rr = 1:size(SPM, 2)
    rcvr_name = rcvr_op(rr, :);
    SPM_M = [];
    S4M_M = [];
    for kk = 1:size(SPM, 1)
        SPM_M = [SPM_M; SPM{kk, rr}];
        S4M_M = [S4M_M; S4M{kk, rr}];
    end
    %unit conversion from cycles to radians for sigmaphi values
    if ~isempty(SPM_M)
        SPM_M(:, 2) = SPM_M(:, 2) * 2 * pi;
        maxsp = max(SPM_M(:, 2));
        maxs4 = max(S4M_M(:, 2));
    else
        maxsp = 0;
        maxs4 = 0;
    end
    MAXSP = [MAXSP; maxsp];
    MAXS4 = [MAXS4; maxs4];
    SPM_elm = SPM_M;
    SP4_elm = S4M_M;
    %     if strcmp(case_folder(end-4:end-1),'pfrr')
    %         %folder_path for 2013 Poker Flat data
    %         op_path = strcat([home_dir,'PFRR_Data/',rcvr_name,sep,year,sep,doy,sep]);
    %     else
    %         %folder_path for 2013 Calgary data
    %         op_path = strcat([home_dir,'Calgary_Data/',rcvr_name,sep,doy,sep]);
    %     end
    [~, op_path] = inoutpath(cases_folder, home_dir, year, doy, rcvr_name);
    outfilename = strcat('prn_files_', signal, sep, 'spdata.mat');
    save([op_path, outfilename], 'SPM_elm', 'SP4_elm');
    %further eliminate lower sigmaphi values with sigmaphi mask
    if ~isempty(SPM_M)
        SPM_M = SPM_M(SPM_M(:, 2) > spmask, :);
        S4M_M = S4M_M(S4M_M(:, 2) > s4mask, :);
    else
        SPM_M = [];
        S4M_M = [];
    end
    outfilename = strcat('prn_files_', signal, sep, 'fltrdata.mat');
    save([op_path, outfilename], 'SPM_M', 'S4M_M');
end

MAXSP
MAXS4
splim = max(MAXSP);
s4lim = max(MAXS4);
fig_name = strcat(signal, '_LowRateSigmaPhiWithElevationMask_');
fig_1 = strcat(op_path, fig_name, '_fig1', '.eps');
fig_2 = strcat(op_path, fig_name, '_fig2', '.eps');
saveas(fig1, fig_1, 'epsc2');
saveas(fig2, fig_2, 'epsc2');