%function InitCodePhase=GenerateSatellitesPseudoranges(InitObsTime,DurationTime,LLH,PRNlist,ElevationMask)
clear all
addpath ..\include             % The software receiver functions
addpath ..\geoFunctions        % Position calculation related functions
addpath ..

load trackingResults_HN.mat
%navSolutions = postNavigation(trackResults, settings);
%pseudorange=navSolutions.channel.rawP;

%Gen ephemeris message for every satellite
[subFrameStart, activeChnList] = findPreambles(trackResults, settings);

LLH=[21.004498873852768  105.8435979060256 50.956094086170197];
PRNlist=[3 6 13 16 19 23];
ElevationMask=10;
for channelNr = activeChnList

    %=== Convert tracking output to navigation bits =======================

    %--- Copy 5 sub-frames long record from tracking output ---------------
    navBitsSamples = trackResults(channelNr).I_P(subFrameStart(channelNr) - 20 : ...
                               subFrameStart(channelNr) + (1500 * 20) -1)';

    %--- Group every 20 vales of bits into columns ------------------------
    navBitsSamples = reshape(navBitsSamples, ...
                             20, (size(navBitsSamples, 1) / 20));

    %--- Sum all samples in the bits to get the best estimate -------------
    navBits = sum(navBitsSamples);

    %--- Now threshold and make 1 and 0 -----------------------------------
    % The expression (navBits > 0) returns an array with elements set to 1
    % if the condition is met and set to 0 if it is not met.
    navBits = (navBits > 0);

    %--- Convert from decimal to binary -----------------------------------
    % The function ephemeris expects input in binary form. In Matlab it is
    % a string array containing only "0" and "1" characters.
    navBitsBin = dec2bin(navBits);
    
    %=== Decode ephemerides and TOW of the first sub-frame ================
    [eph(trackResults(channelNr).PRN), TOW] = ...
                            ephemeris(navBitsBin(2:1501)', navBitsBin(1));
end
[tmpx tmpy tmpz]=llh2xyz(LLH(1),LLH(2),LLH(3));
userxyz=[tmpx tmpy tmpz];
InitObsTime=TOW;
DurationTime=360;
obsTime=[InitObsTime:0.001:InitObsTime+DurationTime+1];
speedOfLight=299792458;
lengthOfChips=speedOfLight/1.023e6;
idxTTime=1;
hwb=waitbar(0,'Please wait');
distByChips=zeros(length(obsTime),length(PRNlist));

for transmitTime=obsTime
    if rem(idxTTime,10)==0 
        waitbar((transmitTime-obsTime(1))/(obsTime(end)-obsTime(1)),hwb);
    end;
    validPRN=[];
    for PRN=PRNlist;
        if PRN==24
            continue;
        end;
        [satPosition, satClkCorr] = satpos(transmitTime, ...
                                                PRN, ...
                                                eph);

        [az, el, tmpDist] = topocent(userxyz', satPosition - userxyz');
        dist=tmpDist-satClkCorr*speedOfLight;
        distByChips(idxTTime,PRN)=dist/lengthOfChips;
        if (el>=ElevationMask)&& (el<=90)
           validPRN=[validPRN PRN];
        end;
    end;
    idxTTime=idxTTime+1;
end;
InitCodePhase=distByChips(:,validPRN);
close(hwb);
save InitCodePhase InitCodePhase