56 lines
2.3 KiB
Mathematica
56 lines
2.3 KiB
Mathematica
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%Gen ephemeris message for every satellite
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%function InitCodePhase=GenerateSatellitesPseudoranges(InitObsTime,DurationTime,LLH,PRNlist,ElevationMask)
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clear workspace
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addpath ..\include % The software receiver functions
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addpath ..\geoFunctions % Position calculation related functions
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addpath ..
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load trackingResults_HN.mat
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%fidASCII=fopen('..\..\..\works\EstimatingCN0\GNSS_SIM\NAV3\nav_test','rt');
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fidASCII=fopen('..\..\..\works\EstimatingCN0\GNSS_SIM\Ephemeris\nav02','rt');
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%fidASCII=fopen('..\..\..\works\EstimatingCN0\GNSS_SIM\NAV3\navascii2','rt');
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data=fread(fidASCII,'char')-48;
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data(data==0)=-1;
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data=data(532:end)';
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clear trackResults;
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trackResults(1).I_P=kron(data,ones(1,20));
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%trackResults(1).I_P=trackResults(1).I_P(15000*20:end);
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trackResults(2:end)=[];
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trackResults(1).status='T';
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[subFrameStart, activeChnList] = findPreambles2(trackResults, settings);
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LLH=[21.004498873852768 105.8435979060256 50.956094086170197];
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PRNlist=[3 6 13 16 19 23];
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ElevationMask=10;
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for channelNr = activeChnList
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%=== Convert tracking output to navigation bits =======================
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%--- Copy 5 sub-frames long record from tracking output ---------------
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navBitsSamples = trackResults(channelNr).I_P(subFrameStart(channelNr) - 20 : ...
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subFrameStart(channelNr) + (1500 * 20) -1)';
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%--- Group every 20 vales of bits into columns ------------------------
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navBitsSamples = reshape(navBitsSamples, ...
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20, (size(navBitsSamples, 1) / 20));
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%--- Sum all samples in the bits to get the best estimate -------------
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navBits = sum(navBitsSamples);
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%--- Now threshold and make 1 and 0 -----------------------------------
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% The expression (navBits > 0) returns an array with elements set to 1
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% if the condition is met and set to 0 if it is not met.
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navBits = (navBits > 0);
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%--- Convert from decimal to binary -----------------------------------
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% The function ephemeris expects input in binary form. In Matlab it is
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% a string array containing only "0" and "1" characters.
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navBitsBin = dec2bin(navBits);
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%=== Decode ephemerides and TOW of the first sub-frame ================
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[eph(trackResults(channelNr).PRN), TOW] = ...
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ephemeris(navBitsBin(2:1501)', navBitsBin(1));
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end
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