Create STK Ephemeris File from MATLAB

How to use:

In MATLAB, call the function and input your data file (sample data file attached).

>> Create_STK_EphemerisFile('C:\Users\<username>\Desktop\Sample_LLA_Data.txt')
 

function [ ] = Create_STK_EphemerisFile( filepath )

    fileID = fopen(filepath);
    C = textscan(fileID,'%s %s %s %s');
    fclose(fileID);

    Time = C{1};
    Lat = C{2};
    Lon = C{3};
    Alt = C{4};

    eFilePath = [pwd '\outputEphemeris.e'];

    dataPts = length(Time);

    eData = cell(dataPts,4); %Define dimensions of 'eData' cell array
    %Create Time, Lat, Lon, Alt columns to send to e file
    for i = 1:dataPts   
        eData{i,1} = Time{i}; 
        eData{i,2} = Lat{i};
        eData{i,3} = Lon{i};
        eData{i,4} = Alt{i};
    end

    %%%%---------- Create ephemeris file (*.e) ----------%%%%
    eFile = fopen(eFilePath, 'wt', 'n', 'US-ASCII');

    %Write ephemeris file headers
    fprintf(eFile,'stk.v.10.0\n');
    fprintf(eFile,'BEGIN Ephemeris\n');
    fprintf(eFile,['NumberOfEphemerisPoints   ' num2str(dataPts) '\n']);
    fprintf(eFile,'InterpolationMethod     GreatArcMSL\n');
    fprintf(eFile,'InterpolationOrder 1\n');
    fprintf(eFile,'CentralBody             	Earth\n');
    fprintf(eFile,'DistanceUnit Feet\n');
    fprintf(eFile,'ScenarioEpoch 9 Oct 2015 16:00:00.000\n');
    fprintf(eFile,'TimeFormat        EpSec\n');
    fprintf(eFile,'EphemerisMSLLLATimePos\n');
    
    %Add Time, Lat, Lon, Alt Columns to the file
    formatSpec = '%s %s %s %s\n';
    for row = 1:dataPts
        fprintf(eFile,formatSpec,eData{row,:});
    end

    fprintf(eFile,'END Ephemeris\n');
    
    %Close and confirm the creation of the new file
    fclose(eFile);