Hi! How can I extract from the sp3data file just the lines that starts with the *. I need those days in matrix and after that to transform the dates in julian dates. I need the lines to be " 2011-04-19 0:00; 2011-04-19 0:15 and so on. Thank you

you can see what I obtain with this code:

fmt=['*' repmat('%f ',1,8)];
fid=fopen('sp3data.txt');
PG_timp=[];
while ~feof(fid)
  l=fgetl(fid);        % read a record
  if strfind(l,'*')
    PG_timp=[PG_timp; cell2mat(textscan(l,fmt,'collectoutput',1))];
  end
end
fid=fclose(fid);