www.pudn.com > easy8.rar > fepoch_0.m

function [time, dt, sats, eof, datee] = fepoch_0(fid) 
% FEPOCH_0   Finds the next epoch in an opened RINEX file with 
%	          identification fid. From the epoch line is produced 
%	          time (in seconds of week), number of sv.s, and a mark 
%	          about end of file. Only observations with epoch flag 0 
%	          are delt with. 
 
%Kai Borre 09-14-96; revised 03-22-97; revised Sept 4, 2001 
%Copyright (c) by Kai Borre 
%$Revision: 1.0 $  $Date: 1997/09/22  $ 
%fide = fopen(fid,'rt'); 
 
global sat_index; 
time = 0; 
dt = 0; 
sats = [];
NoSv = 0; 
eof = 0; 
 
while 1 
   lin = fgets(fid); % earlier fgetl 
   answer = findstr(lin,'COMMENT');
    
   if ~isempty(answer); 
      lin = fgetl(fid); 
   end;
  
    
   if (feof(fid) == 1); 
      eof = 1; 
      break 
   end; 
   if ((strcmp(lin(29),'0') == 0) & (size(deblank(lin),2) == 29)) 
      eof = 1;  
      break 
   end; % We only want type 0 data 
   if ((strcmp(lin(2),'0') == 1)  &  (strcmp(lin(29),'0') == 1))       
      ll = length(lin)-2; 
      if ll > 60, ll = 60; end; 
      linp = lin(1:ll);         
      %fprintf('%60s\n',linp); 
      [year, lin] = strtok(lin);
      year; 
      [month, lin] = strtok(lin); 
      [day, lin] = strtok(lin);
      month;
      day; 
      [hour, lin] = strtok(lin);
      %hour 
      [minute, lin] = strtok(lin);
      %minute 
      [second, lin] = strtok(lin);
      %second 
      [OK_flag, lin] = strtok(lin); 
      h = str2num(hour)+str2num(minute)/60+str2num(second)/3600; 
      jd = julday(str2num(year)+2000, str2num(month), str2num(day), h); 
      [week, sec_of_week] = gps_time(jd);
      jd; 
      time = sec_of_week; 
      [NoSv, lin] = strtok(lin,'G');
      
      for k = 1:str2num(NoSv) 
         [sat, lin] = strtok(lin,'G'); 
         prn(k) = str2num(sat); 
      end
       
      sats = prn(:); 
      dT = strtok(lin); 
      if isempty(dT) == 0 
         dt = str2num(dT); 
      end 
      break
       
   end
    
end;  
datee=[str2num(year) str2num(month) str2num(day) str2num(hour) str2num(minute) str2num(second)]; 
 
%%%%%%%% end fepoch_0.m %%%%%%%%%