function [Obs_types, ant_delta,ifound_types,eof] = anheader(file)
%ANHEADER Analyzes the header of a RINEX file and outputs
%	       the list of observation types and antenna offset.
%	       End of file is flagged 1, else 0. Likewise for the types.
%	       Typical call: anheader('pta.96o')

%Kai Borre 09-12-96
%Copyright (c) by Kai Borre
%$Revision: 1.0 $   $Date: 1997/09/23  $

fid = fopen(file,'rt');
eof = 0;
ifound_types = 0;
Obs_types = [];
ant_delta = [];

while 1			   % Gobbling the header
   line = fgetl(fid);
   answer = findstr(line,'END OF HEADER');
   if  ~isempty(answer), break; end;
   if (line == -1), eof = 1; break; end;
   answer = findstr(line,'ANTENNA: DELTA H/E/N');
   if ~isempty(answer)
      for k = 1:3
         [delta, line] = strtok(line);
         del = str2num(delta);
         ant_delta = [ant_delta del];
      end;
   end
   answer = findstr(line,'# / TYPES OF OBSERV');
   if ~isempty(answer)
      [NObs, line] = strtok(line);
      NoObs = str2num(NObs);
      for k = 1:NoObs
         [ot, line] = strtok(line);
         Obs_types = [Obs_types ot];
      end;
      ifound_types = 1;
   end;
end;

%fclose(fid);
%%%%%%%%% end anheader.m %%%%%%%%%