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Dtacq2weraNew

  % dtacq2wera chirp-by-chirp

  NCHAN=16;                       % number of dtacq A/D channel pairs
  IQ=2;                           % number of channels to make a pair
  OVER=2;                         % dtacq oversampling rate
  NANT=16;                                % WERA number of antennas
  MT=1984;                        % number of WERA samples per chirp
  NCHIRP=2048;                    % number of chirps
  SKIP=1;                         % number of chirps skipped
  FIRSKIP=28;                     % number of samples skipped before first chirp due to FIR transcient
  SHIFT=7;                        % number of bits lost when converting 32->16 bits
  HEADTAG='2048 SAMPLES   ';      % part of the header necessary

  fi=fopen(filein,'r','ieee-le');

  fseek(fi,0,'eof');
  pos=ftell(fi);

  % check file size is big enough to skip FIR transcient and first chirp, plus
  % still contain 2048 chirps
  if pos<((NCHAN*IQ*OVER*MT*(NCHIRP+SKIP))+(FIRSKIP*NCHAN*IQ))*4
      error('File size incorrect: Input file too small')

  else
      % move to after FIR transcient and first chirp
      clear pos
      fseek(fi,((FIRSKIP*NCHAN*IQ)+(SKIP*NCHAN*IQ*OVER*MT))*4,'bof');

      % make channel map; first column is dta channel, second is WERA
      % antenna, third is IQ (1 for I, 2 for Q)
      % for swapped I and Q cables
      map=reshape([ 1 1 2 2 5 2 3 1 1 4 5 1 5 2 2 6 6 2 7 2 1 8 6 1 9 3 2 10 ...
          7 2 11 3 1 12 7 1 13 4 2 14 8 2 15 4 1 16 8 1 17 13 1 18 9 1 19 13 ...
          2 20 9 2 21 14 1 22 10 1 23 14 2 24 10 2 25 15 1 26 11 1 27 15 2 28 ...
          11 2 29 16 1 30 12 1 31 16 2 32 12 2],3,32)';

      % for normal I and Q cables
      map=reshape([ 1 1 1 2 5 1 3 1 2 4 5 2 5 2 1 6 6 1 7 2 2 8 6 2 9 3 1 10 ...
        7 1 11 3 2 12 7 2 13 4 1 14 8 1 15 4 2 16 8 2 17 13 2 18 9 2 19 13 ...
        1 20 9 1 21 14 2 22 10 2 23 14 1 24 10 1 25 15 2 26 11 2 27 15 1 28 ...
        11 1 29 16 2 30 12 2 31 16 1 32 12 1],3,32)';

      % get time of acquisition for header
      ft=fopen(filetime,'r','ieee-le');
      timed=fread(ft,inf,'*char');
      fclose(ft);

      % get WERA header
      fh=fopen(filehead,'r','ieee-le');
      header=fread(fh,inf,'*char');
      fclose(fh);
      clear ft fh

      % write header to output file
      fo=fopen(fileout,'w','ieee-le');
      fwrite(fo,[HEADTAG timed' header'],'*char');
      clear header timed

      % loop over all chirps
      wera=int16(zeros(IQ,MT,NANT,NCHIRP));
      for ichirp=1:NCHIRP
          data=fread(fi,[NCHAN*IQ,OVER*MT],'int32=>int32');

          % average oversampling, get rid of SHIFT bits, and move to 16-bit
          % reorder channels to WERA standard
          sdata=int16(zeros(NCHAN*IQ,MT));
          wera1=int16(zeros(IQ,MT,NANT));
          for ichan=1:NANT*IQ
              sdata(ichan,1:MT)=int16((data(ichan,1:OVER:OVER*MT-1) ...
                  + data(ichan,2:OVER:OVER*MT))/2^(SHIFT+1));
              wera1(IQ-map(ichan,3)+1,:,map(ichan,2))=sdata(ichan,:);
          end
          clear data ichan
          %wera(:,:,:,ichirp)=wera1;
          % write data chirp-by-chirp
          fwrite(fo,wera1,'int16');

      end
      clear ichirp map
      fclose(fo);

  end

  fclose(fi);
  clear fi fo
  save(filemat)