diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java b/brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java
new file mode 100644
index 0000000..0866c7d
--- /dev/null
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java
@@ -0,0 +1,220 @@
+package btools.mapcreator;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.DataInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+public class ConvertLidarTile
+{
+  public static int NROWS;
+  public static int NCOLS;
+
+  public static final short NODATA2 = -32767; // hgt-formats nodata
+  public static final short NODATA = Short.MIN_VALUE;
+
+  static short[] imagePixels;
+
+  private static void readHgtZip( String filename, int rowOffset, int colOffset ) throws Exception
+  {
+    ZipInputStream zis = new ZipInputStream( new BufferedInputStream( new FileInputStream( filename ) ) );
+    try
+    {
+      for ( ;; )
+      {
+        ZipEntry ze = zis.getNextEntry();
+        if ( ze.getName().endsWith( ".hgt" ) )
+        {
+          readHgtFromStream( zis, rowOffset, colOffset );
+          return;
+        }
+      }
+    }
+    finally
+    {
+      zis.close();
+    }
+  }
+
+  private static void readHgtFromStream( InputStream is, int rowOffset, int colOffset )
+      throws Exception
+  {
+    DataInputStream dis = new DataInputStream( new BufferedInputStream( is ) );
+    for ( int ir = 0; ir < 1201; ir++ )
+    {
+      int row = rowOffset + ir;
+
+      for ( int ic = 0; ic < 1201; ic++ )
+      {
+        int col = colOffset + ic;
+
+        int i1 = dis.read(); // msb first!
+        int i0 = dis.read();
+
+        if ( i0 == -1 || i1 == -1 )
+          throw new RuntimeException( "unexcepted end of file reading hgt entry!" );
+
+        short val = (short) ( ( i1 << 8 ) | i0 );
+
+        if ( val == NODATA2 )
+        {
+          val = NODATA;
+        }
+
+        setPixel( row, col, val );
+      }
+    }
+  }
+
+
+  private static void setPixel( int row, int col, short val )
+  {
+    if ( row >= 0 && row < NROWS && col >= 0 && col < NCOLS )
+    {
+      imagePixels[row * NCOLS + col] = val;
+    }
+  }
+
+  private static short getPixel( int row, int col )
+  {
+    if ( row >= 0 && row < NROWS && col >= 0 && col < NCOLS )
+    {
+      return imagePixels[row * NCOLS + col];
+    }
+    return NODATA;
+  }
+
+
+  public static void doConvert( String inputDir, int lonDegreeStart, int latDegreeStart, String outputFile ) throws Exception
+  {
+    int extraBorder = 0;
+
+    NROWS = 5 * 1200 + 1 + 2 * extraBorder;
+    NCOLS = 5 * 1200 + 1 + 2 * extraBorder;
+
+    imagePixels = new short[NROWS * NCOLS]; // 650 MB !
+
+    // prefill as NODATA
+    for ( int row = 0; row < NROWS; row++ )
+    {
+      for ( int col = 0; col < NCOLS; col++ )
+      {
+        imagePixels[row * NCOLS + col] = NODATA;
+      }
+    }
+
+    for ( int latIdx = -1; latIdx <= 5; latIdx++ )
+    {
+      int latDegree = latDegreeStart + latIdx;
+      int rowOffset = extraBorder + ( 4 - latIdx ) * 1200;
+
+      for ( int lonIdx = -1; lonIdx <= 5; lonIdx++ )
+      {
+        int lonDegree = lonDegreeStart + lonIdx;
+        int colOffset = extraBorder + lonIdx * 1200;
+
+        String filename = inputDir + "/" + formatLat( latDegree ) + formatLon( lonDegree ) + ".zip";
+        File f = new File( filename );
+        if ( f.exists() && f.length() > 0 )
+        {
+          System.out.println( "exist: " + filename );
+          readHgtZip( filename, rowOffset, colOffset );
+        }
+        else
+        {
+          System.out.println( "none : " + filename );
+        }
+      }
+    }
+
+    boolean halfCol5 = false; // no halfcol tiles in lidar data (?)
+
+
+    SrtmRaster raster = new SrtmRaster();
+    raster.nrows = NROWS;
+    raster.ncols = NCOLS;
+    raster.halfcol = halfCol5;
+    raster.noDataValue = NODATA;
+    raster.cellsize = 1 / 1200.;
+    raster.xllcorner = lonDegreeStart - ( 0.5 + extraBorder ) * raster.cellsize;
+    raster.yllcorner = latDegreeStart - ( 0.5 + extraBorder ) * raster.cellsize;
+    raster.eval_array = imagePixels;
+
+    // encode the raster
+    OutputStream os = new BufferedOutputStream( new FileOutputStream( outputFile ) );
+    new RasterCoder().encodeRaster( raster, os );
+    os.close();
+
+    // decode the raster
+    InputStream is = new BufferedInputStream( new FileInputStream( outputFile ) );
+    SrtmRaster raster2 = new RasterCoder().decodeRaster( is );
+    is.close();
+
+    short[] pix2 = raster2.eval_array;
+    if ( pix2.length != imagePixels.length )
+      throw new RuntimeException( "length mismatch!" );
+
+    // compare decoding result
+    for ( int row = 0; row < NROWS; row++ )
+    {
+      int colstep = halfCol5 ? 2 : 1;
+      for ( int col = 0; col < NCOLS; col += colstep )
+      {
+        int idx = row * NCOLS + col;
+        short p2 = pix2[idx];
+        if ( p2 != imagePixels[idx] )
+        {
+          throw new RuntimeException( "content mismatch: p2=" + p2 + " p1=" + imagePixels[idx] );
+        }
+      }
+    }
+  }
+
+  private static String formatLon( int lon )
+  {
+    if ( lon >= 180 )
+      lon -= 180; // TODO: w180 oder E180 ?
+
+    String s = "E";
+    if ( lon < 0 )
+    {
+      lon = -lon;
+      s = "E";
+    }
+    String n = "000" + lon;
+    return s + n.substring( n.length() - 3 );
+  }
+
+  private static String formatLat( int lat )
+  {
+    String s = "N";
+    if ( lat < 0 )
+    {
+      lat = -lat;
+      s = "S";
+    }
+    String n = "00" + lat;
+    return s + n.substring( n.length() - 2 );
+  }
+
+  public static void main( String[] args ) throws Exception
+  {
+      String filename90 = args[0];
+      String filename30 = filename90.substring( 0, filename90.length() - 3 ) + "bef";
+
+      int srtmLonIdx = Integer.parseInt( filename90.substring( 5, 7 ).toLowerCase() );
+      int srtmLatIdx = Integer.parseInt( filename90.substring( 8, 10 ).toLowerCase() );
+
+      int ilon_base = ( srtmLonIdx - 1 ) * 5 - 180;
+      int ilat_base = 150 - srtmLatIdx * 5 - 90;
+      
+      doConvert( args[1], ilon_base, ilat_base, filename30 );
+  }
+  
+}