function Decoder(b, port) {
 var lat = (b[0] | b[1]<<8 | b[2]<<16 | (b[2] & 0x80 ? 0xFF<<24 : 0)) / 10000;
 var lon = (b[3] | b[4]<<8 | b[5]<<16 | (b[5] & 0x80 ? 0xFF<<24 : 0)) / 10000;
 var alt = (b[6] | b[7]<<8 | (b[7] & 0x80 ? 0xFF<<16 : 0));
 var hdop = b[8] / 100;
 return {
     latitude: lat,
     longitude: lon,
     altitude: alt,
     hdop: hdop
 };
}