final Rational precisionRational = gpsDirectory.getRational(GpsDirectory.TAG_GPS_DOP);
precision = (precisionRational == null) ? null : precisionRational.floatValue();
gpsDatestamp = gpsDirectory.getString(GpsDirectory.TAG_GPS_DATE_STAMP);
final GpsDescriptor gpsDescriptor = new GpsDescriptor(gpsDirectory);
gpsTimestamp = gpsDescriptor.getGpsTimeStampDescription();
}