grib/src/main/java/ucar/nc2/grib/grib1/Grib1SectionProductDefinition.java
public boolean isEnsemble() {
    switch (getCenter()) {
      case 7:
        return ((rawData.length >= 43) && (getOctet(41) == 1));

      case 98:
        return ((rawData.length >= 51) &&
                (getOctet(41) == 1 || getOctet(41) == 30) &&
                (getOctet(43) == 10 || getOctet(43) == 11));
    }
    return false;
  }
public boolean isEnsemble() {
    switch (getCenter()) {
      case 7:
        return ((rawData.length >= 43) && (getOctet(41) == 1));

      case 98:
        return ((rawData.length >= 51) &&
                (getOctet(41) == 1 || getOctet(41) == 30) &&
                (getOctet(43) == 10 || getOctet(43) == 11));
    }
    return false;
  }
/*
NCEP Appendix C Manual 388
http://www.nco.ncep.noaa.gov/pmb/docs/on388/appendixc.html
states that if the PDS is > 28 bytes and octet 41 == 1
then it's an ensemble an product.