http://xmm.esac.esa.int/docs/documents/CAL-SRN-0261-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0250-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0229-1-1.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0217-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0179-1-1.ps.gz