Traceable Radiometry Underpinning Terrestrial- & Helio- Studies James Aiken Plym Mar Lab Xavier Briottet ONERA John Barnett Ox univ. Steve Groom Plym Mar Lab Claus Frohlich WRC/PMOD Jo Haigh Imp Coll Olivier Hagolle CNES David Pollock U of Alab. Mike Sandford RAL Michael Schaepman U of Zur Werner Schmutz WRC/PMOD Keith Shine Uni of Read Phil Teillet CCRS Theo Theocharous NPL Kurtis Thome U of Ariz TRUTHS Nigel Fox NPL [email protected]