Produit altimétrique Envisat de niveau 2 GDR (monomission, le long de la trace)
GDR L2 from ESA Baseline-C converted by CTOH into netCDF, splited by ascending/descending pass and augmented of recent corrections.
Both successive orbits are proposed:
Envisat V2.1: 2002/05/14-2010/10/21
Envisat V2.1 new orbit : 2010/10/26-2012/04/08