The present French documentation (from Paul Poli) describes the pre-processing of zenith total delays (ZTD) observations from ground-based GPS stations. This pre-processing requires in input: GPS ZTD observations as well as a GPS station selection list. The pre-processing as presented here is applied in the 4DVAR ARPEGE, 3DVAR ALADIN, and 3DVAR AROME assimilation systems.

Cette note décrit le pré-traitement des données GPS sol avant leur assimilation dans ARPEGE, ALADIN, et AROME.