Water vapor spectroscopy data for the 720 nm absorption band (
4ν polyad) are validated in the context of atmospheric radiative transfer calculations. We validate line parameters from the HITRAN-2000 database and from the ULB-UFR-BIRA database which have been used for the 2004 release of HITRAN. For this purpose, ground-based high resolution observations of the direct solar radiation are compared with simulated spectra. Line parameters are selected for validation based on a full error characterization including instrument noise and uncertainties in the atmospheric profile data. For a subset of the line parameters validated in the present study independent high-accuracy data are available. The comparison with these independent reference data confirms the capability of our approach to improve water vapor spectroscopic data.