Optical instruments are normally calibrated with incandescent irradiance or radiance sources. Recently, accurate calibrations using solar radiation have been demonstrated in the visible and near-IR regions (VNIR). The solar-radiation based calibration (SRBC) has major advantage in that the calibration source is the same source used on-orbit by earth- viewing remote sensing sensors such as the ASTER, MODIS, and Landsat 7 ETM+ sensors. In this paper, such a radiometer calibration covering the region between 740 and 2400 nm is presented and compared with lamp-based laboratory calibrations. This work extends the spectral range over which a calibration using solar-radiation has been made.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.