Determination of beam transmittance and path radiance in the four optical bands of the ERTS-satellite

The problem of correcting data from the optical bands of the Earth Resources Technology Satellite (ERTS) for path radiance and transmittance is discussed. Techniques are described whereby these parameters may be determined from simple ground measurements with a filter radiometer and used to make the necessary corrections before digital data interpretation. The procedure allows satellite data to be expressed in the same scale as ground reflectance measurements. The signatures of ground objects are independent of atmospheric conditions and the position of the sun. The accuracy of the reflectance values calculated from satellite data on the basis of ground measurements of atmospheric mask parameters is comparable with the accuracy of ground reflectance measurements.