I am trying to do an atmospheric correction on a Quickbird scene. I am creating a user-defined geometry which requires six parameters. The six parameters are solar zenith angle, solar azimuth angle, view zenith angle, view azimuth angle, month, and day. The Quickbird metadata file gives a "mean elevation angle of the sun from horizontal" so I think I am correct in assuming that
mean solar zenith angle = 90 - meanSunEl
mean solar azimuth angle = meanSunAz
I am unclear about how to determine the view zenith angle and view azimuth angle. The Quickbird documentation gives meanSatEl as the "mean elevation angle of the satellite with respect to the center line, in degrees." I am unsure what is meant by "respect to the center line." Zenith? Would it simply be
mean view zenith angle = 90 - meanSatEl ?
I also am unsure whether view azimuth angle is equivalent to meanSatAz, which is defined as "mean azimuth angle of the satellite with respect to the center line, in degrees." The metadata also has values for InTrackViewAngle, CrossTrackViewAngle, and offNadirViewAngle.