Simplified computation of earth thermal and albedo radiation incident on a spacecraft

'!lie integral used for the computation of the earth thermal and albedo flux on a section of a satellite is directly integrable if the projected area is represented by a truncated Fourier series in the aspect angle. A great saving in computer time results from this representation. The series for a general surface of revolution, whose axis coincides with the axis of rotational synunet.7 of the satellite, ls obtained by dividing the surface into elemental conical frustums and averaging the series for a cone over the generating curve.