A tropospheric propagation path obstructed by transverse obstacles is considered. The obstacles are modeled as perfectly absorbing half planes. Propagation loss relative to the unobstructed path is calculated by means of the method of Epstein and Peterson and the method of Deygout. These results are compared with those predicted by spectral diffraction theory. The comparison is made entirely outside the transition regions surrounding the shadow boundaries, permitting simplification of the spectral theory to the familiar geometrical theory of diffraction. The comparisons are used to explain the apparent superiority of the Deygout method over that of Epstein and Peterson in predicting the link loss.