Wave model: Radiometry and coherence for quasi-homogeneous, scalar wavefields
Abstract
On the basis of Wolf's wave equations for the propagation of coherence a new, explicit representation of the cross-spectral density function is obtained in terms of a generalized radiance function which is constant along geometrical rays. By means of a series development of this representation it is shown that the laws of classical radiometry and free space radiative transfer are valid provided the radiance function (the specific intensity) may be considered constant over distances comparable to the transverse coherence length. The corresponding expression for the cross-spectral density function is identical to a result previously obtained that, implies for quasi-homogenous wavefields, the radiance function is everywhere uniquely related to the field coherence by a gereralized van Cittert-Zernike theorem.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- October 1981
- Bibcode:
- 1981STIN...8320067P
- Keywords:
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- Radiance;
- Radiometric Resolution;
- Spectral Energy Distribution;
- Water Waves;
- Wave Propagation;
- Geometrical Optics;
- Homogeneity;
- Wave Equations;
- Fluid Mechanics and Heat Transfer