The emerging radiation field

The last chapter dealt with the interaction of radiation with matter, mostly in the gaseous, but also in the liquid and solid phases. Absorption coefficients of infrared active gases, emission and scattering properties of surfaces, and single scattering albedos and phase functions of aerosols were considered. Applications of these concepts, along with the principles of radiative transfer discussed in Chapter 2, enable us to calculate the emerging radiation field of a planet or satellite. 

---

Summarizing this chapter, we have derived both analytic and numerical procedures for calculating the emerging radiation field provided we can specify the vertical distributions of the temperature as well as the gas and particle compositions. It is also necessary to know the absorption and scattering properties of atmospheric volume elements on a microscopic scale. In the next chapter we discuss these properties before proceeding with the task of computing the intensity of the outgoing radiation field. 

In Section 6.1 we show the effects of finite spectral resolution and other instrument characteristics on the recording of the emerging radiation field. Infrared data from the terrestrial planets, that is Venus, Earth, and Mars, are treated in a comparative way in Section 6.2. Emphasis is given to an understanding of the physical principles that cause the structure in the measured spectra. The spectra of the giant planets are discussed in Section 6.3, again in a comparative manner. Section 6.4 is devoted to Titan as a satellite with a deep atmosphere it is in a class by itself The last section in this chapter (6.5) is concerned with astronomical bodies without substantial atmospheres. Mercury, the Moon, and lo are most interesting examples of this class of objects. The numerical treatment of information retrieval is postponed until Chapter 8. 

The theories of radiative transfer, molecular spectroscopy, and atmospheric physics are first combined to show how it is possible to calculate the infrared spectra of model planetary atmospheres. Next the authors describe the instrumental techniques, in order to assess the effect of real instruments on the measurement of the emerging radiation field. Finally, techniques that allow the retrieval of atmospheric and surface parameters from observations are examined. There are plenty of examples from ground-based and space observations that demonstrate the methods of finding temperatures, gas compositions, and certain parameters of the solid surface. All planets from Mercury to Pluto, many of their satellites, asteroids, and comets are discussed. 

An assembly of molecules, weakly interacting in a condensed phase, has the general features of an oriented gas system, showing spectral properties similar to those of the constitutive molecules, modulated by new collective and cooperative intrinsic phenomena due to the coherent dynamics of the molecular excitations. These phenomena emerge mainly from the resonant interactions of the molecular excitations, which have to obey the lattice symmetry (with edge boundary, dimensionality, internal radiation, and relativistic conditions), with couplings to the phonon field and to the free radiation field. 

Even in coherent processes whose nature serves to define the principal direction of the emergent radiation, and where the initial and final molecular states are necessarily identical, the general theory leads to quantum amplitudes in which the final state of the radiation field is not yet completely specified with regard to the wavevector and polarization of the emitted radiation. As such, the sums over all possible values of k and X should remain in the general amplitudes of the radiation tensor p. However, the restrictions imposed on parametric... 

The modern tendency of describing practically everything in this world by a combination of a few letters (acronyms) has also penetrated the field of Materials Characterization. The table below gives the meaning of the acronym for every technique listed, the form and size of the required sample (bulk, surface, fUm, liquid, powder, etc.), the nature of the incoming and of the emerging radiation, the depth and the lateral spatial resolution that can be probed, and the information obtained from the experiment. The last column lists one or two major references to the technique described. 

Emergency In vivo Tooth Dosimeter Oral Dosimeter. Tooth enamel is only material that records the accumulated radiation exposure dose in the past in a human body. An equipment for rapid dosimetry of teeth without their extraction was fabricated upon demand by Chernobyl medical doctors to judge whether immediate medical care such as spinal transplantation is necessary.97 A portable test apparatus of in vivo human tooth dosimeter consists of a resonator cavity with an aperture and a permanent magnet of Nd-B-Fe alloy (Neomax). The sensitivity is not sufficient due to the low Q factor and non-uniform magnetic field at the tooth. 

---