Chapter 2
Special Features of Self-surface (Heat)
Radiation Forming
Abstract Radiation of the hypothetical black body is considered. General
notations and basic equations are presented for calculation spectral radiation of
black and real bodies.
2.1 The Black Body Radiation
It is known from experiments that all matters emit constantly electromagnetic
waves. The electromagnetic radiation embraces practically all ranges of wavelength. By its nature this radiation is called self heat radiation, because it arises
while molecules transmit at exciting level with kinetic interaction (collisions) with
consequently returning to unexciting level with quantum emitting. Thus it is
understandable that the intensity of the self heat radiation is to be linked with
inner energy of matter that is directly proportional to the temperature and is to
depend on physical structure of matter.
Dependencies of forming the self heat radiation field allow obtaining an analytical link between quantities of energy emitted by an object at different wavelength in
different directions and object’s parameters. But these dependencies are simple
only for ideal absorber and emitter of electromagnetic waves, which is blackbody
(BB) or perfect radiator.
The blackbody is an hypothetical body that emits the maximal radiation for the
temperature, does not reflect or transport the incident energy and absorbs all
incident energy falling at all wavelengths and from all directions. The notation of
blackbody is the key one for description of heat radiation transfer. The perfect
radiator blackbody is used as an etalon for calibration of spectral instruments within
spectral IR-ranges.
Max Planck (1858–1947) has assumed two presumptions concerning properties
of atom oscillators in 1901 aiming theoretically explain spectral distribution of
radiation emitted by heated cavity. Firstly Planck had postulated that the energy of
the harmonic oscillator is expressed as E ¼ nhf, where f is the oscillator frequency;
I. Melnikova et al., Remote Sensing of the Environment and Radiation Transfer,
DOI 10.1007/978-3-642-14899-6_2, # Springer-Verlag Berlin Heidelberg 2012
19
Special Features of Self-surface (Heat)
Radiation Forming
Abstract Radiation of the hypothetical black body is considered. General
notations and basic equations are presented for calculation spectral radiation of
black and real bodies.
2.1 The Black Body Radiation
It is known from experiments that all matters emit constantly electromagnetic
waves. The electromagnetic radiation embraces practically all ranges of wavelength. By its nature this radiation is called self heat radiation, because it arises
while molecules transmit at exciting level with kinetic interaction (collisions) with
consequently returning to unexciting level with quantum emitting. Thus it is
understandable that the intensity of the self heat radiation is to be linked with
inner energy of matter that is directly proportional to the temperature and is to
depend on physical structure of matter.
Dependencies of forming the self heat radiation field allow obtaining an analytical link between quantities of energy emitted by an object at different wavelength in
different directions and object’s parameters. But these dependencies are simple
only for ideal absorber and emitter of electromagnetic waves, which is blackbody
(BB) or perfect radiator.
The blackbody is an hypothetical body that emits the maximal radiation for the
temperature, does not reflect or transport the incident energy and absorbs all
incident energy falling at all wavelengths and from all directions. The notation of
blackbody is the key one for description of heat radiation transfer. The perfect
radiator blackbody is used as an etalon for calibration of spectral instruments within
spectral IR-ranges.
Max Planck (1858–1947) has assumed two presumptions concerning properties
of atom oscillators in 1901 aiming theoretically explain spectral distribution of
radiation emitted by heated cavity. Firstly Planck had postulated that the energy of
the harmonic oscillator is expressed as E ¼ nhf, where f is the oscillator frequency;
I. Melnikova et al., Remote Sensing of the Environment and Radiation Transfer,
DOI 10.1007/978-3-642-14899-6_2, # Springer-Verlag Berlin Heidelberg 2012
19