In the Optics InfoBase, by the American Institute of Physics’ Optical Society of America:
Authors: Abraham Kribus, Irna Vishnevetsky, Eyal Rotenberg, and Dan Yakir
Applied Optics, Vol. 42, Issue 10, pp. 1839-1846
(120.0280) Instrumentation, measurement, and metrology : Remote sensing and sensors
(260.3060) Physical optics : Infrared
(300.2140) Spectroscopy : Emission
Accurate knowledge of surface emissivity is essential for applications in remote sensing (remote temperature measurement), radiative transport, and modeling of environmental energy balances… » View Full Text: PDF
Hemispherical Spectral Emittance of Ablation Chars, Carbon, and Zirconia to 3700 deg K
Authors: R. G. Wilson; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
Abstract: The initial results of the application of special optical techniques to high-temperature emittance and reflectance studies of an ablation-material char and certain other refractory materials representative of those present in ablation residues formed during aerospace reentry operations are presented. Spectral hemispherical emittance and reflectance were determined with an image pyrometer integrated with an arc-imaging furnace for carbon, graphite, zirconia, and a phenolic-nylon ablation-material char at wavelengths from 0.37 micrometer to 0.72 micrometer for temperatures from 2100 deg K to 3700 deg K. The data obtained are compared with those of other investigations to the extent that the existence of comparable data permits. Surface-roughness properties of the materials studied were determined from measurements made with a light-section microscope. The dependence of the spectral hemispherical emittance of oxidized carbon at a wavelength of 0.65 micrometer on its surface-roughness properties was investigated experimentally and the emittance was found to be a linear function of the root-mean-square slope of the surface when the roughness is large compared with wavelength. p3
Limitations: APPROVED FOR PUBLIC RELEASE
Description: Technical note
Report Date: MAR 65
Report Number: A107703
From Paul van Delst’s Work Page at The Cooperative Institute for Meteorological Satellite Studies of the University of Wisconsin – Madison Space Science and Engineering Center.
The InfraRed Sea Surface Emissivity (IRSSE) model was developed for use in the Global Data Assimilation System (GDAS) at NCEP/EMC. Previously, the GDAS used an IRSSE model based on Masuda et al (1988). The Masuda model doesn’t account for the effect of enhanced emission due to reflection from the sea surface (only an issue for larger view angles) and the implementation was based on coarse spectral resolution emissivity data making its application to high resolution instruments, such as AIRS, problematic.
The old IRSSE model has been upgraded to use sea surface emissivities derived via the Wu and Smith (1997) methodology as described in van Delst and Wu (2000). The emissivity spectra are computed assuming the infrared sensors are not polarised and using the data of Hale and Querry (1973) for the refractive index of water, Segelstein (1981) for the extinction coefficient, and Friedman (1969) for the salinitiy/chlorinity corrections.
By: Hunter, A.; Adams, B.; Ramanujam, R.
Advanced Thermal Processing of Semiconductors, 2003. RTP 2003. 11th IEEE International Conference on RTP
Volume , Issue , 23-26 Sept. 2003 Page(s): 85 – 88
Digital Object Identifier 10.1109/RTP.2003.1249127
The design of an integrating reflectometer specific to the optical and spectral requirements of rapid thermal processing (RTP) is discussed. We report reflectance measurements of various materials. These measurements are correlated to in-situ emittance measurements recorded during rapid thermal processing. We also present the design of an optimized emissometer for an RTP chamber. We propose a means for correlating room temperature reflectance measurements to emittance standards for RTP.
This online page at The Pyrometer Instrument Company website, discusses the emissivity correction techniques employed in their products, the very narrow waveband devices called the Pyrolaser® (Shown here), the Pyrofiber® & the Optitherm® III Emissivity Technology.
(Notes: 1. The article speaks about “emissivity” but the spectral emissivity is implied due to the fact that these devices operate in very narrow wavebands at 865nm, 905nm or 1550nm, according to the model.
2. The article also provides a calculation and describes the radiant power of the laser as “energy”.)
Here’s an edited quote from the page:
“The emissivity is measured by firing a pulsed laser of monitored output energy to the target and measuring the reflected laser energy. Assuming that no energy is transmitted through the target (opaque material) the impinging energy must either be absorbed or reflected.
“The unknown absorbed energy can be calculated from the two measured quantities outgoing energy and reflected energy.
“Since absorptivity and emissivity are equal…the target emissivity (e) is known as soon as the absorptivity is known.
The temperature is measured by collecting the radiance in a narrow band (10-50nm) at the same wavelength (865nm, 905nm or 1550nm depending on the specific instrument) where emissivity is measured with the laser.”