| Infrared Airglow and Contamination Modeling |
OCT 1999 |
124 pages |
| Authors:
S. M. Adler-Golden; A. Berk; P. K. Acharya; L. S. Bernstein; SPECTRAL SCIENCES INC BURLINGTON MA
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 | This report describes work performed to evaluate our understanding of infrared (IR) atmospheric phenomenology through comprehensive analysis of spectral and in-band radiance field data. Computer models of atmospheric IR radiation used for these analyses include the standard AFRL codes MODTRAN, SHARC, and SAMM. MODTRAN is a rapid, local thermodynamic equilibrium (LTE) code for low- to moderate-resolution spectra. SHARC calculates emission and transmission spectra in the 2 - 40 micrometers region ... |
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| Recent Upgrades to MODTRAN - New Solar Irradiance and Instrument Scanning Functions |
28 SEP 1998 |
19 pages |
| Authors:
P. K. Acharya; A. Berk; L. S. Bernstein; D. C. Robertson; J. H. Chetwynd; SPECTRAL SCIENCES INC BURLINGTON MA
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| Recent upgrades are intended to make MODTRAN a more accurate, convenient and versatile atmospheric modeling tool. The current default solar irradiance database due to Kurucz was corrected in the 310-340 nm region using measured data. Several other data sets are also made available to the user. The user can also use his/her won data residing in a file. Examination confirms that the corrected Kurucz data is ... |
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| Development of Atmospheric Infrared Emission Models |
19 DEC 1997 |
79 pages |
| Authors:
J. W. Duff; J. H. Gruninger; R. L. Sundberg; P. K. Acharya; S. M. Adler-Golden; A. Berk; L. S. Bernstein; D. C. Robertson; SPECTRAL SCIENCES INC BURLINGTON MA
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| This report describes the development of atmospheric infrared (IR) radiance models to describe atmospheric NLTE radiation and structure in the IR spectral region for arbitrary diurnal conditions, Several of the models have been included into the suite of standard Air Force atmospheric radiation computer models. These models calculate the radiation from quiescent, auroral, and structured atmospheres in the 2-40 microns spectral region for arbitrary paths above 30 km under nighttime, ... |
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| User's Manual For SHARC-4 The Strategic High-Altitude Radiance Code |
31 MAR 97 |
143 pages |
| Authors:
J. H. Gruninger; R. L. Sundberg; P. K. Acharya; J. W. Duff; J. H. Brown; PHILLIPS LAB HANSCOM AFB MA
|
| The Strategic High-Altitude Radiance Code, SHARC-4, calculates atmospheric radiance and transmission over a 1 - 40 micrometers spectral region for arbitrary lines of sight (LOS) between 30 and 300 km altitude. It models radiation due to non-local thermodynamic equilibrium (NLTE) molecular emissions, the dominant sources at these altitudes. This fourth release of SHARC has been upgraded to model atmospheric structure due to stochastic processes described by a temperature and density ... |
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| User's Manual for SAMM, SHARC And MODTRAN Merged |
30 APR 96 |
135 pages |
| Authors:
R. D. Sharma; J. H. Brown; A. Berk; P. K. Acharya; J. Gruninger; SPECTRAL SCIENCES INC BURLINGTON MA
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| The SAMM, SHARC And MODTRAN Merged model calculates atmospheric radiance and transmission over the 1 - 40 micrometers spectral region for arbitrary lines of sight (LOS) from the ground through the thermosphere, 300 km altitude. It models radiation due to non-local thermodynamic equilibrium (non- LTE) molecular emissions. the dominant source at the higher altitudes. In the lower atmosphere, LOS bending due to refraction is modeled. Molecular and aerosol scattering is ... |
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| Upgraded Line-of-Sight Geometry Package and Band Model Parameters for MODTRAN |
MAY 93 |
22 pages |
| Authors:
P. K. Acharya; D. C. Robertson; A. Berk; SPECTRAL SCIENCES INC BURLINGTON MA
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| The MODTRAN atmospheric transmittance and radiance code was upgraded with new band model parameters calculated using the HITRAN-92 line atlas. The (1/d) band model parameters for O sub 3 were adjusted to give better agreement with the corresponding line-by-line FASCOD3 calculations for long paths in the 20-50 km altitude region. More accurate line-of-sight (LOS) geometry routines were incorporated for greater consistency between the geometry parameters. Furthermore, MODTRAN can now handle ... |
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| Investigations into Atmospheric Radiative Processes in the 50 - 300 km Regime |
30 APR 91 |
112 pages |
| Authors:
D. C. Robertson; P. K. Acharya; S. M. Adler-Golden; L. S. Bernstein; F. Bien; SPECTRAL SCIENCES INC BURLINGTON MA
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| This study describes research into high-altitude infrared (IR) radiance models to describe sources of high-altitude NLTE radiation in the IR spectral region. Many of the models have been combined into SHARC, the Strategic High Altitude Radiance Code. SHARC calculates the radiation from quiescent and auroral atmospheres in the 2-40 micrometer spectral region for arbitrary paths that lie above 50 km, including space viewing. In related activities, analyses of data taken ... |
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| Surface Response to Cloud Shadowing |
20 FEB 91 |
33 pages |
| Authors:
A. Berk; D. C. Robertson; P. K. Acharya; SPECTRAL SCIENCES INC BURLINGTON MA
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| This study investigated the response of surface temperature to cloud shadows. A quantitative model applicable to IR backgrounds was developed. Time- dependent heat flow and energy budget equations have been solved to determine the diurnal variation in surface ground temperatures for a dry, sandy soil with a simple vegetation layer under various cloud conditions. Ground temperatures were determined to vary up to 2K in the first minute following cloud shadowing ... |
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| The Strategic High-Altitude Atmospheric Radiation Code (SHARC) User Instructions |
03 FEB 89 |
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| Authors:
R. L. Sundberg; J. W. Duff; L. S. Bernstein; P. K. Acharya; J. H. Gruninger; SPECTRAL SCIENCES INC BURLINGTON MA
|
 | This report describes how to implement and use the Strategic High- Altitude Radiance Code (SHARC). SHARC calculates atmospheric radiation for paths from 60 to 300 km altitude in the 2-40 micron spectral region. It models radiation due to NLTE (Non-Local Thermodynamic Equilibrium) molecular emissions which are the dominant sources at these altitudes. This initial version of SHARC includes the five strongest IR radiators, CO2, NO, O3, H20, and CO. The ... |
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