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Lawrence S. Bernstein

Bio: Lawrence S. Bernstein is an academic researcher from Spectral Sciences Incorporated. The author has contributed to research in topics: Radiance & Atmospheric correction. The author has an hindex of 29, co-authored 106 publications receiving 5106 citations.


Papers
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Journal Article
TL;DR: In this article, the authors describe work done to increase the spectral resolution from 20 to 2 1/cm (FWHM) using the MODTRAN computer code, which is a moderate resolution version of the low-power low-voltage spectrum analyzer (LOWTRAN).
Abstract: : The LOWTRAN computer codes, with LOWTRAN 7 being the most current version, are widely used to calculate atmospheric transmittance and/or radiance in the infrared, visible and near ultraviolet spectral regions; LOWTRAN 7 has been extended to include the microwave spectral region The code is easily used, runs quickly and provides the user with a wide variety of atmospheric models and options Its spectral resolution is 20 1/cm Full Width/Half Maximum (FWHM) with calculations being done in 5 1/cm increments This report describes work done to increase LOWTRAN's spectral resolution from 20 to 2 1/cm (FWHM) Specifically, the technical objectives for this program were: 1) to develop algorithms providing 2 1/cm resolution (FWHM); 2) to model molecular absorption of atmospheric molecules as a function of temperature and pressure; 3) to calculate band model parameters for twelve LOWTRAN molecular species; and 4) to integrate the LOWTRAN 7 capabilities into the new algorithms, maintaining compatibility with the multiple scattering option MODTRAN, the final product of this effort, is a moderate resolution LOWTRAN code Molecular absorption is calculated in 1 1/cm spectral bins, while the other parts of the calculation remain unchanged The molecular species affected are: water vapor, carbon dioxide, ozone, nitrous oxide, carbon monoxide, methane, oxygen, nitric oxide, sulfur dioxide, nitrogen dioxide, ammonia and nitric acid

846 citations

Journal ArticleDOI
TL;DR: In this paper, the impact of these upgrades on predictions for AVIRIS viewing scenarios is discussed for both clear and clouded skies; the CK approach provides refined predictions for nadir and near-nadir viewing.

711 citations

Proceedings ArticleDOI
20 Oct 1999
TL;DR: The MODTRAN ground surface has been upgraded to include the effects of Bidirectional Reflectance Distribution Functions (BRDFs) and Adjacency as discussed by the authors, and the BRDFs are coupled into line-of-sight surface radiance calculations.
Abstract: MODTRAN4, the latest publicly released version of MODTRAN, provides many new and important options for modeling atmospheric radiation transport. A correlated-k algorithm improves multiple scattering, eliminates Curtis-Godson averaging, and introduces Beer's Law dependencies into the band model. An optimized 15 cm-1 band model provides over a 10-fold increase in speed over the standard MODTRAN 1 cm-1 band model with comparable accuracy when higher spectral resolution results are unnecessary. The MODTRAN ground surface has been upgraded to include the effects of Bidirectional Reflectance Distribution Functions (BRDFs) and Adjacency. The BRDFs are entered using standard parameterizations and are coupled into line-of-sight surface radiance calculations.

427 citations

Proceedings ArticleDOI
27 Oct 1999
TL;DR: In this paper, a new, state-of-the-art atmospheric correction algorithm for the solar spectral range has been developed based on the MODTRAN4 code, and the primary data products are surface reflectance spectra, column water vapor maps and relative surface elevation maps.
Abstract: A new, state-of-the-art atmospheric correction algorithm for the solar spectral range has been developed based on the MODTRAN4 code. The primary data products are surface reflectance spectra, column water vapor maps and relative surface elevation maps. In addition, a radiance simulation tool, an automated visibility retrieval algorithm and a spectral 'polishing' algorithm are included. Validations of retrievals have been carried out by analyzing data that encompass a variety of atmospheric and surface conditions. Some results and their implications for atmospheric correction and spectroscopy are discussed.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

328 citations

Proceedings ArticleDOI
TL;DR: The MODTRAN5(1a, in press) radiation transport (RT) model is a major advancement over earlier versions of the MODTRan(tm) atmospheric transmittance and radiance model.
Abstract: The MODTRAN5(1a, in press) radiation transport (RT) model is a major advancement over earlier versions of the MODTRAN(tm) atmospheric transmittance and radiance model. New model features include (1) finer spectral resolution via the Spectrally Enhanced Resolution MODTRAN(tm) (SERTRAN) molecular band model, (2) a fully coupled treatment of auxiliary molecular species, and (3) a rapid, high fidelity multiple scattering (MS) option. The finer spectral resolution improves model accuracy especially in the mid- and long-wave infrared atmospheric windows; the auxiliary species option permits the addition of any or all of the suite of HITRAN molecular line species, along with default and user-defined profile specification; and the MS option makes feasible the calculation of Vis-NIR databases that include high-fidelity scattered radiances.

258 citations


Cited by
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Journal ArticleDOI
TL;DR: The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity, and molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth.
Abstract: This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.

7,638 citations

Journal ArticleDOI
TL;DR: The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, exploring the transient optical sky, and mapping the Milky Way.
Abstract: (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pachon in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.

2,738 citations

Journal ArticleDOI
TL;DR: In this paper, the performance of the random forest classifier for land cover classification of a complex area is explored based on several criteria: mapping accuracy, sensitivity to data set size and noise.
Abstract: Land cover monitoring using remotely sensed data requires robust classification methods which allow for the accurate mapping of complex land cover and land use categories. Random forest (RF) is a powerful machine learning classifier that is relatively unknown in land remote sensing and has not been evaluated thoroughly by the remote sensing community compared to more conventional pattern recognition techniques. Key advantages of RF include: their non-parametric nature; high classification accuracy; and capability to determine variable importance. However, the split rules for classification are unknown, therefore RF can be considered to be black box type classifier. RF provides an algorithm for estimating missing values; and flexibility to perform several types of data analysis, including regression, classification, survival analysis, and unsupervised learning. In this paper, the performance of the RF classifier for land cover classification of a complex area is explored. Evaluation was based on several criteria: mapping accuracy, sensitivity to data set size and noise. Landsat-5 Thematic Mapper data captured in European spring and summer were used with auxiliary variables derived from a digital terrain model to classify 14 different land categories in the south of Spain. Results show that the RF algorithm yields accurate land cover classifications, with 92% overall accuracy and a Kappa index of 0.92. RF is robust to training data reduction and noise because significant differences in kappa values were only observed for data reduction and noise addition values greater than 50 and 20%, respectively. Additionally, variables that RF identified as most important for classifying land cover coincided with expectations. A McNemar test indicates an overall better performance of the random forest model over a single decision tree at the 0.00001 significance level.

1,901 citations

Journal ArticleDOI
Aaswath Raman1, Marc Abou Anoma1, Linxiao Zhu1, Eden Rephaeli1, Shanhui Fan1 
27 Nov 2014-Nature
TL;DR: An integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window demonstrates that the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day.
Abstract: A multilayer photonic structure is described that strongly reflects incident sunlight while emitting heat selectively through an atmospheric transparency window to outer space; this leads to passive cooling under direct sunlight of 5 degrees Celsius below ambient air temperature, which has potential applications in air-conditioning and energy efficiency.

1,788 citations

Journal ArticleDOI
TL;DR: The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was the first imaging sensor to measure the solar reflected spectrum from 400 nm to 2500 nm at 10 nm intervals as mentioned in this paper.

1,729 citations