Results 181 to 190 of about 28,409 (225)

Aerosol optical thickness retrieval from Sun photometer measurements

Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium, 2002
Aerosol optical thickness (AOT) is usually retrieved from Sun photometer (SP) signal in three steps: (1) SP calibration (determination of "zero signal" I/sub 0/); (2) retrieval of the total optical thickness; (3) removal of the molecular scattering and absorption.
A. Ignatov, I. Dergileva, Yu. Ratner, S. Sakerin, D. Kabanov   +4 more
openaire   +1 more source

General method for calibrating Sun photometers

Applied Optics, 1994
A general method for calibrating Sun photometers that relaxes the constraints on atmospheric conditions is described. Instead of requiring constant extinction conditions the method requires only that the relative aerosol size distribution remains constant during observations over a range of air masses during a morning or afternoon.
openaire   +2 more sources

Maritime aerosol optical thickness measured by handheld sun photometers

Remote Sensing of Environment, 2004
For several years, the NASA SIMBIOS Project has collected, processed, and archived optical aerosol data from shipboard sun photometers. The calibration, processing, quality control, and archival methodology for handheld sun photometers are described here, along with their deployment statistics.
Kirk D. Knobelspiesse, Christophe Pietras, Giulietta S. Fargion, Menghua Wang, Robert Frouin, Mark A. Miller, Ajit Subramaniam, William M. Balch   +7 more
openaire   +1 more source

Sky type discrimination using a ground-based sun photometer

Atmospheric Research, 2001
A 2-year feasibility study was conducted at the USGS EROS Data Center, South Dakota (43.733°N, 96.6167°W) to assess whether a four-band, ground-based, sun photometer could be used to discriminate sky types. The results indicate that unique spectral signatures do exist between sunny skies (including clear and hazy skies) and cirrus, and cirrostratus ...
T.P DeFelice, B.K Wylie
openaire   +1 more source

Calibration of Sun photometers and sky radiance sensors

2001
The purpose of this technical report is to provide current documentation of the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project Office activities on in situ aerosol optical thickness (i.e., protocols, data QC and analysis).
Pietras, Christophe, Miller, Mark, Frouin, Robert, Eck, Thomas, Holben, Brent, Marketon, John   +5 more
openaire   +1 more source

Estimation of Cirrus Optical Thickness from Sun Photometer Measurements

Journal of Applied Meteorology, 1994
Abstract A method is proposed to estimate the optical thickness of cirrus clouds from ground-based sun photometry. Transfer calculations of solar radiation in ice clouds were made by the Monte Carlo method. A scattering phase function presented by Takano and Liou was employed for ice clouds.
Masataka Shiobara, Shoji Asano
openaire   +1 more source

The calibration of Microtops II sun photometers over ocean

SPIE Proceedings, 2010
Aerosol plays important on the climate and environment. Aerosol parameter, such as optical thickness, is usually measured by the 5-channel hand-held MICROTOPS II sun photometer and the calibration coefficients of instruments measurements play a vital role in determining the accuracy of the aerosol optical thickness. However, long time usage and some
Zengzhou Hao, Difeng Wang, Delu Pan, Linchong Kang   +3 more
openaire   +1 more source

A Photometer for Measurement of Sky Brightness Near the Sun

Journal of the Optical Society of America, 1948
Measurement of the brightness of the sky near the sun is difficult because instrumental scattered light originating in the solar disk is usually many times brighter than light from the sky. An optical system for eliminating this scattered light and providing means for a visual photometric comparison between the sky and the sun has been constructed and ...
openaire   +2 more sources

Total water vapor content retrieval from sun photometer data

Atmospheric and Oceanic Optics, 2013
Simulation of Sun photometer measurements for two regions of Russia is made and total water vapor content retrieval errors, caused by variations in meteorological parameters and the application of empirical formulas used in AERONET, are estimated.
K. M. Firsov, T. Yu. Chesnokova, E. V. Bobrov, I. I. Klitochenko   +3 more
openaire   +1 more source

Sun photometer with light-emitting diodes as spectrally selective detectors

Applied Optics, 1992
Light-emitting diodes can function as spectrally selective detectors in a miniature, inexpensive sun photometer that measures atmospheric turbidity and precipitable water.
openaire   +2 more sources