Results 71 to 80 of about 2,581 (194)

First MAX‐DOAS Observations of Formaldehyde and Glyoxal in Phimai, Thailand [PDF]

Journal of Geophysical Research: Atmospheres, 2018
AbstractMultiaxis differential optical absorption spectroscopy (MAX‐DOAS) observations were performed for the first time in Thailand at the rural site of Phimai (15.18°N, 102.56°E). Vertical profiles of eight components were retrieved separately using the Japanese MAX‐DOAS profile retrieval algorithm, version 2.
H. M. S. Hoque, H. Irie, A. Damiani
openaire   +1 more source

Retrieval of tropospheric NO₂ using the MAX-DOAS method combined with relative intensity measurements for aerosol correction [PDF]

Atmospheric Measurement Techniques, 2010
Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) is a technique to measure trace gas amounts in the lower troposphere from ground-based scattered sunlight observations.
P. F. Levelt, P. Wang, P. Stammes, A. J. M. Piters, T. Vlemmix   +4 more
doaj   +1 more source

Low‐Complexity DOA Estimation: Combining VSSLMS With FFT Spectrum Estimation

Electronics Letters, Volume 62, Issue 1, January/December 2026.
This letter presents a novel, low‐complexity framework for DOA estimation. The proposed method achieves a significant reduction in computational complexity—from O(ML) to O(M log L)—compared to conventional SSE methods. Crucially, as illustrated in the accompanying figure, the method maintains high estimation accuracy, outperforming standard SSE‐based ...
Lei Sun, Ding Ding, Songbai Zhang, Xiao Dai, Chaoyang Xu   +4 more
wiley   +1 more source

A simple and versatile cloud-screening method for MAX-DOAS retrievals [PDF]

Atmospheric Measurement Techniques, 2014
Abstract. We present a cloud-screening method based on differential optical absorption spectroscopy (DOAS) measurements, more specifically using zenith sky spectra and O4 differential slant-column densities (DSCDs). Using the colour index (CI), i.e. the ratio of the radiance at two wavelengths, we define different sky conditions including clear, thin ...
C. Gielen, M. Van Roozendael, F. Hendrick, G. Pinardi, T. Vlemmix, V. De Bock, H. De Backer, C. Fayt, C. Hermans, D. Gillotay, P. Wang   +10 more
openaire   +4 more sources

Validation of OMI HCHO Products Using MAX-DOAS observations from 2010 to 2016 in Xianghe, Beijing: Investigation of the Effects of Aerosols on Satellite Products

Remote Sensing, 2019
Formaldehyde (HCHO) is one of the most abundant hydrocarbons in the atmosphere. Its absorption features in the 320⁻360 nm range allow its concentration in the atmosphere to be retrieved from space.
Yapeng Wang, Zifeng Wang, Chao Yu, Songyan Zhu, Liangxiao Cheng, Ying Zhang, Liangfu Chen   +6 more
doaj   +1 more source

MAX-DOAS NO₂ observations over Guangzhou, China; ground-based and satellite comparisons [PDF]

Atmospheric Measurement Techniques, 2018
In this study, the tropospheric NO2 vertical column density (VCD) over an urban site in Guangzhou megacity in China is investigated by means of MAX-DOAS measurements during a campaign from late March 2015 to mid-March 2016.
T. Drosoglou, M. E. Koukouli, N. Kouremeti, A. F. Bais, I. Zyrichidou, D. Balis, R. J. van der A, R. J. van der A, J. Xu, A. Li   +9 more
doaj   +1 more source

Loop Matching Pursuit Multistation TDOA Estimation Method Based on Noncircular Signal

IET Radar, Sonar &Navigation, Volume 20, Issue 1, January/December 2026.
The existing TDOA estimation methods based on orthogonal matching pursuit only consider the scenario of circular signal and are prone to the degradation of estimation performance due to atom misselection under small samples and low signal‐to‐noise ratio.
Zeyu Wang, Ding Wang, Jiexin Yin, Nae Zheng   +3 more
wiley   +1 more source

Introduction to special issue: the TransBrom Sonne expedition in the tropical West Pacific [PDF]

, 2013
This special section of Atmospheric Chemistry and Physics gives an overview of scientific results, collected during a West Pacific ship expedition in October 2009 with the Research Vessel (R/V) Sonne.
Krüger, Kirstin, Quack, Birgit
core   +1 more source

Watching Radical Geography: Spaces and Practices of Authoritarian Surveillance in ‘Democratic’ and ‘Dictatorial’ Brazil

Antipode, Volume 58, Issue 1, January 2026.
ABSTRACT This paper addresses stories of surveillance of Brazilian critical/radical geographers, drawing on innovative sources. That is, the folders and reports through which the political police and related institutions watched critical and radical scholars during the 20th century in all Brazilian states and abroad, under both ‘dictatorial’ and ...
Federico Ferretti, Guilherme Ribeiro
wiley   +1 more source

MAX-DOAS observations of ship emissions in the North Sea

Marine Pollution Bulletin
Shipping emissions were measured in Dunkirk, France. Elevated aerosol extinction coefficients (AEC), nitrogen dioxide (NO2) and sulphur dioxide (SO2) were observed up to 500 m from surface. Formaldehyde (HCHO) did not show an increase every time, which suggests that oxidation of emitted volatile organic compounds (VOCs) took longer than the transport ...
Mahajan, Anoop, Tinel, Liselotte, Riffault, Véronique, Guilbaud, Sarah, D’anna, Barbara, Cuevas, Carlos, Saiz-Lopez, Alfonso   +6 more
openaire   +4 more sources