Results 21 to 30 of about 22,657 (210)

Two-Stage Nested Array Direction of Arrival Estimation for Mixed Signals

Sensors, 2022
In this paper, a novel two-stage subspace-based direction of arrival (DOA) estimation algorithm with the nested array is proposed for mixed signals containing circular and non-circular ones.
Wanru Li, Ke Deng
doaj   +1 more source

Cross-coupled DOA trackers [PDF]

IEEE Transactions on Signal Processing, 1997
A new robust, low complexity algorithm for multiuser tracking is proposed, modifying the two-stage parallel architecture of the estimate-maximize (EM) algorithm. The algorithm copes with spatially colored noise, large differences in source powers, multipath, and crossing trajectories.
Pérez Neira, Ana Isabel, Lagunas Hernandez, Miguel A., Kirlin, R L   +2 more
openaire   +3 more sources

Retrieval and evaluation of tropospheric-aerosol extinction profiles using multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements over Athens, Greece [PDF]

Atmospheric Measurement Techniques, 2021
In this study, we report on the retrieval of aerosol extinction profiles from ground-based scattered sunlight multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements, carried out at Athens, Greece.
M. Gratsea, M. Gratsea, T. Bösch, P. Kokkalis, P. Kokkalis, A. Richter, M. Vrekoussis, M. Vrekoussis, S. Kazadzis, S. Kazadzis, A. Tsekeri, A. Papayannis, M. Mylonaki, V. Amiridis, N. Mihalopoulos, N. Mihalopoulos, N. Mihalopoulos, E. Gerasopoulos   +17 more
doaj   +1 more source

Three years of greenhouse gas column-averaged dry air mole fractions retrieved from satellite – Part 2: Methane [PDF]

, 2008
Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases. SCIAMACHY on ENVISAT is the first satellite instrument whose measurements are sensitive to concentration changes of the two gases at all altitude levels ...
Bergamaschi, P., Bovensmann, H., Buchwitz, M., Burrows, J.P., Peters, W., Schneising, O.   +5 more
core   +6 more sources

Gas emission strength and evolution of the molar ratio of BrO/SO2 in the plume of Nyiragongo in comparison to Etna [PDF]

, 2015
Airborne and ground-based differential optical absorption spectroscopy observations have been carried out at the volcano Nyiragongo (Democratic Republic of Congo) to measure SO2 and bromine monoxide (BrO) in the plume in March 2004 and June 2007 ...
Aiuppa, Aiuppa, Aiuppa, Aiuppa, Aiuppa, Bobrowski, Bobrowski, Bobrowski, Bobrowski, Bobrowski, Boichu, Bureau, Carn, Chakrabarti, Delmelle, Dorf, Durieux, Ebinger, Fitzenberger, Galle, Galle, Gerlach, Gerlach, Gerlach, Giggenbach, Glasow, Glasow, Glasow, Glasow, Halmer, Honda, Horrocks, Hönninger, Kelly, Kern, Kitto, Komorowski, Kutterolf, Lary, Lazrus, Martin, Martin, Noguchi, Oppenheimer, Parrella, Pennisi, Pinto, Platt, Pundt, Pyle, Richter, Richter, Roberts, Robock, Rogers, Rogers, Saiz-Lopez, Salawitch, Sawyer, Schofield, Schofield, Sedlacek, Shinohara, Sturges, Surl, Symonds, Tazieff, Theys, Theys, Wennberg, Witt, Wittmer, Woods, Yang   +73 more
core   +1 more source

Study on the measurement of isoprene by differential optical absorption spectroscopy [PDF]

Atmospheric Measurement Techniques, 2021
In this paper, the continuous online measurements of isoprene in the atmosphere have been carried out by using differential optical absorption spectroscopy (DOAS) in the band of 202.71–227.72 nm for the first time.
S. Gao, S. Gao, S. Wang, S. Wang, C. Gu, J. Zhu, R. Zhang, Y. Guo, Y. Yan, B. Zhou, B. Zhou, B. Zhou, B. Zhou   +12 more
doaj   +1 more source

The influence of random element displacement on DOA estimates obtained with (Khatri-Rao-)root-MUSIC [PDF]

, 2014
Although a wide range of direction of arrival (DOA) estimation algorithms has been described for a diverse range of array configurations, no specific stochastic analysis framework has been established to assess the probability density function of the ...
Inghelbrecht, Veronique, Rogier, Hendrik, Van Hecke, Tanja, Verhaevert, Jo   +3 more
core   +2 more sources

A Low-Complexity ESPRIT-Based DOA Estimation Method for Co-Prime Linear Arrays

Sensors, 2016
The problem of direction-of-arrival (DOA) estimation is investigated for co-prime array, where the co-prime array consists of two uniform sparse linear subarrays with extended inter-element spacing.
Fenggang Sun, Bin Gao, Lizhen Chen, Peng Lan   +3 more
doaj   +1 more source

MAX-DOAS measurements of tropospheric NO₂ and HCHO in Nanjing and a comparison to ozone monitoring instrument observations [PDF]

Atmospheric Chemistry and Physics, 2019
In this paper, we present long-term observations of atmospheric nitrogen dioxide (NO2) and formaldehyde (HCHO) in Nanjing using a Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument.
K. L. Chan, Z. Wang, A. Ding, K.-P. Heue, Y. Shen, J. Wang, F. Zhang, Y. Shi, N. Hao, M. Wenig   +9 more
doaj   +1 more source

On the absolute calibration of SO₂ cameras [PDF]

Atmospheric Measurement Techniques, 2013
Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral ...
P. Lübcke, N. Bobrowski, S. Illing, C. Kern, J. M. Alvarez Nieves, L. Vogel, J. Zielcke, H. Delgado Granados, U. Platt   +8 more
doaj   +1 more source