A comprehensive underwater laser imaging model based on temporal and spatial broadening

2009 ◽  
Author(s):  
You-wei Huang ◽  
Wei-qi Jin ◽  
Kun Ding ◽  
Hai-lan Li ◽  
Feng-mei Cao ◽  
...  
Keyword(s):  
Laser Imaging ◽  
Model Based ◽  
Imaging Model ◽  
Temporal And Spatial ◽  
Underwater Laser

A model-based approach to measuring denitrification and greenhouse gas production in lakes

2021 ◽  
Author(s):  
Juliet Falco Ajambo-Doherty
Keyword(s):  
Greenhouse Gas ◽  
Atmospheric Pressure ◽  
Schmidt Number ◽  
Spatial Scales ◽  
Gas Production ◽  
System Model ◽  
Biogeochemical Processes ◽  
Model Based ◽  
Temporal And Spatial ◽  
System Metabolism

An existing whole-system model based on changes in dissolved N₂ concentration was modified for lentic systems. Field validations carried out at Christie Lake in Dundas, ON and Turtle Pond in Stoney Creek, ON (Canada). New model inputs included air temperature, atmospheric pressure, relative humidity, wind velocity, and Schmidt number. Mont Carlo analysis was integrated into the model to better constrain error in model estimates of denitrification, whole-system metabolism, and greenhouse gas production. Denitrification rates ranged from -419-4415 µmol N.m-².h-¹ in Christie Lake and from 10-74 µmol N.m-².h-¹ in Turtle Pond. N₂O production ranged from 915-10,635 nmol N.m-².h-¹ in Christie Lake and from -344-131 nmol N.m-².h-¹ in Turtle Pond. The whole-system model allows for the examination of biogeochemical processes at ecologically significant temporal and spatial scales.

scholarly journals Analysis of temporal and spatial variability of atmospheric CO<sub>2</sub> concentration within Paris from the GreenLITE™ laser imaging experiment

2019 ◽  
Vol 19 (22) ◽  
pp. 13809-13825 ◽  
Author(s):  
Jinghui Lian ◽  
François-Marie Bréon ◽  
Grégoire Broquet ◽  
T. Scott Zaccheo ◽  
Jeremy Dobler ◽  
...  
Keyword(s):  
Urban Canopy ◽  
Temporal Variations ◽  
Horizontal Resolution ◽  
Atmospheric Co2 ◽  
Laser Imaging ◽  
Near Surface ◽  
Co2 Concentrations ◽  
Temporal And Spatial ◽  
The City

Abstract. In 2015, the Greenhouse gas Laser Imaging Tomography Experiment (GreenLITE™) measurement system was deployed for a long-duration experiment in the center of Paris, France. The system measures near-surface atmospheric CO2 concentrations integrated along 30 horizontal chords ranging in length from 2.3 to 5.2 km and covering an area of 25 km2 over the complex urban environment. In this study, we use this observing system together with six conventional in situ point measurements and the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and two urban canopy schemes (Urban Canopy Model – UCM; Building Effect Parameterization – BEP) at a horizontal resolution of 1 km to analyze the temporal and spatial variations in CO2 concentrations within the city of Paris and its vicinity for the 1-year period spanning December 2015 to November 2016. Such an analysis aims at supporting the development of CO2 atmospheric inversion systems at the city scale. Results show that both urban canopy schemes in the WRF-Chem model are capable of reproducing the seasonal cycle and most of the synoptic variations in the atmospheric CO2 point measurements over the suburban areas as well as the general corresponding spatial differences in CO2 concentration that span the urban area. However, within the city, there are larger discrepancies between the observations and the model results with very distinct features during winter and summer. During winter, the GreenLITE™ measurements clearly demonstrate that one urban canopy scheme (BEP) provides a much better description of temporal variations and horizontal differences in CO2 concentrations than the other (UCM) does. During summer, much larger CO2 horizontal differences are indicated by the GreenLITE™ system than both the in situ measurements and the model results, with systematic east–west variations.

scholarly journals Analysis of temporal and spatial variability of atmospheric CO<sub>2</sub> concentration within Paris from the GreenLITE<sup>TM</sup> laser imaging experiment

2019 ◽  
Author(s):  
Jinghui Lian ◽  
François-Marie Bréon ◽  
Grégoire Broquet ◽  
T. Scott Zaccheo ◽  
Jeremy Dobler ◽  
...  
Keyword(s):  
Urban Canopy ◽  
Temporal Variations ◽  
Horizontal Resolution ◽  
Atmospheric Co2 ◽  
Laser Imaging ◽  
Near Surface ◽  
Co2 Concentrations ◽  
Temporal And Spatial ◽  
The City

Abstract. In 2015, the Greenhouse gas Laser Imaging Tomography Experiment (GreenLITETM) measurement system was deployed for a long-duration experiment in the center of Paris, France. The system measures near-surface atmospheric CO2 concentrations integrated along 30 horizontal chords ranging in length from 2.3 km to 5.2 km and covering an area of 25 km2 over the complex urban environment. In this study, we use this observing system together with six conventional in-situ point measurements and the WRF-Chem model coupled with two urban canopy schemes (UCM, BEP) at a horizontal resolution of 1 km to analyze the temporal and spatial variations of CO2 concentrations within the Paris city and its vicinity for the 1-year period spanning December 2015 to November 2016. Such an analysis aims at supporting the development of CO2 atmospheric inversion systems at the city scale. Results show that both urban canopy schemes in the WRF-Chem model are capable of reproducing the seasonal cycle and most of the synoptic variations in the atmospheric CO2 point measurements over the suburban areas, as well as the general corresponding spatial differences in CO2 concentration that span the urban area. However, within the city, there are larger discrepancies between the observations and the model results with very distinct features during winter and summer. During winter, the GreenLITETM measurements clearly demonstrate that one urban canopy scheme (BEP) provides a much better description of temporal variations and horizontal differences in CO2 concentrations than the other (UCM) does. During summer, much larger CO2 horizontal differences are indicated by the GreenLITETM system than both the in-situ measurements and the model results, with systematic east-west variations.

Underwater Optical Imaging Technology and its Applications

2013 ◽  
Vol 710 ◽  
pp. 408-412
Author(s):  
Rong Zeng ◽  
Jun Hua He ◽  
Pei Lv
Keyword(s):  
Compressive Sensing ◽  
Optical Imaging ◽  
Laser Scanning ◽  
Laser Imaging ◽  
Imaging Technology ◽  
Underwater Laser ◽  
Scanning Imaging

The applications of underwater optical imaging technology are reviewed. The main types of underwater laser imaging technology are introduced, such as underwater laser scanning imaging and underwater distance selected imaging. The respective imaging principle and characteristics are presented. Furthermore, the newest imaging technology, such as underwater compressive sensing imaging technology is described in detail. The recent researching status is included.

Underwater laser imaging experiments in the Baltic Sea

2014 ◽  
Author(s):  
Martin Laurenzis ◽  
Frank Christnacher ◽  
Thomas Scholz ◽  
Nicolas Metzger ◽  
Stefane Schertzer ◽  
...  
Keyword(s):  
Baltic Sea ◽  
The Baltic Sea ◽  
Laser Imaging ◽  
Underwater Laser ◽  
The Baltic

Results of the final tank test of the LLNL/NAVSEA synchronous-scanning underwater laser imaging system

1992 ◽  
Author(s):  
Thomas J. Kulp ◽  
Darrel G. Garvis ◽  
Randall B. Kennedy ◽  
Tom Salmon ◽  
Keith Cooper
Keyword(s):  
Imaging System ◽  
Laser Imaging ◽  
Tank Test ◽  
Underwater Laser
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