scholarly journals A Novel Low-Cost, High-Resolution Camera System for Measuring Peat Subsidence and Water Table Dynamics

2021 ◽  
Vol 9 ◽  
Author(s):  
Chris D. Evans ◽  
Nathan Callaghan ◽  
Adi Jaya ◽  
Alistair Grinham ◽  
Sofie Sjogersten ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Table ◽  
Large Scale ◽  
Low Cost ◽  
Ghg Emissions ◽  
Time Lapse ◽  
Surface Elevation ◽  
Carbon Loss ◽  
Camera System ◽  
Peat Surface

Peatlands are highly dynamic systems, able to accumulate carbon over millennia under natural conditions, but susceptible to rapid subsidence and carbon loss when drained. Short-term, seasonal and long-term peat surface elevation changes are closely linked to key peatland attributes such as water table depth (WTD) and carbon balance, and may be measured remotely using satellite radar and LiDAR methods. However, field measurements of peat elevation change are spatially and temporally sparse, reliant on low-resolution manual subsidence pole measurements, or expensive sensor systems. Here we describe a novel, simple and low-cost image-based method for measuring peat surface motion and WTD using commercially available time-lapse cameras and image processing methods. Based on almost two years’ deployment of peat cameras across contrasting forested, burned, agricultural and oil palm plantation sites in Central Kalimantan, Indonesia, we show that the method can capture extremely high resolution (sub-mm) and high-frequency (sub-daily) changes in peat surface elevation over extended periods and under challenging environmental conditions. WTD measurements were of similar quality to commercially available pressure transducers. Results reveal dynamic peat elevation response to individual rain events, consistent with variations in WTD. Over the course of the relatively severe 2019 dry season, cameras in deep-drained peatlands recorded maximum peat shrinkage of over 8 cm, followed by partial rebound, leading to net annual subsidence of up to 5 cm. Sites with higher water tables, and where borehole irrigation was used to maintain soil moisture, had lower subsidence, suggesting potential to reduce subsidence through altered land-management. Given the established link between subsidence and CO2 emissions, these results have direct implications for the management of peatlands to reduce high current greenhouse gas (GHG) emissions. Camera-based sensors provide a simple, low-cost alternative to commercial elevation, WTD and GHG flux monitoring systems, suitable for deployment at scale, and in areas where existing approaches are impractical or unaffordable. If ground-based observations of peat motion can be linked to measured GHG fluxes and with satellite-based monitoring tools, this approach offers the potential for a large-scale peatland monitoring tool, suitable for identifying areas of active carbon loss, targeting climate change mitigation interventions, and evaluating intervention outcomes.

A time-lapse seismic repeatability test using the P-Cable high-resolution 3D marine acquisition system

2020 ◽  
Vol 39 (7) ◽  
pp. 480-487
Author(s):  
Patrick Smith ◽  
Brandon Mattox
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Low Cost ◽  
Low Frequency ◽  
Time Lapse ◽  
Seismic Signal ◽  
Residual Energy ◽  
Acquisition System ◽  
Positioning Errors ◽  
Seismic Surveying

The P-Cable high-resolution 3D marine acquisition system tows many short, closely separated streamers behind a small source. It can provide 3D seismic data of very high temporal and spatial resolution. Since the system is containerized and has small dimensions, it can be deployed at short notice and relatively low cost, making it attractive for time-lapse seismic reservoir monitoring. During acquisition of a 3D high-resolution survey in the Gulf of Mexico in 2014, a pair of sail lines were repeated to form a time-lapse seismic test. We processed these in 2019 to evaluate their geometric and seismic repeatability. Geometric repetition accuracy was excellent, with source repositioning errors below 10 m and bin-based receiver positioning errors below 6.25 m. Seismic data comparisons showed normalized root-mean-square difference values below 10% between 40 and 150 Hz. Refinements to the acquisition system since 2014 are expected to further improve repeatability of the low-frequency components. Residual energy on 4D difference seismic data was low, and timing stability was good. We conclude that the acquisition system is well suited to time-lapse seismic surveying in areas where the reservoir and time-lapse seismic signal can be adequately imaged by small-source, short-offset, low-fold data.

Temperature evolution of an experimental salt-gradient solar pond

2010 ◽  
Vol 1 (4) ◽  
pp. 246-250 ◽  
Author(s):  
F. Suárez ◽  
A. E. Childress ◽  
S. W. Tyler
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Thermal Evolution ◽  
Low Cost ◽  
Heat Extraction ◽  
Low Grade ◽  
Distributed Temperature Sensing ◽  
Solar Pond ◽  
Thermal Desalination ◽  
Salt Gradient

A salt-gradient solar pond is a low-cost, large-scale solar collector with integrated storage that can be used as a source of energy in low-grade-heat thermal desalination systems. This work presents the thermal evolution of an experimental solar pond for both the maturation and heat extraction time periods. The temperature profile was measured every 1.1 cm using a vertical high-resolution distributed temperature sensing (DTS) system, with a temperature resolution of 0.04ºC. Temperatures of 34 and 45ºC were achieved in the bottom of the pond when the lights were on for 12 and 24 hours per day, respectively. Heat was extracted at a rate of 139 W from the solar pond, which corresponded to an efficiency of 29%. Stratification and mixing were clearly observed inside the solar pond using the vertical high-resolution DTS system.

scholarly journals Subsidence and carbon loss in drained tropical peatlands

2012 ◽  
Vol 9 (3) ◽  
pp. 1053-1071 ◽  
Author(s):  
A. Hooijer ◽  
S. Page ◽  
J. Jauhiainen ◽  
W. A. Lee ◽  
X. X. Lu ◽  
...  
Keyword(s):  
Water Table ◽  
Land Subsidence ◽  
Large Scale ◽  
Average Rate ◽  
Water Levels ◽  
First Year ◽  
Carbon Loss ◽  
Long Term Storage ◽  
Tropical Peatlands ◽  
Average Loss

Abstract. Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr−1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO2eq ha−1 yr−1, which reduced to 73 t CO2eq ha−1 yr−1 over subsequent years, potentially resulting in an average loss of 100 t CO2eq ha−1 yr−1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are inevitable consequences of conversion of forested tropical peatlands to other land uses.

Menu design approaches to promote sustainable vegetarian food choices when dining out

2021 ◽  
Author(s):  
Beth Parkin ◽  
Sophie Attwood
Keyword(s):  
Large Scale ◽  
Service Sector ◽  
Low Cost ◽  
Ghg Emissions ◽  
Food Service ◽  
Food Choices ◽  
Dietary Choices ◽  
Menu Design ◽  
Educational Campaigns ◽  
The Impact

Shifting dietary choices towards plant-based food is an urgent challenge given the environmental impact of livestock production and imminent need to reduce global greenhouse gas (GHG) emissions. Previous research has proven the value of low cost, scalable menu design interventions to influence people’s food choices, without the need for large-scale educational campaigns. Here we present two online randomized control trials to determine the effectiveness of menu design on nudging participants’ food choices away from meat and towards plant-based dishes, in order to provide guidance to the food service sector. In study one we explore the impact that the availability of vegetarian items has on choice. Participants were allocated to menus whereby 75%, 50% or 25% of the items were plant-based. We show that meat eaters were significantly more likely to choose a plant-based meal when presented with a menu where 75% of options were vegetarian, but not when half of the options were vegetarian. This finding highlights the fact that saturating the choice environment is needed to promote plant-based food. In study two, we explore the impact of vegetarian symbols (V) on menus to determine if these are used by meat eaters as exclusion decision filters, as is seen in previous work with menus that contain designated, ‘vegetarian’ dish sections. Here we show that the placement of the V symbol, to the left or right of the dish label, has no impact on choice. These studies provide insights into how the environmental footprint of the food service sector can be reduced via easy and scalable menu design approaches.

scholarly journals Point Cloud Stacking: A Workflow to Enhance 3D Monitoring Capabilities Using Time-Lapse Cameras

2020 ◽  
Vol 12 (8) ◽  
pp. 1240 ◽  
Author(s):  
Xabier Blanch ◽  
Antonio Abellan ◽  
Marta Guinau
Keyword(s):  
Point Cloud ◽  
Low Cost ◽  
Three Dimensional ◽  
Synthetic Data ◽  
Real Data ◽  
Point Clouds ◽  
Time Lapse ◽  
Position Estimation ◽  
Bundle Adjustment ◽  
Camera System

The emerging use of photogrammetric point clouds in three-dimensional (3D) monitoring processes has revealed some constraints with respect to the use of LiDAR point clouds. Oftentimes, point clouds (PC) obtained by time-lapse photogrammetry have lower density and precision, especially when Ground Control Points (GCPs) are not available or the camera system cannot be properly calibrated. This paper presents a new workflow called Point Cloud Stacking (PCStacking) that overcomes these restrictions by making the most of the iterative solutions in both camera position estimation and internal calibration parameters that are obtained during bundle adjustment. The basic principle of the stacking algorithm is straightforward: it computes the median of the Z coordinates of each point for multiple photogrammetric models to give a resulting PC with a greater precision than any of the individual PC. The different models are reconstructed from images taken simultaneously from, at least, five points of view, reducing the systematic errors associated with the photogrammetric reconstruction workflow. The algorithm was tested using both a synthetic point cloud and a real 3D dataset from a rock cliff. The synthetic data were created using mathematical functions that attempt to emulate the photogrammetric models. Real data were obtained by very low-cost photogrammetric systems specially developed for this experiment. Resulting point clouds were improved when applying the algorithm in synthetic and real experiments, e.g., 25th and 75th error percentiles were reduced from 3.2 cm to 1.4 cm in synthetic tests and from 1.5 cm to 0.5 cm in real conditions.

Testing of a Permanent Orbital Surface Source and Distributed Acoustic Sensing for monitoring of unconventional reservoirs: preliminary results from the Eagle Ford Shale

Geophysics ◽  
2020 ◽  
pp. 1-42
Author(s):  
Feng Cheng ◽  
Julia Correa ◽  
Shan Dou ◽  
Barry Freifeld ◽  
Todd Wood ◽  
...  
Keyword(s):  
High Resolution ◽  
Horizontal Well ◽  
Low Cost ◽  
Time Lapse ◽  
Unconventional Reservoirs ◽  
S Wave ◽  
Eagle Ford ◽  
Preliminary Results ◽  
Distributed Acoustic Sensing ◽  
High Repeatability

The effective monitoring of hydraulic fracturing in unconventional oil and gas production requires tools to quantify elastic property variations even in the absence of microseismic activity. To track the subtle time-lapse variations in reservoir properties during such activities, monitoring techniques with high repeatability and high resolution, both spatially and temporally, are required. Distributed Acoustic Sensing (DAS) is a rapidly maturing fiber-optic technology for low-cost, permanent, high density in-well monitoring. Surface Orbital Vibrators (SOVs) are an inexpensive fixed rotary seismic sources that offer the opportunity to frequently interrogate the subsurface with energies comparable to vibroseis sources. We present a field VSP test, conducted in the Eagle Ford play, pairing an SOV source recorded by DAS behind casing in a deviated well to better evaluate the potential of the technology set for unconventional reservoir monitoring. We demonstrate the data processing workflow for reservoir monitoring using SOV-DAS system. We analyze the data characteristics of SOV-DAS system, including S/N (signal to noise ratio) characteristics and source repeatability. High-quality P- and S- wave reflections, as well as mode conversions, are visible in the vertical section. In addition, clear P-P reflections are also observable along the horizontal well sections. Time-shifts with a mean value 10 μs between different datasets demonstrate the high repeatability for the semi-permanent SOV source, which is crucial for time-lapse analysis. We also apply reflection imaging on both P- and S- to reveal reflection depths. In a first-of-its-kind deployment, we implemented a rotating SOV with a slewing bearing and discuss the possibility to optimize S-wave construction along the horizontal well with specific SOV orientation directions. Our preliminary results show that the combination of repeatable surface sources such as SOVs with DAS has significant potential for providing a low-cost approach for high resolution seismic monitoring of unconventional reservoirs.

scholarly journals Optimised multi-camera systems for dimensional control in factory environments

2016 ◽  
Vol 232 (10) ◽  
pp. 1707-1718 ◽  
Author(s):  
Stuart Robson ◽  
Lindsay MacDonald ◽  
Stephen Kyle ◽  
Jan Boehm ◽  
Mark Shortis
Keyword(s):  
Large Scale ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Monochromatic Light ◽  
Test Methods ◽  
Small Scale ◽  
Tracking Accuracy ◽  
Camera Model ◽  
Dimensional Control ◽  
Camera System

As part of the United Kingdom’s Light Controlled Factory project, University College London aims to develop a large-scale multi-camera system for dimensional control tasks in manufacturing, such as part assembly and tracking. Accuracy requirements in manufacturing are demanding, and improvements in the modelling and analysis of both camera imaging and the measurement environment are essential. A major aspect to improved camera modelling is the use of monochromatic imaging of retro-reflective target points, together with a camera model designed for a particular illumination wavelength. A small-scale system for laboratory testing has been constructed using eight low-cost monochrome cameras with C-mount lenses on a rigid metal framework. Red, green and blue monochromatic light-emitting diode ring illumination has been tested, with a broadband white illumination for comparison. Potentially, accuracy may be further enhanced by the reduction in refraction errors caused by a non-homogeneous factory environment, typically manifest in varying temperatures in the workspace. A refraction modelling tool under development in the parallel European Union LUMINAR project is being used to simulate refraction in order to test methods which may be able to reduce or eliminate this effect in practice.

The First Large-Scale Offshore Aerial Survey Using a High-Resolution Camera System

2019 ◽  
pp. 115-123
Author(s):  
Stephanie McGovern ◽  
Julia Robinson Wilmott ◽  
Gregory Lampman ◽  
Ann Pembroke ◽  
Simon Warford ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Aerial Survey ◽  
Camera System

scholarly journals Development of high-resolution melting PCR (HRM-PCR) assay to identify native fungal species associated with the wheat endosphere

2020 ◽  
Vol 61 (4) ◽  
pp. 629-635
Author(s):  
Tomasz Cłapa ◽  
Katarzyna Mikołajczak ◽  
Lidia Błaszczyk ◽  
Dorota Narożna
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
High Resolution Melting ◽  
Low Cost ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Pcr Assay ◽  
Fungal Isolates ◽  
Large Scale Screening

Abstract Understanding the complexity and biodiversity of fungal communities associated with the wheat endosphere can facilitate the identification of novel strains that might be beneficial to the host plant. However, the differentiation and taxonomic classification of the endosphere-associated fungi with respect to various cultivars and plant organs are challenging, time-consuming, and expensive, even with the use of molecular techniques. In the present work, we describe a fast, simple, and low-cost method based on high-resolution melting PCR (HRM-PCR) for the identification and differentiation of wheat endogenous fungal isolates. Using this approach, we differentiated 28 fungal isolates, which belonged to five different genera, namely Alternaria, Penicillium, Epicoccum, Fusarium, and Trichoderma. Furthermore, the results of the study revealed that this method can allow large-scale screening of cultured samples.

Enhancements to Picosecond Acoustic Metrology for application in FO-WLP Process

2018 ◽  
Vol 2018 (1) ◽  
pp. 000212-000216
Author(s):  
M. Mehendale ◽  
R. Mair ◽  
J. Chen ◽  
J. Tan ◽  
J. Dai ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
Large Scale ◽  
Low Cost ◽  
Critical Role ◽  
Under Bump Metallization ◽  
Wafer Level ◽  
Wafer Level Packaging ◽  
Advanced Packaging ◽  
Line Space

Abstract Fan out wafer level packaging (FO-WLP) is one of the fastest growing advanced packaging segments due to its versatility for a wide variety of applications. It's compatibility with large scale, low cost, ultra-thin and high-density packages has made it very attractive. Cu redistribution layer and multiple metal under bump metallization stack play critical role in the FO-WLP process especially with shrinking line/space size and increasing density. We previously discussed the adaptation of PULSE™ technology, with the integration of a visible reflectometer and high resolution camera as a comprehensive in-line metrology tool for the advanced packaging applications. In this paper, we present results from some recent work on enhancements to the configuration for measurements of very thick, rough RDL films. The modifications provided significant improvement (9×) to throughput while maintaining gage capable repeatability. Cross-section SEM measurements on 1μm RDL structures were used to validate the extendibility of the technique.

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