scholarly journals A Low-Cost Wireless Temperature Sensor: Evaluation for Use in Environmental Monitoring Applications

2014 ◽  
Vol 31 (4) ◽  
pp. 938-944 ◽  
Author(s):  
Duick T. Young ◽  
Lee Chapman ◽  
Catherine L. Muller ◽  
Xiao-Ming Cai ◽  
C. S. B. Grimmond
Keyword(s):  
Environmental Monitoring ◽  
Air Temperature ◽  
Urban Areas ◽  
Low Cost ◽  
Ambient Air ◽  
Platinum Resistance ◽  
Dense Network ◽  
Radiation Shield ◽  
Wide Range ◽  
Monitoring Applications

Abstract A wide range of environmental applications would benefit from a dense network of air temperature observations. However, with limitations of costs, existing siting guidelines, and risk of damage, new methods are required to gain a high-resolution understanding of spatiotemporal patterns of temperature for agricultural and urban meteorological phenomena such as the urban heat island. With the launch of a new generation of low-cost sensors, it is possible to deploy a network to monitor air temperature at finer spatial resolutions. This study investigates the Aginova Sentinel Micro (ASM) sensor with a custom radiation shield (together less than USD$150) that can provide secure near-real-time air temperature data to a server utilizing existing (or user deployed) Wi-Fi networks. This makes it ideally suited for deployment where wireless communications readily exist, notably urban areas. Assessment of the performance of the ASM relative to traceable standards in a water bath and atmospheric chamber show it to have good measurement accuracy with mean errors <±0.22°C between −25° and 30°C, with a time constant in ambient air of 110 ±15 s. Subsequent field tests also showed the ASM (in the custom shield) had excellent performance (RMSE = 0.13°C) over a range of meteorological conditions relative to a traceable operational Met Office platinum resistance thermometer. These results indicate that the ASM and radiation shield are more than fit for purpose for dense network deployment in environmental monitoring applications at relatively low cost compared to existing observation techniques.

scholarly journals Reducing post-harvest losses in fruits and vegetables for ensuring food security – Case of Sri Lanka

2021 ◽  
Vol 9 (1) ◽  
pp. 7-16
Author(s):  
Leelananda Rajapaksha ◽  
DMC Champathi Gunathilake ◽  
SM Pathirana ◽  
TN Fernando
Keyword(s):  
Food Security ◽  
Sri Lanka ◽  
Urban Areas ◽  
Low Cost ◽  
Economic Benefits ◽  
Fruit And Vegetables ◽  
Cold Chain ◽  
Small Scale ◽  
Post Harvest ◽  
Wide Range

In Sri Lanka, 70% of 21 million population live in non-urban areas, and agriculture provides livelihood for approximately 40% of them. The agricultural marketing process in the country is a complex operation due to services and functions involved in moving a crop product from where it was produced to where it would finally be consumed. Further, with a wide range of agricultural crops being produced, post-harvest handling process create different degrees of quantitative and qualitative losses in a complex market chain, which are estimated at 20% to 40% for vegetables and 30% - 40% for fruits. Improper and non-scientific post-harvest practices and handling, gaps in integration of cold chain practices & elements with post-harvest process, and lack of knowledge & awareness on many related aspects at grass root farmer level etc. appear to contribute to losses that finally prevent due economic benefits reaching the small-scale producer. In order to increase the effectiveness of post-harvest process handling of fruit and vegetables, appropriate corrective measures targeting small scale producers as well as commercial scale producers need to be popularized and practiced. At small scale producer level, promotion of appropriate low-cost post-harvest practices and procedures, facilitating low-cost cold chain elements and user-friendly information flow mechanism on market situation would certainly help avoid some of the steps that lead to losses. Monitoring system of commercial post-harvest handling process that ensure scientific bulk handling, storage and transportation of fruit and vegetables, properly designed economic centers with well regulated environmentcontrolled storages etc. would greatly reduce loses in bulk handling, ensuring better food security in the island.

scholarly journals DesPat: Smartphone-based Object Detection for Citizen Science and Urban Surveys

2021 ◽  
Author(s):  
Christopher Getschmann ◽  
Florian Echtler
Keyword(s):  
Data Collection ◽  
Object Detection ◽  
Citizen Science ◽  
Urban Areas ◽  
Low Cost ◽  
Traffic Patterns ◽  
Pedestrian Tracking ◽  
Privacy Concerns ◽  
Wide Range ◽  
Pedestrian Traffic

Data acquisition is a central task in research and one of the largest opportunities for citizen science. Especially in urban surveys investigating traffic and people flows, extensive manual labor is required, occasionally augmented by smartphones. We present DesPat, an app designed to turn a wide range of low-cost Android phones into a privacy-respecting camera-based pedestrian tracking tool to automatize data collection. This data can then be used to analyze pedestrian traffic patterns in general, and identify crowd hotspots and bottlenecks, which are particularly relevant in light of the recent COVID-19 pandemic.All image analysis is done locally on the device through a convolutional neural network, thereby avoiding any privacy concerns or legal issues regarding video surveillance. We show example heatmap visualizations from deployments of our prototype in urban areas and compare performance data for a variety of phones to discuss suitability of on-device object detection for our usecase of pedestrian data collection.

Characterization of Ambient Air Quality in Selected Urban Areas in Uganda: A Low-Cost Approach

2021 ◽  
Author(s):  
Deo Okure ◽  
Engineer Bainomugisha ◽  
Nancy Lozano-Gracia ◽  
Maria Edisa Soppelsa
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Low Cost ◽  
Ambient Air ◽  
Ambient Air Quality ◽  
Cost Approach

Automated detection of urban heat islands based on satellite imagery, digital surface models, and a low-cost sensor network                                     

2021 ◽  
Author(s):  
Sebastian Schlögl ◽  
Nico Bader ◽  
Julien Gérard Anet ◽  
Martin Frey ◽  
Curdin Spirig ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Rural Areas ◽  
Urban Areas ◽  
Low Cost ◽  
Urban Heat Islands ◽  
Heat Islands ◽  
Micro Scale ◽  
Air Temperatures ◽  
Urban Heat

<p>Today, more than half of the world’s population lives in urban areas and the proportion is projected to increase further in the near future. The increased number of heatwaves worldwide caused by the anthropogenic climate change may lead to heat stress and significant economic and ecological damages. Therefore, the growth of urban areas in combination with climate change can increase future mortality rates in cities, given that cities are more vulnerable to heatwaves due to the greater heat storage capacity of artificial surfaces towards higher longwave radiation fluxes.</p><p>To detect urban heat islands and resolve the micro-scale air temperature field in an urban environment, a low-cost air temperature network, including 450 sensors, was installed in the Swiss cities of Zurich and Basel in 2019 and 2020. These air temperature data, complemented with further official measurement stations, force a statistical air temperature downscaling model for urban environments, which is used operationally to calculate hourly micro-scale air temperatures in 10 m horizontal resolution. In addition to air temperature measurements from the low-cost sensor network, the model is further forced by albedo, NDVI, and NDBI values generated from the polar-orbiting satellite Sentinel-2, land surface temperatures estimated from Landsat-8, and high-resolution digital surface and elevation models.</p><p>Urban heat islands (UHI) are processed averaging hourly air temperatures over an entire year for each grid point, and comparing this average to the overall average in rural areas. UHI effects can then be correlated to high-resolution local climate zone maps and other local factors.</p><p>Between 60-80 % of the urban area is modeled with an accuracy below 1 K for an hourly time step indicating that the approach may work well in different cities. However, the outcome may depend on the complexity of the cities. The model error decreases rapidly by increasing the number of spatially distributed sensor data used to train the model, from 0 to 70 sensors, and then plateaus with further increases. An accuracy below 1 K can be expected for more than 50 air temperature measurements within the investigated cities and the surrounding rural areas. </p><p>A strong statistical air temperature model coupled with atmospheric boundary layer models (e.g. PALM-4U, MUKLIMO, FITNAH) will aid to generate highly resolved urban heat island prediction maps that help decision-makers to identify local heat islands easier. This will ensure that financial resources will be invested as efficiently as possible in mitigation actions.</p>

scholarly journals Study of novel solar assisted heating system

2021 ◽  
pp. 014362442110086
Author(s):  
Gareth Davies ◽  
John Blower ◽  
Richard Hall ◽  
Graeme Maidment
Keyword(s):  
Heat Pump ◽  
Solar Collector ◽  
Computer Modelling ◽  
Low Cost ◽  
Cost Savings ◽  
Ambient Air ◽  
Heat Pumps ◽  
Heating Systems ◽  
Collector Plate ◽  
Wide Range

The potential for energy, carbon dioxide equivalent (CO2e) and cost savings when using low emissivity (low-ε) transpired solar collectors (TSCs), combined with heat pumps in a range of configurations, has been investigated using computer modelling. Low-ε TSCs consist of metal solar collector plates with a spectrally sensitive surface, perforated with holes. Ambient air is drawn through the holes and heated by convection from the solar collector plate, increasing the air temperature by up to 25 K. The heated air can be used for e.g. space heating, or pre-heating water in buildings. The models developed have been used to compare the performance of low-ε TSC/heat pump heating systems in small and large buildings, at a range of locations. The model results showed savings in energy, CO2e and costs of up to 16.4% when using low-ε TSCs combined with an exhaust air heat pump compared with using the exhaust air heat pump alone. Practical application: If the UK is to meet its target of reaching net zero greenhouse gas emissions by 2050, it will be necessary to adopt low or zero carbon heating technologies. The novel low emissivity transpired solar collector device investigated can contribute to this. Its advantages include: (i) utilising solar radiation; (ii) readily integrated with existing heating systems e.g. heat pumps; (iii) significant energy, CO2e emissions and cost savings; (iv) low cost device; (v) minimal energy input i.e. one small fan; (vi) can be retrofitted to existing buildings; (vii) its benefits were applicable at all of the (wide range of) locations tested.

scholarly journals DesPat: Smartphone-Based Object Detection for Citizen Science and Urban Surveys

i-com ◽  
2021 ◽  
Vol 20 (2) ◽  
pp. 125-139
Author(s):  
Christopher Getschmann ◽  
Florian Echtler
Keyword(s):  
Data Collection ◽  
Object Detection ◽  
Citizen Science ◽  
Urban Areas ◽  
Low Cost ◽  
Traffic Patterns ◽  
Pedestrian Tracking ◽  
Privacy Concerns ◽  
Wide Range ◽  
Pedestrian Traffic

Abstract Data acquisition is a central task in research and one of the largest opportunities for citizen science. Especially in urban surveys investigating traffic and people flows, extensive manual labor is required, occasionally augmented by smartphones. We present DesPat, an app designed to turn a wide range of low-cost Android phones into a privacy-respecting camera-based pedestrian tracking tool to automatize data collection. This data can then be used to analyze pedestrian traffic patterns in general, and identify crowd hotspots and bottlenecks, which are particularly relevant in light of the recent COVID-19 pandemic. All image analysis is done locally on the device through a convolutional neural network, thereby avoiding any privacy concerns or legal issues regarding video surveillance. We show example heatmap visualizations from deployments of our prototype in urban areas and compare performance data for a variety of phones to discuss suitability of on-device object detection for our usecase of pedestrian data collection.

scholarly journals Effect of Relative Humidity and Air Temperature on the Results Obtained from Low-Cost Gas Sensors for Ambient Air Quality Measurements

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5175
Author(s):  
Abdul Samad ◽  
Daniel Ricardo Obando Nuñez ◽  
Grecia Carolina Solis Castillo ◽  
Bernd Laquai ◽  
Ulrich Vogt
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Data Quality ◽  
Air Temperature ◽  
Gas Sensors ◽  
Low Cost ◽  
Cost Effective ◽  
Ambient Air ◽  
Air Quality Measurements ◽  
Temperature Levels

Using low-cost gas sensors for air quality monitoring promises cost effective and convenient measurement systems. Nevertheless, the results obtained have a questionable quality due to different factors that can affect sensor performance. The most discussed ones are relative humidity and air temperature. This investigation aimed to assess the behavior of B4-series low-cost gas sensors from Alphasense for measuring CO, NO, NO2, and O3 for different levels of relative humidity and temperature. These low-cost gas sensors were tested for six relative humidity levels from 10% to 85% with increasing steps of 15% and four temperature levels of 10 °C, 25 °C, 35 °C, and 45 °C against reference instruments in the laboratory. The effect of these parameters on low-cost gas sensors was quantified in laboratory from which a correction algorithm was calculated, which was then applied to the field data. The applied algorithm improved the data quality of the low-cost gas sensors in most of the cases. Additionally, a low-cost dryer was assessed to reduce the influence of these factors on the low-cost gas sensors, which also proved to be suitable to enhance the data quality.

scholarly journals A Low-Cost Active Reflector for Interferometric Monitoring Based on Sentinel-1 SAR Images

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2008
Author(s):  
Guido Luzi ◽  
Pedro F. Espín-López ◽  
Fermín Mira Pérez ◽  
Oriol Monserrat ◽  
Michele Crosetto
Keyword(s):  
Urban Areas ◽  
Low Cost ◽  
Cost Benefit ◽  
Weather Conditions ◽  
Severe Weather ◽  
Synthetic Aperture ◽  
Stable Phase ◽  
Dense Network ◽  
Sar Images ◽  
Active Reflector

The effectiveness of radar interferometric techniques in non-urban areas can often be compromised due to the lack of stable natural targets. This drawback can be partially compensated through the installation of reference targets, characterized by a bright and stable radar response. The installation of passive corner reflectors (PCR) often represents a valid aid, but these objects are usually cumbersome, and suffer from severe weather conditions; furthermore, the installation of a PCR can be difficult and costly, especially in places with hard accessibility. Active reflectors (AR) represent a less cumbersome alternative to PCRs, while still providing a stable phase response. This paper describes the design, implementation, and test of an AR prototype, designed to operate with the Sentinel-1 synthetic aperture radar (SAR), aimed at providing a fair performance/cost benefit. These characteristics, obtained through a tradeoff between the use of off-the-shelf components and a simple architecture, can make the setup of a dense network (i.e., tens of devices) in the monitored areas feasible. The paper reports the design, implementation, and the analysis of different tests carried out in a laboratory, and in a real condition in the field, to illustrate AR reliability and estimate its phase stability.

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