Multitemporal Chlorophyll Mapping in Pome Fruit Orchards from Remotely Piloted Aircraft Systems

Early and precise spatio-temporal monitoring of tree vitality is key for steering management decisions in pome fruit orchards. Spaceborne remote sensing instruments face a tradeoff between spatial and spectral resolution, while manned aircraft sensor-platform systems are very expensive. In order to address the shortcomings of these platforms, this study investigates the potential of Remotely Piloted Aircraft Systems (RPAS) to facilitate rapid, low cost, and flexible chlorophyll monitoring. Due to the complexity of orchard scenery a robust chlorophyll retrieval model on RPAS level has not yet been developed. In this study, specific focus therefore lies on evaluating the sensitivity of retrieval models to confounding factors. For this study, multispectral and hyperspectral imagery was collected over pome fruit orchards. Sensitivities of both univariate and multivariate retrieval models were demonstrated under different species, phenology, shade, and illumination scenes. Results illustrate that multivariate models have a significantly higher accuracy than univariate models as the former provide accuracies for the canopy chlorophyll content retrieval of R2 = 0.80 and Relative Root Mean Square Error (RRMSE) = 12% for the hyperspectral sensor. Random forest regression on multispectral imagery (R2 > 0.9 for May, June, July, and August, and R2 = 0.5 for October) and hyperspectral imagery (0.6 < R2 < 0.9) led to satisfactory high and consistent accuracies for all months.

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Long-endurance remotely piloted aircraft systems (LE-RPAS) support for humanitarian logistic operations

Journal of Humanitarian Logistics and Supply Chain Management ◽

10.1108/jhlscm-05-2016-0018 ◽

2017 ◽

Vol 7 (1) ◽

pp. 2-25 ◽

Cited By ~ 13

Author(s):

Peter Tatham ◽

Catherine Ball ◽

Yong Wu ◽

Peter Diplas

Keyword(s):

Low Cost ◽

Rapid Onset ◽

Limited Range ◽

Formal Proof ◽

Military Operations ◽

Content Type ◽

Aircraft Systems ◽

Remotely Piloted Aircraft ◽

Long Endurance ◽

The Impact

Purpose While the use of long-endurance remotely piloted aircraft systems (LE-RPAS) is frequently associated with military operations, their core capabilities of long-range, low-cost and high-quality optics and communications systems have considerable potential benefit in supporting the work of humanitarian logisticians. The purpose of this paper is, therefore, to demonstrate how LE-RPAS could be used to improve the logistic response to a rapid onset disaster. Design/methodology/approach Using the response to the Cyclone Pam that struck Vanuatu in March 2015 as an example, this paper provides an overview of how LE-RPAS could be used to support the post-disaster needs assessment and subsequent response processes. In addition, it provides a high-level route map to develop the people, process and technology requirements that would support the operational deployment of the LE-RPAS capabilities. Findings On the basis of the analysis of the published literature and the resultant assessment of the benefits of LE-RPAS to support humanitarian logistic (HL) operations, it is concluded that a formal “proof of concept” trial should be undertaken, and the results be made available to the humanitarian community. Research limitations/implications This paper is conceptual in nature, but has been developed through an analysis of the literature relating to remotely piloted aircraft systems (RPAS) and HLs. A route map through which the paper’s conclusions can be validated is also offered. Practical implications LE-RPAS have great potential to provide a swifter understanding of the impact of a disaster, particularly those where the location is remote from the main centres of population. This would allow the affected country’s National Disaster Management Organisation, together with those of supporting countries, to react more efficiently and effectively. In particular, it would allow a swifter transition from a “guess-based” push approach to one that more accurately reflects the disaster’s impact – i.e. a pull-based logistic response. Social implications Given the military genesis of RPAS, it will be important to ensure that those engaged in their operation are sensitive to the implications of this. In particular, it will be essential to ensure that any humanitarian operations involving RPAS are undertaken in an ethical way that respects, for example, the privacy and safety of the affected population. Originality/value While there is some emerging discussion on the humanitarian-related use of RPAS in the literature, this generally reflects the operation of small aircraft with limited range and payload capabilities. Useful though such RPAS unquestionably are, this paper expands the discussion of how such systems can support the humanitarian logistician by considering the benefits and challenges of operating long-endurance aircraft.

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Terrain Draping and Following Using Low-Cost Remotely Piloted Aircraft Systems for Geophysical Survey Applications

10.22215/etd/2020-13904 ◽

2020 ◽

Author(s):

Salman Shafi

Keyword(s):

Low Cost ◽

Geophysical Survey ◽

Aircraft Systems ◽

Remotely Piloted Aircraft

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Detailed Characterization and Monitoring of a Retrogressive Thaw Slump from Remotely Piloted Aircraft Systems and Identifying Associated Influence on Carbon and Nitrogen Export

Remote Sensing ◽

10.3390/rs13020171 ◽

2021 ◽

Vol 13 (2) ◽

pp. 171

Author(s):

Kevin W. Turner ◽

Michelle D. Pearce ◽

Daniel D. Hughes

Keyword(s):

Surface Model ◽

Carbon And Nitrogen ◽

Aircraft Systems ◽

Detailed Classification ◽

Fill Volume ◽

Remotely Piloted Aircraft ◽

Total Irradiance ◽

Retrogressive Thaw Slump ◽

Rain Events ◽

Sediment Export

Ice-rich permafrost landscapes are sensitive to ongoing changes in climate. Permafrost retrogressive thaw slumps (RTSs) represent one of the more abrupt and prolonged disturbances, which occur along Arctic river and lake shorelines. These features impact local travel and infrastructure, and there are many questions regarding associated impacts on biogeochemical cycling. Predicting the duration and magnitude of impacts requires that we enhance our knowledge of RTS geomorphological drivers and rates of change. Here we demonstrate the utility of remotely piloted aircraft systems (RPAS) for documenting the volumetric change, associated drivers and potential impacts of the largest active RTS along the Old Crow River in Old Crow Flats, Yukon, Canada. RPAS surveys revealed that 29,174 m3 of sediment was exported during the initial evacuation in June 2016 and an additional 18,845 m3 continued to be exported until June 2019. More sediment export occurred during the warmer 2017 summer that experienced less cumulative rainfall than summer 2018. However, several rain events during 2017 were of higher intensity than during 2018. Overall mean soil organic carbon (SOC) and total nitrogen (TN) within sampled thaw slump sediment was 1.36% and 0.11%, respectively. A combination of multispectral, thermal and irradiance (derived from the RPAS digital surface model) data provided detailed classification of thaw slump floor terrain types including raised dry clay lobes, shaded and relatively stable, and low-lying evacuation-prone sediments. Notably, the path of evacuation-prone sediments extended to a series of ice wedges in the northern headwall, where total irradiance was highest. Using thaw slump floor mean SOC and TN values in conjunction with sediment bulk density and thaw slump fill volume, we estimated that 713 t SOC and 58 t TN were exported to the Old Crow River during the three-year study. Findings showcase the utility of high-resolution RPAS datasets for refining our knowledge of thaw slump geomorphology and associated impacts.

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Biomechanics of Trail Running Performance: Quantification of Spatio-Temporal Parameters by Using Low Cost Sensors in Ecological Conditions

Applied Sciences ◽

10.3390/app11052093 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2093

Author(s):

Noé Perrotin ◽

Nicolas Gardan ◽

Arnaud Lesprillier ◽

Clément Le Goff ◽

Jean-Marc Seigneur ◽

...

Keyword(s):

Heart Rate ◽

Low Cost ◽

Step Length ◽

Measurement Unit ◽

Ecological Conditions ◽

Sports Science ◽

Ground Contact Time ◽

Spatio Temporal ◽

Performance Results ◽

Trail Running

The recent popularity of trail running and the use of portable sensors capable of measuring many performance results have led to the growth of new fields in sports science experimentation. Trail running is a challenging sport; it usually involves running uphill, which is physically demanding and therefore requires adaptation to the running style. The main objectives of this study were initially to use three “low-cost” sensors. These low-cost sensors can be acquired by most sports practitioners or trainers. In the second step, measurements were taken in ecological conditions orderly to expose the runners to a real trail course. Furthermore, to combine the collected data to analyze the most efficient running techniques according to the typology of the terrain were taken, as well on the whole trail circuit of less than 10km. The three sensors used were (i) a Stryd sensor (Stryd Inc. Boulder CO, USA) based on an inertial measurement unit (IMU), 6 axes (3-axis gyroscope, 3-axis accelerometer) fixed on the top of the runner’s shoe, (ii) a Global Positioning System (GPS) watch and (iii) a heart belt. Twenty-eight trail runners (25 men, 3 women: average age 36 ± 8 years; height: 175.4 ± 7.2 cm; weight: 68.7 ± 8.7 kg) of different levels completed in a single race over a 8.5 km course with 490 m of positive elevation gain. This was performed with different types of terrain uphill (UH), downhill (DH), and road sections (R) at their competitive race pace. On these sections of the course, cadence (SF), step length (SL), ground contact time (GCT), flight time (FT), vertical oscillation (VO), leg stiffness (Kleg), and power (P) were measured with the Stryd. Heart rate, speed, ascent, and descent speed were measured by the heart rate belt and the GPS watch. This study showed that on a ≤10 km trail course the criteria for obtaining a better time on the loop, determined in the test, was consistency in the effort. In a high percentage of climbs (>30%), two running techniques stand out: (i) maintaining a high SF and a short SL and (ii) decreasing the SF but increasing the SL. In addition, it has been shown that in steep (>28%) and technical descents, the average SF of the runners was higher. This happened when their SL was shorter in lower steep and technically challenging descents.

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Spectral Complexity of Hyperspectral Images: A New Approach for Mangrove Classification

Remote Sensing ◽

10.3390/rs13132604 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2604

Author(s):

Patrick Osei Darko ◽

Margaret Kalacska ◽

J. Pablo Arroyo-Mora ◽

Matthew E. Fagan

Keyword(s):

Statistical Physics ◽

Near Infrared ◽

Information Gain ◽

Hyperspectral Imagery ◽

Full Range ◽

Surface Reflectance ◽

Mangrove Species ◽

New Approach ◽

Spatio Temporal ◽

Shortwave Infrared

Hyperspectral remote sensing across multiple spatio-temporal scales allows for mapping and monitoring mangrove habitats to support urgent conservation efforts. The use of hyperspectral imagery for assessing mangroves is less common than for terrestrial forest ecosystems. In this study, two well-known measures in statistical physics, Mean Information Gain (MIG) and Marginal Entropy (ME), have been adapted to high spatial resolution (2.5 m) full range (Visible-Shortwave-Infrared) airborne hyperspectral imagery. These two spectral complexity metrics describe the spatial heterogeneity and the aspatial heterogeneity of the reflectance. In this study, we compare MIG and ME with surface reflectance for mapping mangrove extent and species composition in the Sierpe mangroves in Costa Rica. The highest accuracy for separating mangroves from forest was achieved with visible-near infrared (VNIR) reflectance (98.8% overall accuracy), following by shortwave infrared (SWIR) MIG and ME (98%). Our results also show that MIG and ME can discriminate dominant mangrove species with higher accuracy than surface reflectance alone (e.g., MIG–VNIR = 93.6% vs. VNIR Reflectance = 89.7%).

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Use of Remotely Piloted Aircraft Systems in Arctic and comparable extreme environments in civil security scenarios

2015 Second International Conference on Computer Science, Computer Engineering, and Social Media (CSCESM) ◽

10.1109/cscesm.2015.7331894 ◽

2015 ◽

Author(s):

Kaci Bourdache ◽

Tina El-Nemr

Keyword(s):

Extreme Environments ◽

Aircraft Systems ◽

Remotely Piloted Aircraft

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How low-cost air pollution sensors could make homes smarter?

10.5194/egusphere-egu21-9113 ◽

2021 ◽

Author(s):

Hamid Omidvarborna ◽

Prashant Kumar

Keyword(s):

Air Pollution ◽

Indoor Air ◽

Air Pollutants ◽

Indoor Air Pollution ◽

Prediction Models ◽

Disease Risk ◽

Low Cost ◽

Mortality And Morbidity ◽

Spatio Temporal ◽

Indoor Air Pollutants

<p>The majority of people spend most of their time indoors, where they are exposed to indoor air pollutants. Indoor air pollution is ranked among the top ten largest global burden of a disease risk factor as well as the top five environmental public health risks, which could result in mortality and morbidity worldwide. The spent time in indoor environments has been recently elevated due to coronavirus disease 2019 (COVID-19) outbreak when the public are advised to stay in their place for longer hours per day to protect lives. This opens an opportunity to low-cost air pollution sensors in the real-time Spatio-temporal mapping of IAQ and monitors their concentration/exposure levels indoors. However, the optimum selection of low-cost sensors (LCSs) for certain indoor application is challenging due to diversity in the air pollution sensing device technologies. Making affordable sensing units composed of individual sensors capable of measuring indoor environmental parameters and pollutant concentration for indoor applications requires a diverse scientific and engineering knowledge, which is not yet established. The study aims to gather all these methodologies and technologies in one place, where it allows transforming typical homes into smart homes by specifically focusing on IAQ. This approach addresses the following questions: 1) which and what sensors are suitable for indoor networked application by considering their specifications and limitation, 2) where to deploy sensors to better capture Spatio-temporal mapping of indoor air pollutants, while the operation is optimum, 3) how to treat the collected data from the sensor network and make them ready for the subsequent analysis and 4) how to feed data to prediction models, and which models are best suited for indoors.</p>

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Intra-annual and intra-seasonal flow dynamics of a High Arctic polythermal valley glacier

Annals of Glaciology ◽

10.3189/172756403781815762 ◽

2003 ◽

Vol 37 ◽

pp. 181-188 ◽

Cited By ~ 42

Author(s):

Robert G. Bingham ◽

Peter W. Nienow ◽

Martin J. Sharp

Keyword(s):

Drainage System ◽

High Arctic ◽

Ablation Zone ◽

Accumulation Zone ◽

Seasonal Flow ◽

Excess Surface ◽

Velocity Response ◽

Spatio Temporal ◽

June July ◽

Arctic Glacier

AbstractMeasurements of surface dynamics on polythermal John Evans Glacier, Nunavut, Canada, over two winter periods and every 7–10 days throughout two melt seasons (June–July 2000, 2001) provide new insight into spatio-temporal patterns of High Arctic glacier dynamics. In the lower ablation zone, mean annual surface velocities are 10–21 m a–1, but peak velocities up to 50% higher are attained during late June/early July. In the upper ablation zone and lower accumulation zone, mean annual surface velocities are typically 10–18 m a–1, and peak velocities up to 40% higher occur during late July. In the upper accumulation zone, mean annual surface velocities are 2–9 m a–1, and motion in mid- to late July exceeds this by up to 10%. Rapid drainage of ponded supraglacial water in the upper ablation zone to an initially distributed subglacial drainage system in mid-June may force excess surface motion in the warm-based lower glacier. The data indicate that the duration of the velocity response may be related to the rate of channelization of the basal drainage, and the velocity response may be transmitted up-glacier by longitudinal coupling. An increase in surface velocities in the middle glacier in late July occurs in conjunction with the opening of two further moulins in the accumulation zone.

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