scholarly journals Integrating UAVs and Canopy Height Models in Vineyard Management: A Time-Space Approach

2021 ◽  
Vol 14 (1) ◽  
pp. 130
Author(s):  
Alberto Sassu ◽  
Luca Ghiani ◽  
Luca Salvati ◽  
Luca Mercenaro ◽  
Alessandro Deidda ◽  
...  

The present study illustrates an operational approach estimating individual and aggregate vineyards’ canopy volume estimation through three years Tree-Row-Volume (TRV) measurements and remotely sensed imagery acquired with unmanned aerial vehicle (UAV) Red-Green-Blue (RGB) digital camera, processed with MATLAB scripts, and validated through ArcGIS tools. The TRV methodology was applied by sampling a different number of rows and plants (per row) each year with the aim of evaluating reliability and accuracy of this technique compared with a remote approach. The empirical results indicate that the estimated tree-row-volumes derived from a UAV Canopy Height Model (CHM) are up to 50% different from those measured on the field using the routinary technique of TRV in 2019. The difference is even much higher in the two 2016 dates. These empirical findings outline the importance of data integration among techniques that mix proximal and remote sensing in routine vineyards’ agronomic practices, helping to reduce management costs and increase the environmental sustainability of traditional cultivation systems.

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2182
Author(s):  
Baden Parr ◽  
Mathew Legg ◽  
Stuart Bradley ◽  
Fakhrul Alam

Grape yield estimation has traditionally been performed using manual techniques. However, these tend to be labour intensive and can be inaccurate. Computer vision techniques have therefore been developed for automated grape yield estimation. However, errors occur when grapes are occluded by leaves, other bunches, etc. Synthetic aperture radar has been investigated to allow imaging through leaves to detect occluded grapes. However, such equipment can be expensive. This paper investigates the potential for using ultrasound to image through leaves and identify occluded grapes. A highly directional low frequency ultrasonic array composed of ultrasonic air-coupled transducers and microphones is used to image grapes through leaves. A fan is used to help differentiate between ultrasonic reflections from grapes and leaves. Improved resolution and detail are achieved with chirp excitation waveforms and near-field focusing of the array. The overestimation in grape volume estimation using ultrasound reduced from 222% to 112% compared to the 3D scan obtained using photogrammetry or from 56% to 2.5% compared to a convex hull of this 3D scan. This also has the added benefit of producing more accurate canopy volume estimations which are important for common precision viticulture management processes such as variable rate applications.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1228
Author(s):  
Ting On Chan ◽  
Linyuan Xia ◽  
Yimin Chen ◽  
Wei Lang ◽  
Tingting Chen ◽  
...  

Ancient pagodas are usually parts of hot tourist spots in many oriental countries due to their unique historical backgrounds. They are usually polygonal structures comprised by multiple floors, which are separated by eaves. In this paper, we propose a new method to investigate both the rotational and reflectional symmetry of such polygonal pagodas through developing novel geometric models to fit to the 3D point clouds obtained from photogrammetric reconstruction. The geometric model consists of multiple polygonal pyramid/prism models but has a common central axis. The method was verified by four datasets collected by an unmanned aerial vehicle (UAV) and a hand-held digital camera. The results indicate that the models fit accurately to the pagodas’ point clouds. The symmetry was realized by rotating and reflecting the pagodas’ point clouds after a complete leveling of the point cloud was achieved using the estimated central axes. The results show that there are RMSEs of 5.04 cm and 5.20 cm deviated from the perfect (theoretical) rotational and reflectional symmetries, respectively. This concludes that the examined pagodas are highly symmetric, both rotationally and reflectionally. The concept presented in the paper not only work for polygonal pagodas, but it can also be readily transformed and implemented for other applications for other pagoda-like objects such as transmission towers.


2020 ◽  
pp. 1-15
Author(s):  
Sanna Saunaluoma ◽  
Justin Moat ◽  
Francisco Pugliese ◽  
Eduardo G. Neves

Our recent data, collected using remotely sensed imagery and unmanned aerial vehicle surveys, reveal the extremely well-defined patterning of archaeological plaza villages in the Brazilian Acre state in terms of size, layout, chronology, and material culture. The villages comprise various earthen mounds arranged around central plazas and roads that radiate outward from, or converge on, the sites. The roads connected the villages situated 2–10 km from each other in eastern Acre. Our study attests to the existence of large, sedentary, interfluvial populations sharing the same sociocultural identities, as well as structured patterns of movement and spatial planning in relation to operative road networks during the late precolonial period. The plaza villages of Acre show similarity with the well-documented communities organized by road networks in the regions of the Upper Xingu and Llanos de Mojos. Taking into consideration ethnohistorical and ethnographic evidence, as well as the presence of comparable archaeological sites and earthwork features along the southern margin of Amazonia, we suggest that the plaza villages of Acre were linked by an interregional road network to other neighboring territories situated along the southern Amazonian rim and that movement along roads was the primary mode of human transport in Amazonian interfluves.


2021 ◽  
Vol 13 (4) ◽  
pp. 656
Author(s):  
Xiang Zhang ◽  
Yuhai Bao ◽  
Dongliang Wang ◽  
Xiaoping Xin ◽  
Lei Ding ◽  
...  

The accurate estimation of grassland vegetation parameters at a high spatial resolution is important for the sustainable management of grassland areas. Unmanned aerial vehicle (UAV) light detection and ranging (LiDAR) sensors with a single laser beam emission capability can rapidly detect grassland vegetation parameters, such as canopy height, fractional vegetation coverage (FVC) and aboveground biomass (AGB). However, there have been few reports on the ability to detect grassland vegetation parameters based on RIEGL VUX-1 UAV LiDAR (Riegl VUX-1) systems. In this paper, we investigated the ability of Riegl VUX-1 to model the AGB at a 0.1 m pixel resolution in the Hulun Buir grazing platform under different grazing intensities. The LiDAR-derived minimum, mean, and maximum canopy heights and FVC were used to estimate the AGB across the entire grazing platform. The flight height of the LiDAR-derived vegetation parameters was also analyzed. The following results were determined: (1) The Riegl VUX-1-derived AGB was predicted to range from 29 g/m2 to 563 g/m2 under different grazing conditions. (2) The LiDAR-derived maximum canopy height and FVC were the best predictors of grassland AGB (R2 = 0.54, root-mean-square error (RMSE) = 64.76 g/m2). (3) For different UAV flight altitudes from 40 m to 110 m, different flight heights showed no major effect on the derived canopy height. The LiDAR-derived canopy height decreased from 9.19 cm to 8.17 cm, and the standard deviation of the LiDAR-derived canopy height decreased from 3.31 cm to 2.35 cm with increasing UAV flight altitudes. These conclusions could be useful for estimating grasslands in smaller areas and serving as references for other remote sensing datasets for estimating grasslands in larger areas.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ozgur Balli ◽  
Alper Dalkıran ◽  
Tahir Hikmet Karakoç

Purpose This study aims to investigate the aviation, energetic, exergetic, environmental, sustainability and exergoeconomic performances of a micro turbojet engine used in unmanned aerial vehicles at four different modes. Design/methodology/approach The engine data were collected from engine test cell. The engine performance calculations were performed for four different operation modes. Findings According to the results, maximum energy and exergy efficiency were acquired as 19.19% and 18.079% at Mode 4. Total cost rate was calculated as 6.757 $/h at Mode-1, which varied to 10.131 $/h at Mode-4. Exergy cost of engine power was observed as 0.249 $/MJ at Mode-1, which decreased to 0.088 $/MJ at Mode-4 after a careful exergoeconomic analysis. Originality/value The novelty of this work is the capability to serve as a guide for similar systems with a detailed approach in the thermodynamic, thermoeconomic and environmental assessments by prioritizing efficiency, fuel consumption and cost formation. This investigation intends to establish a design of the opportunities and benefits that the thermodynamic approach provides to turbojet engine systems.


Author(s):  
Ihor Ohirko ◽  
Zinovii Partyko

The problem of the truth of statements is considered. This study had the goal to develop a logical theory that would allow considering the context (the paradigm) from which would depend on the truth of the statement. For the development of such a theory, called the logic of relativity, the following methods of research are used as abstraction, analysis (traditional), synthesis, deduction, formalisation, axiomatisation, logical method. In order to develop the logic of relativity, it is expedient to use the achievements in the area of situational logic. Under the situation, it is proposed to understand two circumstances (time and space) and a condition that creates a context (paradigm) statement. Specifies the modal values that these three parameters can acquire and examines different types of situations. In order to write statements in the logic of relativity, a form of the statement of statements is proposed in the language of extended symbolic logic. For the theory of the logic of relativity, a set of four axioms is proposed and a series of laws. In particular, it is indicated that the values of the assertions in the logic of relativity are the following five estimates: truth, relative truth, relative is absurd, unclear, uncertain. Some theorems of the logic of relativity are proposed. A number of examples of texts in the natural language are given to interpret the statements of the logic of relativity. It is indicated that the proposed apparatus of the logic of relativity should be regarded as a kind of modal logic. The difference in the logic of relativity from situational logic is that it considers the factor of movement (motion) of statements in time, space and environment conditions, which was not considered by situational logic. The logic of relativity should be used wherever it is necessary to take into account the possibility of moving allegations regarding time, space and environment of conditions. One of the most important conclusions of the study is that in the logic to the standard values of truth (true, probably true, false, uncertain), it is expedient to add another value: relatively true (and accordingly: relatively false).


Author(s):  
M. Leslar

Using unmanned aerial vehicles (UAV) for the purposes of conducting high-accuracy aerial surveying has become a hot topic over the last year. One of the most promising means of conducting such a survey involves integrating a high-resolution non-metric digital camera with the UAV and using the principals of digital photogrammetry to produce high-density colorized point clouds. Through the use of stereo imagery, precise and accurate horizontal positioning information can be produced without the need for integration with any type of inertial navigation system (INS). Of course, some form of ground control is needed to achieve this result. Terrestrial LiDAR, either static or mobile, provides the solution. Points extracted from Terrestrial LiDAR can be used as control in the digital photogrammetry solution required by the UAV. In return, the UAV is an affordable solution for filling in the shadows and occlusions typically experienced by Terrestrial LiDAR. In this paper, the accuracies of points derived from a commercially available UAV solution will be examined and compared to the accuracies achievable by a commercially available LIDAR solution. It was found that the LiDAR system produced a point cloud that was twice as accurate as the point cloud produced by the UAV’s photogrammetric solution. Both solutions gave results within a few centimetres of the control field. In addition the about of planar dispersion on the vertical wall surfaces in the UAV point cloud was found to be multiple times greater than that from the horizontal ground based UAV points or the LiDAR data.


2018 ◽  
Vol 6 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Jungmok Ma

Abstract Proper modeling of the usage phase in Life Cycle Assessment (LCA) is not only critical due to its high impact among life cycle phases but also challenging due to high variations and uncertainty. Furthermore, when multiple products can be utilized, the optimal product usage should be considered together. The robust optimal usage modeling is proposed in this paper as the framework of usage modeling for LCA with consideration of the uncertainty and optimal usage. The proposed method seeks to optimal product usage in order to minimize the environmental impact of the usage phase under uncertainty. Numerical examples demonstrate the application of the robust optimal usage modeling and the difference from the previous approaches. Highlights The robust optimal usage modeling is proposed for the usage modeling of LCA. The proposed model seeks to sustainable product usage under uncertainty. Numerical examples demonstrate the difference from the previous approaches.


2021 ◽  
Author(s):  
Xin Lin ◽  
Chungan Li ◽  
Mei Zhou ◽  
Wenhai Liang ◽  
Biao Li

Abstract This study investigated the short-term spatial variability of an mangrove patch, located in the Pearl Bay in Guangxi, China. Unmanned aerial vehicle (UAV) imagery covering the period from March 2015 to October 2017 were used and the following models were developed: two annual ultra-high resolution spatial resolution digital orthophoto maps (DOMs), two digital elevation models (DEMs), two digital surface models (DSMs), two canopy height models (CHMs), and a canopy height difference model (d-CHM). Using these models, the spatial dynamics of the extent and canopy height of the patch were analyzed. The resolution of the DOMs was 0.1 m, with an average geometrical error of 0.17 m and a maximum error of 0.44 m. The resolutions of DEMs, DSMs, CHMs, d-CHM were all 1 m. The average elevation errors of CHM in 2015 and 2017 were 0.002 m and -0.001 m, respectively, with maximum absolute errors of 0.034 m and 0.030 m, respectively. The average elevation error of d-CHM was -0.003 m and the maximum absolute error was 0.036 m, and the data quality were rated as good. From 2015 to 2017, the area of the mangrove patch increased from 8.16 ha to 8.79 ha, with an average annual increase of 3.7%. Specifically, the areas of expansion, shrinkage, and maximum seaward expansion were 6356 m2, 19 m2, and 24 m, respectively. The driving factor for the variability was natural processes. Stand canopy height exhibited a particular trend of decrease from northwest to southeast (horizontal; parallel to the seawall) and from the land to the sea (vertically; perpendicular to the seawall). From 2015 to 2017, 88.2% of the patch area showed increased canopy height, with an average increase of 0.78 m and a maximum increase of 3.2 m. In contrast, 11.8% of the patch area showed decreased canopy height with a maximum decrease of 3.1 m. The main reason for the decrease in canopy height was the death of trees caused by serious insect plagues. On the other hand, the reason for the increase in height could be attributed to the natural growth of mangrove trees, but further studies are required to verify the cause. UAV remote sensing has an incomparable advantage over traditional methods in that it provides extremely detailed and highly accurate information for in-depth study of the spatial evolution of mangrove patches, which would significantly contribute towards the protection and management of mangroves.


2021 ◽  
pp. 50-58
Author(s):  
Michael Yu. Kataev ◽  
Maria M. Dadonova ◽  
Dmitry S. Efremenko

The goal of this research was to study and optimize multi-temporal RGB images obtained by a UAV (unmanned aerial vehicle). A digital camera onboard the UAV allows obtaining data with a high temporal and spatial resolution of ground objects. In the case considered by us, the object of study is agricultural fields, for which, based on numerous images covering the agricultural field, image mosaics (orthomosaics) are constructed. The acquisition time for each orthomosaic takes at least several hours, which imposes a change in the illuminance of each image, when considered separately. Orthomosaics obtained in different periods of the year (several months) will also differ from each other in terms of illuminance. For a comparative analysis of different parts of the field (orthomosaic), obtained in the same time interval or comparison of areas for different periods of time, their alignment by illumination is required. Currently, the majority of alignment approaches rely rather on colour (RGB) methods, which cannot guarantee finding efficient solutions, especially when it is necessary to obtain a quantitative result. In the paper, a new method is proposed that takes into account the change in illuminance during the acquisition of each image. The general formulation of the problem of light correction of RGB images in terms of assessing the colour vegetation index Greenness is considered. The results of processing real measurements are presented.


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