scholarly journals Comparison of Different Analytical Strategies for Classifying Invasive Wetland Vegetation in Imagery from Unpiloted Aerial Systems (UAS)

2021 ◽  
Vol 13 (23) ◽  
pp. 4733
Author(s):  
Louis Will Jochems ◽  
Jodi Brandt ◽  
Andrew Monks ◽  
Megan Cattau ◽  
Nicholas Kolarik ◽  
...  
Keyword(s):  
Invasive Plants ◽  
Canopy Height ◽  
Surface Model ◽  
Wetland Ecosystems ◽  
Multispectral Data ◽  
Emergent Plants ◽  
Analysis Workflow ◽  
Analytical Strategies ◽  
And Control ◽  
Aerial Systems

Detecting newly established invasive plants is key to prevent further spread. Traditional field surveys are challenging and often insufficient to identify the presence and extent of invasions. This is particularly true for wetland ecosystems because of difficult access, and because floating and submergent plants may go undetected in the understory of emergent plants. Unpiloted aerial systems (UAS) have the potential to revolutionize how we monitor invasive vegetation in wetlands, but key components of the data collection and analysis workflow have not been defined. In this study, we conducted a rigorous comparison of different methodologies for mapping invasive Emergent (Typha × glauca (cattail)), Floating (Hydrocharis morsus-ranae (European frogbit)), and Submergent species (Chara spp. and Elodea canadensis) using the machine learning classifier, random forest, in a Great Lakes wetland. We compared accuracies using (a) different spatial resolutions (11 cm pixels vs. 3 cm pixels), (b) two classification approaches (pixel- vs. object-based), and (c) including structural measurements (e.g., surface/canopy height models and rugosity as textural metrics). Surprisingly, the coarser resolution (11 cm) data yielded the highest overall accuracy (OA) of 81.4%, 2.5% higher than the best performing model of the finer (3 cm) resolution data. Similarly, the Mean Area Under the Receiving Operations Characteristics Curve (AUROC) and F1 Score from the 11 cm data yielded 15.2%, and 6.5% higher scores, respectively, than those in the 3 cm data. At each spatial resolution, the top performing models were from pixel-based approaches and included surface model data over those with canopy height or multispectral data alone. Overall, high-resolution maps generated from UAS classifications will enable early detection and control of invasive plants. Our workflow is likely applicable to other wetland ecosystems threatened by invasive plants throughout the globe.

scholarly journals Mapping Canopy Heights of Poplar Plantations in Plain Areas Using ZY3-02 Stereo and Multispectral Data

2019 ◽  
Vol 8 (3) ◽  
pp. 106 ◽  
Author(s):  
Mingbo Liu ◽  
Chunxiang Cao ◽  
Wei Chen ◽  
Xuejun Wang
Keyword(s):  
Forest Canopy ◽  
Remote Sensing Data ◽  
Canopy Height ◽  
Coefficient Of Determination ◽  
Surface Model ◽  
Green Band ◽  
Entire Study ◽  
Multispectral Data ◽  
Poplar Plantations ◽  
Entire Study Area

Forest canopy height plays an important role in forest management and ecosystem modeling. There are a variety of techniques employed to map forest height using remote sensing data but it is still necessary to explore the use of new data and methods. In this study, we demonstrate an approach for mapping canopy heights of poplar plantations in plain areas through a combination of stereo and multispectral data from China’s latest civilian stereo mapping satellite ZY3-02. First, a digital surface model (DSM) was extracted using photogrammetry methods. Then, canopy samples and ground samples were selected through manual interpretation. Canopy height samples were obtained by calculating the DSM elevation differences between the canopy samples and ground samples. A regression model was used to correlate the reflectance of a ZY3-02 multispectral image with the canopy height samples, in which the red band and green band reflectance were selected as predictors. Finally, the model was extrapolated to the entire study area and a wall-to-wall forest canopy height map was obtained. The validation of the predicted canopy height map reported a coefficient of determination (R2) of 0.72 and a root mean square error (RMSE) of 1.58 m. This study demonstrates the capacity of ZY3-02 data for mapping the canopy height of pure plantations in plain areas.

ABOUT UNIFORMITY OF THE PHENOMENOLOGY AND THE MATHEMATICAL DESCRIPTION OF SO-CALLED « JOINED» ACTION OF HAZARDS AND COMBINED TOXICITY (ON THE EXAMPLE OF A COMBIBATION OF THE FLUORIDE AND THE STATIC MAGNETIC FIELD)

2016 ◽  
pp. 13-20
Author(s):  
B. A. Katsnelson ◽  
M. P. Sutunkova ◽  
N. A. Tsepilov ◽  
V. G. Panov ◽  
A. N. Varaksin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Point Of View ◽  
Whole Body ◽  
Surface Model ◽  
Combined Toxicity ◽  
Fluoride Solution ◽  
Adverse Action ◽  
Biochemical Indices ◽  
And Control

Sodium fluoride solution was injected i.p. to three groups of rats at a dose equivalent to 0.1 LD50 three times a week up to 18 injections. Two out of these groups and two out of three groups were sham-injected with normal saline and were exposed to the whole body impact of a 25 mT static magnetic field (SMF) for 2 or 4 hr a day, 5 times a week. Following the exposure, various functional and biochemical indices were evaluated along with histological examination and morphometric measurements of the femur in the differently exposed and control rats. The mathematical analysis of the combined effects of the SMF and fluoride based on the a response surface model demonstrated that, in full correspondence with what we had previously found for the combined toxicity of different chemicals, the combined adverse action of a chemical plus a physical agent was characterized by a tipological diversity depending not only on particular effects these types were assessed for but on the dose and effect levels as well. From this point of view, the indices for which at least one statistically significant effect was observed could be classified as identifying (I) mainly single-factor action; (II) additive unidirectional action; (III) synergism (superadditive unidirectional action); (IV) antagonism, including both subadditive unidirectional action and all variants of contradirectional action.

scholarly journals Use of TanDEM-X and SRTM-C Data for Detection of Deforestation Caused by Bark Beetle in Central European Mountains

2021 ◽  
Vol 13 (15) ◽  
pp. 3042
Author(s):  
Kateřina Gdulová ◽  
Jana Marešová ◽  
Vojtěch Barták ◽  
Marta Szostak ◽  
Jaroslav Červenka ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Synergistic Effects ◽  
Canopy Height ◽  
Surface Model ◽  
Multiple Time ◽  
Central European ◽  
Time Points ◽  
Bohemian Forest ◽  
Multiple Time Points ◽  
Surrounding Areas

The availability of global digital elevation models (DEMs) from multiple time points allows their combination for analysing vegetation changes. The combination of models (e.g., SRTM and TanDEM-X) can contain errors, which can, due to their synergistic effects, yield incorrect results. We used a high-resolution LiDAR-derived digital surface model (DSM) to evaluate the accuracy of canopy height estimates of the aforementioned global DEMs. In addition, we subtracted SRTM and TanDEM-X data at 90 and 30 m resolutions, respectively, to detect deforestation caused by bark beetle disturbance and evaluated the associations of their difference with terrain characteristics. The study areas covered three Central European mountain ranges and their surrounding areas: Bohemian Forest, Erzgebirge, and Giant Mountains. We found that vertical bias of SRTM and TanDEM-X, relative to the canopy height, is similar with negative values of up to −2.5 m and LE90s below 7.8 m in non-forest areas. In forests, the vertical bias of SRTM and TanDEM-X ranged from −0.5 to 4.1 m and LE90s from 7.2 to 11.0 m, respectively. The height differences between SRTM and TanDEM-X show moderate dependence on the slope and its orientation. LE90s for TDX-SRTM differences tended to be smaller for east-facing than for west-facing slopes, and varied, with aspect, by up to 1.5 m in non-forest areas and 3 m in forests, respectively. Finally, subtracting SRTM and NASA DEMs from TanDEM-X and Copernicus DEMs, respectively, successfully identified large areas of deforestation caused by hurricane Kyril in 2007 and a subsequent bark beetle disturbance in the Bohemian Forest. However, local errors in TanDEM-X, associated mainly with forest-covered west-facing slopes, resulted in erroneous identification of deforestation. Therefore, caution is needed when combining SRTM and TanDEM-X data in multitemporal studies in a mountain environment. Still, we can conclude that SRTM and TanDEM-X data represent suitable near global sources for the identification of deforestation in the period between the time points of their acquisition.

scholarly journals Controlling the Operation Process of the Unmanned Aerial System

2017 ◽  
Vol 44 (1) ◽  
pp. 5-36
Author(s):  
Leszek Ułanowicz ◽  
Michał Jóźko ◽  
Paweł Szczepaniak
Keyword(s):  
Technical Condition ◽  
Unmanned Aerial Systems ◽  
Unmanned Aerial System ◽  
Operation System ◽  
Mutual Relation ◽  
Operation Process ◽  
Credible Information ◽  
Technical Operation ◽  
And Control ◽  
Aerial Systems

Abstract The development of unmanned aerial systems (UAS) encountered the problem of controlling the process of technical operation. The literature that is available to the authors lacks credible information concerning the principles of specifying the strategy and control of the process of UAS operation. Hence, it is necessary to recognise and interpret the basic UAS operation features. The purpose of the publication is to present the properties of the UAS as an object of operation and the mutual relation of the technical operation process with the UAS’ technical condition alteration process. We present the results of analyses in terms of functionality and the UAS’ utility potential. The publication pays special attention to the properties of the UAS as an object of operation. The paper includes the analysis of the UAS operation principles and the specification of the advantage and disadvantage of those principles, i.e. using a non-repairable UAS until damaged, using a repairable UAS until damaged, periodical technical servicing, continuous diagnostic operation. The proposals for the control models in the UAS operation system have also been included.

Unmanned aerial systems: autonomy, cognition, and control

2021 ◽  
pp. 47-80
Author(s):  
Allahyar Montazeri ◽  
Aydin Can ◽  
Imil Hamda Imran
Keyword(s):  
Unmanned Aerial Systems ◽  
And Control ◽  
Aerial Systems

scholarly journals Development of Digital Subterranean Models for Real-Time Open Cut Horizon Control

Resources ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 50
Author(s):  
Andrew D. Strange ◽  
Zak Jecny
Keyword(s):  
Technology Development ◽  
Surface Model ◽  
Prototype System ◽  
Mining Operations ◽  
Digital Mine ◽  
Sensing System ◽  
Mining Machinery ◽  
Strong Motivation ◽  
Ground Penetrating ◽  
And Control

A reliable coal seam sensing system is required to improve the productivity of selective mining in open-cut mining operations. A prototype system based upon commercial ground penetrating radar equipment, which measures coal thickness from the top of an exposed surface down to an underlying coal-interburden interface and generates digital subterranean models of the subsurface seam boundaries, was developed for this purpose. The models can be deployed to commercially available in-cab assistive guidance systems for bulldozers and other mining machinery in existing production processes, and can further contribute to the databases required for remote operation and control in a complete digital mine scenario. The system was evaluated at a production open cut coal mine in Queensland, Australia, with promising results. The benefits reported by operational personnel who evaluated the digital surface model in the mining environment provide strong motivation for ongoing technology development.

scholarly journals Measuring Height Characteristics of Sagebrush (Artemisia sp.) Using Imagery Derived from Small Unmanned Aerial Systems (sUAS)

Drones ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 6 ◽  
Author(s):  
Ryan G. Howell ◽  
Ryan R. Jensen ◽  
Steven L. Petersen ◽  
Randy T. Larsen
Keyword(s):  
Data Storage ◽  
Accuracy Assessment ◽  
Point Clouds ◽  
Unmanned Aerial Systems ◽  
Surface Model ◽  
Sage Grouse ◽  
Double Pass ◽  
Single Pass ◽  
3D Point Clouds ◽  
Aerial Systems

In situ measurements of sagebrush have traditionally been expensive and time consuming. Currently, improvements in small Unmanned Aerial Systems (sUAS) technology can be used to quantify sagebrush morphology and community structure with high resolution imagery on western rangelands, especially in sensitive habitat of the Greater sage-grouse (Centrocercus urophasianus). The emergence of photogrammetry algorithms to generate 3D point clouds from true color imagery can potentially increase the efficiency and accuracy of measuring shrub height in sage-grouse habitat. Our objective was to determine optimal parameters for measuring sagebrush height including flight altitude, single- vs. double- pass, and continuous vs. pause features. We acquired imagery using a DJI Mavic Pro 2 multi-rotor Unmanned Aerial Vehicle (UAV) equipped with an RGB camera, flown at 30.5, 45, 75, and 120 m and implementing single-pass and double-pass methods, using continuous flight and paused flight for each photo method. We generated a Digital Surface Model (DSM) from which we derived plant height, and then performed an accuracy assessment using on the ground measurements taken at the time of flight. We found high correlation between field measured heights and estimated heights, with a mean difference of approximately 10 cm (SE = 0.4 cm) and little variability in accuracy between flights with different heights and other parameters after statistical correction using linear regression. We conclude that higher altitude flights using a single-pass method are optimal to measure sagebrush height due to lower requirements in data storage and processing time.

scholarly journals Estimating Pasture Biomass and Canopy Height in Brazilian Savanna Using UAV Photogrammetry

2019 ◽  
Vol 11 (20) ◽  
pp. 2447 ◽  
Author(s):  
Juliana Batistoti ◽  
José Marcato Junior ◽  
Luís Ítavo ◽  
Edson Matsubara ◽  
Eva Gomes ◽  
...  
Keyword(s):  
Digital Terrain Model ◽  
Technical Note ◽  
Canopy Height ◽  
Brazilian Savanna ◽  
Surface Model ◽  
Panicum Maximum ◽  
Ground Sample ◽  
Terrain Model ◽  
Sampling Height ◽  
The Difference

The Brazilian territory contains approximately 160 million hectares of pastures, and it is necessary to develop techniques to automate their management and increase their production. This technical note has two objectives: First, to estimate the canopy height using unmanned aerial vehicle (UAV) photogrammetry; second, to propose an equation for the estimation of biomass of Brazilian savanna (Cerrado) pastures based on UAV canopy height. Four experimental units of Panicum maximum cv. BRS Tamani were evaluated. Herbage mass sampling, height measurements, and UAV image collection were simultaneously performed. The UAVs were flown at a height of 50 m, and images were generated with a mean ground sample distance (GSD) of approximately 1.55 cm. The forage canopy height estimated by UAVs was calculated as the difference between the digital surface model (DSM) and the digital terrain model (DTM). The R2 between ruler height and UAV height was 0.80; between biomass (kg ha−1 GB—green biomass) and ruler height, 0.81; and between biomass (kg ha−1 GB) and UAV height, 0.74. UAV photogrammetry proved to be a potential technique to estimate height and biomass in Brazilian Panicum maximum cv. BRS Tamani pastures located in the endangered Brazilian savanna (Cerrado) biome.

scholarly journals METHODS FOR THE UPDATE AND VERIFICATION OF FOREST SURFACE MODEL

2016 ◽  
Vol XLI-B4 ◽  
pp. 51-54
Author(s):  
M. Rybansky ◽  
M. Brenova ◽  
P. Zerzan ◽  
J. Simon ◽  
T. Mikita
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Geographic Location ◽  
Canopy Height ◽  
Aerial Photographs ◽  
Surface Model ◽  
Vegetation Growth ◽  
Terrain Model ◽  
Digital Terrain ◽  
Pulse Echo

The digital terrain model (DTM) represents the bare ground earth's surface without any objects like vegetation and buildings. In contrast to a DTM, Digital surface model (DSM) represents the earth's surface including all objects on it. The DTM mostly does not change as frequently as the DSM. The most important changes of the DSM are in the forest areas due to the vegetation growth. Using the LIDAR technology the canopy height model (CHM) is obtained by subtracting the DTM and the corresponding DSM. The DSM is calculated from the first pulse echo and DTM from the last pulse echo data. The main problem of the DSM and CHM data using is the actuality of the airborne laser scanning. <br><br> This paper describes the method of calculating the CHM and DSM data changes using the relations between the canopy height and age of trees. To get a present basic reference data model of the canopy height, the photogrammetric and trigonometric measurements of single trees were used. Comparing the heights of corresponding trees on the aerial photographs of various ages, the statistical sets of the tree growth rate were obtained. These statistical data and LIDAR data were compared with the growth curve of the spruce forest, which corresponds to a similar natural environment (soil quality, climate characteristics, geographic location, etc.) to get the updating characteristics.

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