Preliminary analysis of the forest health state based on multispectral images acquired by Unmanned Aerial Vehicle (original) (raw)

Use of a Multispectral Uav Photogrammetry for Detection and Tracking of Forest Disturbance Dynamics

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016

This study presents a new methodological approach for assessment of spatial and qualitative aspects of forest disturbance based on the use of multispectral imaging camera with the UAV photogrammetry. We have used the miniaturized multispectral sensor Tetracam Micro Multiple Camera Array (μ-MCA) Snap 6 with the multirotor imaging platform to get multispectral imagery with high spatial resolution. The study area is located in the Sumava Mountains, Central Europe, heavily affected by windstorms, followed by extensive and repeated bark beetle (Ips typographus [L.]) outbreaks in the past 20 years. After two decades, there is apparent continuous spread of forest disturbance as well as rapid regeneration of forest vegetation, related with changes in species and their diversity. For testing of suggested methodology, we have launched imaging campaign in experimental site under various stages of forest disturbance and regeneration. The imagery of high spatial and spectral resolution enabled t...

International Journal of Conservation Science Forest Monitoring Method Using Combinations of Satellite and Uav Aerial Images. Case Study-Bălăbăneşti Forest

The increasing use of satellite faraway sensing for civilian use has proved to be the most cost effective means of mapping and monitoring environmental changes. From this point of view, these new tools are now essential in monitoring operations for vegetation and non-renewable resources, especially in developing countries. In today's literature a series of 262 spectral indices are defined to evaluate the vegetation health for a specific area. For the vast majority of these infrared spectral index values are included. Infrared recording devices are quite expensive. In this respect, the possibility of using only the visible domain should be experienced in order to reduce the operational costs. The main hypothesis comes from the fact that any changes in vegetation status cannot be reduced and described only by the infrared domain changes. This study presents the results of a general aim: to design, to investigate and to confirm a specific analysis method that uses only the visible ...

Monitoring Fine-Scale Forest Health Using Unmanned Aerial Systems (UAS) Multispectral Models

Remote Sensing, 2021

Forest disturbances—driven by pests, pathogens, and discrete events—have led to billions of dollars in lost ecosystem services and management costs. To understand the patterns and severity of these stressors across complex landscapes, there must be an increase in reliable data at scales compatible with management actions. Unmanned aerial systems (UAS or UAV) offer a capable platform for collecting local scale (e.g., individual tree) forestry data. In this study, we evaluate the capability of UAS multispectral imagery and freely available National Agricultural Imagery Program (NAIP) imagery for differentiating coniferous healthy, coniferous stressed, deciduous healthy, deciduous stressed, and degraded individual trees throughout a complex, mixed-species forests. These methods are first compared to assessments of crown vigor in the field, to evaluate the potential in supplementing this resource intensive practice. This investigation uses the random forest and support vector machine (S...

Forestry Remote Sensing from Unmanned Aerial Vehicles: A Review Focusing on the Data, Processing and Potentialities

Remote Sensing, 2020

Currently, climate change poses a global threat, which may compromise the sustainability of agriculture, forestry and other land surface systems. In a changing world scenario, the economic importance of Remote Sensing (RS) to monitor forests and agricultural resources is imperative to the development of agroforestry systems. Traditional RS technologies encompass satellite and manned aircraft platforms. These platforms are continuously improving in terms of spatial, spectral, and temporal resolutions. The high spatial and temporal resolutions, flexibility and lower operational costs make Unmanned Aerial Vehicles (UAVs) a good alternative to traditional RS platforms. In the management process of forests resources, UAVs are one of the most suitable options to consider, mainly due to: (1) low operational costs and high-intensity data collection; (2) its capacity to host a wide range of sensors that could be adapted to be task-oriented; (3) its ability to plan data acquisition campaigns,...

Evaluation of UAS flight parameters for rapid monitoring of forest characteristics

Colorado State University. Libraries, 2019

EVALUATION OF UAS FLIGHT PARAMETERS FOR RAPID MONITORING OF FOREST CHARACTERISTICS Forest managers are increasingly turning to finer spatial and temporal resolution data for monitoring forest structure in a rapidly changing world. Traditionally utilized networks of field plots for inventorying forest resources require significant time and financial investments; in response to this, remote sensing techniques have been investigated for providing inventory data across large extents. These methods, including light detection and ranging (LiDAR), require significant financial investment that limits the frequency of repeated surveys. Unmanned Aerial Systems (UAS) have emerged as potential alternatives for generating fine spatial and temporal resolution 2D and 3D data for modeling forest structure. The use of Structure from Motion (SfM) photogrammetry has made it possible to use UAS to collect aerial images and generate point clouds that can be used to model vertical forest structure information in a cost-effective way. Recent research has indicated that UAS-derived SfM point clouds are comparable to LiDAR point clouds for forest structure characterization through both areabased and individual tree observations. However, substantial knowledge gaps exist regarding the influence of UAS flight parameters on SfM-derived forest attributes. This thesis presents two studies to address these knowledge gaps. Specifically, Chapter 1 investigates the influence of UAS altitude and flight speed on modeling aboveground forest biomass through an area-based approach and Chapter 2 evaluates the influence of UAS altitude, camera angle, and flight pattern on extracted tree level and summarized plot and stand level attributes. Results show a strong positive relationship between flight altitude and plot-based aboveground biomass modeling, with UAS predictions increasingly outperforming (2-24% increased variance explained) contemporary LiDAR strategies as acquisition altitude increased from 80-120 m. When monitored at the individual tree level, UAS acquisitions extremely patient throughout the entire design, planning, data collection, processing, and analysis stages of these research projects, and they would not have been possible without his extensive efforts. I would also like to thank my committee members who provided helpful guidance, assistance, and kind support throughout the course of this project: Dr. Jody Vogeler and Dr. Andrew Hudak. I would also like to thank Steven Filippelli with the Natural Resource Ecology Laboratory for his patience, time, expertise, and thoughtful insight into the inner workings of point cloud filtering and analysis, as his assistance has provided a fundamental backbone to all my photogrammetry research. v DEDICATION I would like to dedicate this thesis to my parents, Sheryl and Gregg Swayze. My parents' push towards remote sensing science from a young age has been pivotal in my development and growth as an emerging researcher in natural resource monitoring. Without their dedicated, unwavering support I would not be here today, and I will be forever grateful for their unconditional love and kindness. vi TABLE OF CONTENTS

Analysis of Forest Vegetal Characteristics of Akure Forest Reserve from Optical Imageries and Unmanned Aerial Vehicle Data

European Journal of Engineering Research and Science, 2019

Forest vegetal characteristics monitoring has a long tradition records with a success rate ranging from low to medium or high depends on the application at the hands. Details information about the indication of association of phenomena as forest indicators, such forest gap, estate and forest status, provides high spatial resolution images. The aim of this study focuses on combining unmanned Aerial Vehicles (UAVs) and satellite multispectral imaging along side by side to details forest parameter during the seasons. UAVs image at 0.15m appeared more detailed of having features such as rock, road, bare ground, riparian trees among others than that of Landsat OLI image, though the features such as rock, road, bare ground, and riparian forest were also seen on the image but it was poorly seen due to the coarse spatial resolution of 30 m. The 3-Dimensional of UAVs, relief pattern and contour from Shuttle Radar Topography Mission was also compared and this study further demonstrated on th...

Applications of unmanned aerial vehicle and 3D modelling in forestry

JOURNAL of Horticulture, Forestry and Biotechnology, 2019

The fast development of the UAV devices has led to an extended use in a variety of fields of study, both scientific and applicative. The present study will exemplify and bring arguments in favour of the use of UAV techniques in forestry (landscaping and arboriculture) through the use of a surface model (Digital Surface Model-DSM) for the USAMV Cluj Napoca university campus and a model for the identification of the dominant tree species using the spectral answer of tree crowns. The PHANTOM 3 ADVANCED drone was used for this purpose, with a HD camera which took 178 photographs during a previously defined flight, so that the degree of photography overlay was 90%. These photographs were eventually used in specialised geoinformatic software in order to create a highly precise surface model (the final resolution of the model being 2.32 cm/pixel). Taking into consideration the high degree of details, the results were used to identify the tree species which are present in the university campus by identifying their spectral characteristics, as well as to indirectly monitor the health of the trees by using a cloud of 8639052 points. The use of these modern means of forestry monitoring leads to the creation of detailed models for the analysed areas, in considerable less time and with a lower cost and use of resources in comparison to traditional methods, being suitable for different forestry activities which will be detailed in the article. Key words U.A.V., 3D modelling, forestry monitoring, drone, point cloud, mesh U.A.V. devices (Unmanned Automated Vehicle) include aerial vehicles without a pilot or flying vehicles which are remotely flown in order to obtain spatial and visual information about a territory, by remotely operating the device or in an automated mode, on a predefined flying track. The drones which are currently available on the market differ according to size, number of engines, flight autonomy, transport capacity, photo and video camera, specific teledetection and topometric sensors etc. In Romania, in order to use drones for scientific purposes, one needs to register the device at the Romanian Civil Authority for Aeronautics, and in order to fly, one needs to receive a written flight authorisation 30 days before the flight inside the built-up area and a telephonic confirmation from the same authority in the case of flights taken outside the built-up area, together with the proof of a specific flying course undertook by the drone's possessor and the existence of the drone's assurance (HG nr. 912/2010). The drones which can be found on the market have an incorporated GPS system and also highly precise digital cameras (RGB, thermal cameras, multispectral and hyperspectral cameras) which can lead to the acquisition of highly precise and accurate information in the identification of tree species (1,2). In the present study a series of general objectives have been followed: the testing of the drone in the 3D modelling of the U.S.A.M.V. campus, the execution of the flight for taking images as georeferenced raster databases, the processing of the information, generation and interpretation of results (Digital Surface Model-DSM, Mesh, Ortomozaic, Point Clouds), the identification of tree species from the U.S.A.M.V. Cluj-Napoca campus, the evaluation of the initial tree health state and last, but not least, the analysis of the applicability of U.A.V. techniques in forestry. The choice of the study area, represented by the campus of the University of Agricultural Sciences and Veterinary Medicine (U.S.A.M.V.) from Cluj Napoca, Romania, is motivated by the large diversity of tree species from this campus. This aspect has also made the research more difficult, due to the different colours present in the tree crowns, a specific habitus for each individual species and a large number of infrastructure

Sessile oak (Quercus petraea (Mattuschka) Liebl.) trees variability according to an analysis of multispectral images taken from UAV – first results

Ecological Questions, 2013

The paper presents first results of the use of multispectral aerial images to identify the outum phenophases of sessile oak. Observed phenophases are represented with three leaf colors-green, yellow and brown. Color composition of images in three spectral bands: blue, green and red, taken by digital non metric Sigma DP2 cameras, which were carried by Unmanned Aerial Vehicle (UAV) were used. Pictures were taken on 17 October 2011. Two observers made visual crowns classification of 556 oak trees into three groups: green, yellow and brown, on the basis of the dominant color of the leafs. It was found that among observers there is a large compliance in classification (79.7%). Additionally, observations of the spring growth of leafs on 54 trees crowns images recorded from seven positions were evaluated. Although the results may indicate the existence of certain trends, the clear relationship between autumn and spring phases of trees growing can not be noted now (due to small number of sample and short time of observations). The use of UAV to monitor the length of the individual tree growing season has been confirmed.

Using lightweight unmanned aerial vehicles to monitor tropical forest recovery

Biological Conservation, 2015

Large areas of tropical lands are being removed from agriculture and restored to address conservation goals. However, monitoring the ecological value of these efforts at the individual land-owner scale is rare, owing largely to issues of cost and accessibility. Traditional field-based measures for assessing forest recovery and habitat quality can be labour intensive and costly. Here we assess whether remote sensing measurements from lightweight unmanned aerial vehicles (UAV) are a cost-effective substitute for traditional field measures. An inexpensive UAV-based remote sensing methodology, ''Ecosynth'', was applied to measure forest canopy structure across field plots in a 7-9-yr tropical forest restoration study in southern Costa Rica. Ecosynth methods combine aerial images from consumer-grade digital cameras with computer vision software to generate 3D 'point cloud' models of vegetation at high spatial resolutions. Ecosynth canopy structure measurements were compared to field-based measures and their ability to predict the abundance of frugivorous birds; key seed dispersers that are sensitive to canopy structure. Ecosynth canopy height measurements were highly correlated with field-based measurements (R 2 P 0.85), a result comparable in precision to LiDAR-based remote sensing measurements. Ecosynth parameters were also strongly correlated with above-ground biomass (R 2 P 0.81) and percent canopy openness (R 2 = 0.82). Correlations were weaker with proportion-based measures such as canopy roughness (R 2 = 0.53). Several Ecosynth metrics (e.g., canopy openness and height) predicted frugivore presence and abundance at levels of accuracy similar to those of field-based measurements. Ecosynth UAV remotesensing provides an effective alternate methodology to traditional field-based measures of evaluating forest structure and complexity across landscapes. Furthermore, given the volume of data that can be generated in a single flight plan, as well as the ability to use the technology in remote areas, these methods could expand the scope of studies on forest dynamics and recovery when combined with field-based calibration plots.

AEROSPACE MONITORING OF THE FOREST ECOSYSTEM DYNAMICS WITHIN THE TERRITORY OF VRACHANSKI BALKAN NATURE PARK

In this paper the application of Remote Sensing and GIS as a means of performing aero – space monitoring of forest ecosystems dynamics is being considered. The purpose of this work is to create a model for monitoring the dynamic of forest ecosystems, based on Remote Sensing and GIS. The results of eco-monitoring can be used to update plans and policies for forest ecosystem management. The territory of Vrachanski Balkan Nature park was chosen as the subject of research as there is a certain anthropogenic pressure there. The results presented are obtained by spatial-time analysis of certain aerospace data indices. To carry out the study optical satellite images were used, on the basics of which three indices were calculated: Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI) and Normalized Difference Greenness Index (NDGI). A comparative analysis has been created and results of the degree of correlation between the different indices are presented, as well as indicators from the different test areas and related changes in the individual points in time. The results of the survey aim to assess the dynamics and condition of the forest vegetation on the territory of Vrachanski Balkan Nature park and can be utilised in activities related to monitoring, mapping and forest management.