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Unmanned Aerial Systems (UAS) are exploding as tool to image and study the environment. This collection is a small sample showing where in the world researchers are deploying these systems to better understand our dynamic world.

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latest article added on January 2015

ArticleFirst AuthorPublished
An Unmanned Aerial Vehicle for Rangeland Photography.Hardin, Perry J2005

An Unmanned Aerial Vehicle for Rangeland Photography.

Keywords

aerial photography

Abstract

Because of its perceived impracticality and expense, aerial photography from unmanned aerial vehicles (UAVs) remains virtually unused as a rangeland management tool. This underuse suggested 2 objectives. The first was to develop a UAV from off-the-shelf components that could acquire low-altitude large-scale photography for rangeland documentation. The second was to assess the UAV flight characteristics. A remotely controlled UAV suitable for 35-mm photography was built in 56 hours at a cost of $1480. In a 2-year test period, the UAV successfully completed 100+ sorties at elevations ranging from 10 m to 1000 m above ground. The average distance required for takeoff is 18.2 m whereas landing requires an average of 22.5 m. Average UAV airspeed at takeoff is about 11.4 m/s. Typical cruise speed during photograph acquisition is 13.8 m/s, resulting in 6.9 mm of blur from forward-image motion. The UAV is an inexpensive tool for monitoring rangeland condition from an aerial perspective. It is curre...

Authors

Perry J Hardin, Mark W Jackson

Year Published

2005

Publication

Rangeland Ecology & Management

Locations
DOI

10.2111/1551-5028(2005)058[0439:AUAVFR]2.0.CO;2

Comparison of Unmanned Aerial Vehicle Platforms for Assessing Vegetation Cover in Sagebrush Steppe EcosystemsBreckenridge, Robert P.2011

Comparison of Unmanned Aerial Vehicle Platforms for Assessing Vegetation Cover in Sagebrush Steppe Ecosystems

Keywords

bare ground, fixed-wing, helicopter, landscape, monitoring, remote sensing

Abstract

In this study, the use of unmanned aerial vehicles (UAVs) as a quick and safe method for monitoring biotic resources was evaluated. Vegetation cover and the amount of bare ground are important factors in understanding the sustainability of many ecosystems. Methods that improve speed and cost efficiency could greatly improve how biotic resources are monitored on western lands. Sagebrush steppe ecosystems provide important habitat for a variety of species including sage grouse and pygmy rabbit. Improved methods of monitoring these habitats are needed because not enough resource specialists or funds are available for comprehensive on-the-ground evaluations. In this project, two UAV platforms, fixed-wing and helicopter, were used to collect still-frame imagery to assess vegetation cover in sagebrush steppe ecosystems. This paper discusses the process for collecting and analyzing imagery from the UAVs to 1) estimate percentage of cover for six different vegetation types (shrub, dead shrub, grass, forb, litter, and bare ground) and 2) locate sage grouse using representative decoys. The field plots were located on the Idaho National Laboratory site west of Idaho Falls, Idaho, in areas with varying amounts and types of vegetation cover. A software program called SamplePoint was used along with visual inspection to evaluate percentage of cover for the six cover types. Results were compared against standard field measurements to assess accuracy. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform to use. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate.

Authors

Breckenridge, Robert P.; Dakins, Maxine; Bunting, Stephen; Harbour, Jerry L.; White, Sera

Year Published

2011

Publication

Rangeland Ecology & Management

Locations
DOI

10.2111/REM-D-10-00030.1

Using Unmanned Aerial Vehicles for Rangelands: Current Applications and Future PotentialsRango, Albert2006

Using Unmanned Aerial Vehicles for Rangelands: Current Applications and Future Potentials

Keywords

No keywords available

Abstract

High resolution aerial photographs have important rangeland applications, such as monitoring vegetation change, developing grazing strategies, determining rangeland health, and assessing remediation treatment effectiveness. Acquisition of high resolution images by Unmanned Aerial Vehicles (UAVs) has certain advantages over piloted aircraft missions, including lower cost, improved safety, flexibility in mission planning, and closer proximity to the target. Different levels of remote sensing data can be combined to provide more comprehensive information: 15–30 m resolution imaging from space-borne sensors for determining uniform landscape units; < 1 m satellite or aircraft data to assess the pattern of ecological states in an area of interest; 5 cm UAV images to measure gap and patch sizes as well as percent bare soil and vegetation ground cover; and < 1 cm ground-based boom photography for ground truth or reference data. Two parallel tracks of investigation are necessary: one that emphasizes the utilization of the most technically advanced sensors for research, and a second that emphasizes the minimization of costs and the maximization of simplicity for monitoring purposes. We envision that in the future, resource management agencies, rangeland consultants, and private land managers should be able to use small, lightweight UAVs to satisfy their needs for acquiring improved data at a reasonable cost, and for making appropriate management decisions.

Authors

Bestelmeyer, Brandon, Herrick, Jeffrey E., Laliberte, Andrea, Rango, Albert, Steele, Caiti, Schmugge, Thomas, Roanhorse, Abigail and Jenkins, Vince

Year Published

2006

Publication

Environmental Practice

Locations
DOI

10.1017/S1466046606060224

Texture and Scale in Object-Based Analysis of Subdecimeter Resolution Unmanned Aerial Vehicle (UAV) ImageryLaliberte, A.S.2009

Texture and Scale in Object-Based Analysis of Subdecimeter Resolution Unmanned Aerial Vehicle (UAV) Imagery

Keywords

Object-based classification, rangelands, scale, texture, unmanned aircraft.

Abstract

Imagery acquired with unmanned aerial vehicles (UAVs) has great potential for incorporation into natural resource monitoring protocols due to their ability to be deployed quickly and repeatedly and to fly at low altitudes. While the imagery may have high spatial resolution, the spectral resolution is low when lightweight off-the-shelf digital cameras are used, and the inclusion of texture measures can potentially increase the classification accuracy. Texture measures have been used widely in pixel-based image analysis, but their use in an object-based environment has not been well documented. Our objectives were to determine the most suitable texture measures and the optimal image analysis scale for differentiating rangeland vegetation using UAV imagery segmented at multiple scales. A decision tree was used to determine the optimal texture features for each segmentation scale. Results indicated the following: (1) The error rate of the decision tree was lower; (2) prediction success was higher; (3) class separability was greater; and (4) overall accuracy was higher (high 90% range) at coarser segmentation scales. The inclusion of texture measures increased classification accuracies at nearly all segmentation scales, and entropy was the texture measure with the highest score in most decision trees. The results demonstrate that UAVs are viable platforms for rangeland monitoring and that the drawbacks of low-cost off-the-shelf digital cameras can be overcome by including texture measures and using object-based image analysis which is highly suitable for very high resolution imagery.

Authors

Laliberte, A.S. and Rango, A.

Year Published

2009

Publication

IEEE Transactions on Geoscience and Remote Sensing

Locations
DOI

10.1109/TGRS.2008.2009355

An Unmanned Aerial Vehicle-Based Imaging System for 3D Measurement of Unpaved Road Surface Distresses1Zhang, Chunsun2012

An Unmanned Aerial Vehicle-Based Imaging System for 3D Measurement of Unpaved Road Surface Distresses1

Keywords

No keywords available

Abstract

Road condition data are important in transportation management systems. Over the last decades, significant progress has been made and new approaches have been proposed for efficient collection of pavement condition data. However, the assessment of unpaved road conditions has been rarely addressed in transportation research. Unpaved roads constitute approximately 40% of the U.S. road network, and are the lifeline in rural areas. Thus, it is important for timely identification and rectification of deformation on such roads. This article introduces an innovative Unmanned Aerial Vehicle (UAV)-based digital imaging system focusing on efficient collection of surface condition data over rural roads. In contrast to other approaches, aerial assessment is proposed by exploring aerial imagery acquired from an unpiloted platform to derive a three-dimensional (3D) surface model over a road distress area for distress measurement. The system consists of a low-cost model helicopter equipped with a digital camera, a Global Positioning System (GPS) receiver and an Inertial Navigation System (INS), and a geomagnetic sensor. A set of image processing algorithms has been developed for precise orientation of the acquired images, and generation of 3D road surface models and orthoimages, which allows for accurate measurement of the size and the dimension of the road surface distresses. The developed system has been tested over several test sites with roads of various surface distresses. The experiments show that the system is capable for providing 3D information of surface distresses for road condition assessment. Experiment results demonstrate that the system is very promising and provides high accuracy and reliable results. Evaluation of the system using 2D and 3D models with known dimensions shows that subcentimeter measurement accuracy is readily achieved. The comparison of the derived 3D information with the onsite manual measurements of the road distresses reveals differences of 0.50 cm, demonstrating the potential of the presented system for future practice. 2011Computer-Aided Civil and Infrastructure Engineering.

Authors

Zhang, Chunsun and Elaksher, Ahmed

Year Published

2012

Publication

Computer-Aided Civil and Infrastructure Engineering

Locations
DOI

10.1111/j.1467-8667.2011.00727.x

Unmanned Aerial Vehicle (UAV) for Monitoring Soil Erosion in Moroccod'Oleire-Oltmanns, Sebastian2012

Unmanned Aerial Vehicle (UAV) for Monitoring Soil Erosion in Morocco

Keywords

soil erosion, SFAP, photogrammetry, monitoring, UAV

Abstract

This article presents an environmental remote sensing application using a UAV that is specifically aimed at reducing the data gap between field scale and satellite scale in soil erosion monitoring in Morocco. A fixed-wing aircraft type Sirius I (MAVinci, Germany) equipped with a digital system camera (Panasonic) is employed. UAV surveys are conducted over different study sites with varying extents and flying heights in order to provide both very high resolution site-specific data and lower-resolution overviews, thus fully exploiting the large potential of the chosen UAV for multi-scale mapping purposes. Depending on the scale and area coverage, two different approaches for georeferencing are used, based on high-precision GCPs or the UAV’s log file with exterior orientation values respectively. The photogrammetric image processing enables the creation of Digital Terrain Models (DTMs) and ortho-image mosaics with very high resolution on a sub-decimetre level. The created data products were used for quantifying gully and badland erosion in 2D and 3D as well as for the analysis of the surrounding areas and landscape development for larger extents.

Authors

d'Oleire-Oltmanns, Sebastian, Marzolff, Irene, Peter, Klaus and Ries, Johannes

Year Published

2012

Publication

Remote Sensing

Locations
DOI

10.3390/rs4113390

Lightweight unmanned aerial vehicles will revolutionize spatial ecologyAnderson, Karen2013

Lightweight unmanned aerial vehicles will revolutionize spatial ecology

Keywords

No keywords available

Abstract

Ecologists require spatially explicit data to relate structure to function. To date, heavy reliance has been placed on obtaining such data from remote-sensing instruments mounted on spacecraft or manned aircraft, although the spatial and temporal resolutions of the data are often not suited to local-scale ecological investigations. Recent technological innovations have led to an upsurge in the availability of unmanned aerial vehicles (UAVs) – aircraft remotely operated from the ground – and there are now many lightweight UAVs on offer at reasonable costs. Flying low and slow, UAVs offer ecologists new opportunities for scale-appropriate measurements of ecological phenomena. Equipped with capable sensors, UAVs can deliver fine spatial resolution data at temporal resolutions defined by the end user. Recent innovations in UAV platform design have been accompanied by improvements in navigation and the miniaturization of measurement technologies, allowing the study of individual organisms and their spatiotempo...

Authors

Anderson, Karen and Gaston, Kevin J

Year Published

2013

Publication

Frontiers In Ecology And The Environment

Locations
    DOI

    10.1890/120150

    This article contributed by:

    Ecological Society of America

    Acquisition, Orthorectification, and Object-based Classification of Unmanned Aerial Vehicle (UAV) Imagery for Rangeland MonitoringLaliberte, Andrea S.2010

    Acquisition, Orthorectification, and Object-based Classification of Unmanned Aerial Vehicle (UAV) Imagery for Rangeland Monitoring

    Keywords

    No keywords available

    Abstract

    The use of unmanned aerial vehicles (UAVs) for natural resource applications has increased considerably in recent years due to their greater availability, the miniaturization of sensors, and the ability to deploy a UAV relatively quickly and repeatedly at low altitudes. We examine in this paper the potential of using a small UAV for rangeland inventory, assessment and monitoring. Imagery with a ground resolved distance of 8 cm was acquired over a 290 ha site in southwestern Idaho. We developed a semiautomated orthorectification procedure suitable for handling large numbers of small-footprint UAV images. The geometric accuracy of the orthorectified image mosaics ranged from 1.5 m to 2 m. We used object-based hierarchical image analysis to classify imagery of plots measured concurrently on the ground using standard rangeland monitoring procedures. Correlations between imageand ground-based estimates of percent cover resulted in r-squared values ranging from 0.86 to 0.98. Time estimates indicated a greater efficiency for the image-based method compared to ground measurements. The overall classification accuracies for the two image mosaics were 83 percent and 88 percent. Even under the current limitations of operating a UAV in the National Airspace, the results of this study show that UAVs can be used successfully to obtain imagery for rangeland monitoring, and that the remote sensing approach can either complement or replace some ground-based measurements. We discuss details of the UAV mission, image processing and analysis, and accuracy assessment.

    Authors

    Laliberte, Andrea S., Herrick, Jeffrey E., Rango, Albert and Winters, Craig

    Year Published

    2010

    Publication

    Photogrammetric Engineering & Remote Sensing

    Locations
    DOI

    10.14358/pers.76.6.661

    Unmanned aerial vehicle-based remote sensing for rangeland assessment, monitoring, and managementLaliberte, Andrea2009

    Unmanned aerial vehicle-based remote sensing for rangeland assessment, monitoring, and management

    Keywords

    Airborne remote sensing ; Unmanned aerial vehicles ; Data analysis ; Image processing ; Satellites

    Abstract

    Rangeland comprises as much as 70% of the Earth's land surface area. Much of this vast space is in very remote areas that are expensive and often impossible to access on the ground. Unmanned Aerial Vehicles (UAVs) have great potential for rangeland management. UAVs have several advantages over satellites and piloted aircraft: they can be deployed quickly and repeatedly; they are less costly and safer than piloted aircraft; they are flexible in terms of flying height and timing of missions; and they can obtain imagery at sub-decimeter resolution. This hyperspatial imagery allows for quantification of plant cover, composition, and structure at multiple spatial scales. Our experiments have shown that this capability, from an off-the-shelf mini-UAV, is directly applicable to operational agency needs for measuring and monitoring. For use by operational agencies to carry out their mandated responsibilities, various requirements must be met: an affordable and reliable platform; a capability for autonomous, low altitude flights; takeoff and landing in small areas surrounded by rugged terrain; and an easily applied data analysis methodology. A number of image processing and orthorectification challenges have been or are currently being addressed, but the potential to depict the land surface commensurate with field data perspectives across broader spatial extents is unrivaled.

    Authors

    Rango, Albert, Laliberte, Andrea, Herrick, Jeffrey E., Winters, Craig, Havstad, Kris, Steele, Caiti and Browning, Dawn

    Year Published

    2009

    Publication

    Journal of Applied Remote Sensing

    Locations
      DOI

      10.1117/1.3216822

      Assessing the Accuracy of Georeferenced Point Clouds Produced via Multi-View Stereopsis from Unmanned Aerial Vehicle (UAV) ImageryHarwin, Steve2012

      Assessing the Accuracy of Georeferenced Point Clouds Produced via Multi-View Stereopsis from Unmanned Aerial Vehicle (UAV) Imagery

      Keywords

      UAV; multi-view stereopsis; 3D point cloud; accuracy assessment; coastal environment

      Abstract

      Sensor miniaturisation, improved battery technology and the availability of low-cost yet advanced Unmanned Aerial Vehicles (UAV) have provided new opportunities for environmental remote sensing. The UAV provides a platform for close-range aerial photography. Detailed imagery captured from micro-UAV can produce dense point clouds using multi-view stereopsis (MVS) techniques combining photogrammetry and computer vision. This study applies MVS techniques to imagery acquired from a multi-rotor micro-UAV of a natural coastal site in southeastern Tasmania, Australia. A very dense point cloud ( < 1–3 cm point spacing) is produced in an arbitrary coordinate system using full resolution imagery, whereas other studies usually downsample the original imagery. The point cloud is sparse in areas of complex vegetation and where surfaces have a homogeneous texture. Ground control points collected with Differential Global Positioning System (DGPS) are identified and used for georeferencing via a Helmert transformation. This study compared georeferenced point clouds to a Total Station survey in order to assess and quantify their geometric accuracy. The results indicate that a georeferenced point cloud accurate to 25–40 mm can be obtained from imagery acquired from 50 m. UAV-based image capture provides the spatial and temporal resolution required to map and monitor natural landscapes. This paper assesses the accuracy of the generated point clouds based on field survey points. Based on our key findings we conclude that sub-decimetre terrain change (in this case coastal erosion) can be monitored.

      Authors

      Harwin, Steve and Lucieer, Arko

      Year Published

      2012

      Publication

      Remote Sensing

      Locations
      DOI

      10.3390/rs4061573

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