The combined use of unmanned aerial vehicles (UAVs) and structure-from-motion (SfM) is rapidly growing as a cost-effective alternative to airborne laser scanning (lidar) for reconstructing glacier surfaces. Here we present a thorough analysis of the precision and accuracy of a photogrammetric point cloud (PPC) constructed through SfM from UAV-acquired imagery over the spring snow surface at Haig Glacier, Alberta, Canada, the first of its kind in a glaciological setting. An aerial lidar survey conducted concurrently with UAV surveys was used to examine spatial patterns in the PPC accuracy. We found a median error in the PPC of −0.046 ± 0.067 m, with a 95% quantile of 0.218 m. Mean precision of the PPC was 0.199 m, with large spatially clustered outliers. We found an association between high-error, low-precision, and high-surface roughness in the PPC, likely due to illumination characteristics of the snow surface. Glacier surface reconstructions are important for geodetic mass balance measurements, giving key insights into changing climate where in situ measurements are difficult to obtain. The PPC errors are small enough that they would have minimal effects on total mass balance, should the technique be applied across the glacier.
{"title":"Evaluation of SfM for surface characterization of a snow-covered glacier through comparison with aerial lidar","authors":"E. Bash, B. Moorman, B. Menounos, Allison Gunther","doi":"10.1139/juvs-2019-0006","DOIUrl":"https://doi.org/10.1139/juvs-2019-0006","url":null,"abstract":"The combined use of unmanned aerial vehicles (UAVs) and structure-from-motion (SfM) is rapidly growing as a cost-effective alternative to airborne laser scanning (lidar) for reconstructing glacier surfaces. Here we present a thorough analysis of the precision and accuracy of a photogrammetric point cloud (PPC) constructed through SfM from UAV-acquired imagery over the spring snow surface at Haig Glacier, Alberta, Canada, the first of its kind in a glaciological setting. An aerial lidar survey conducted concurrently with UAV surveys was used to examine spatial patterns in the PPC accuracy. We found a median error in the PPC of −0.046 ± 0.067 m, with a 95% quantile of 0.218 m. Mean precision of the PPC was 0.199 m, with large spatially clustered outliers. We found an association between high-error, low-precision, and high-surface roughness in the PPC, likely due to illumination characteristics of the snow surface. Glacier surface reconstructions are important for geodetic mass balance measurements, giving key insights into changing climate where in situ measurements are difficult to obtain. The PPC errors are small enough that they would have minimal effects on total mass balance, should the technique be applied across the glacier.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43980791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. W. Albuquerque, M. Costa, M. E. Ferreira, G. Carrero, C. Grohmann
Throughout the world, restoration of degraded areas (RDA) is not only a global but also a local challenge. In this context, the Brazilian government committed itself to restore 12 million hectares of forests by 2030. RDA monitoring customarily depends on extensive fieldwork to collect data on all individuals planted. As remotely piloted aircrafts (RPAs) can reduce costs and time of fieldwork activities, studying this technology is therefore timely given. A crucial metric for RDA is the number of trees established in the area. Methods using RPAs on automatic tree counting showed good accuracy using algorithms based on the canopy height model (CHM), which is the difference between a digital surface model (DSM) and a digital terrain model (DTM). However, obtaining a DTM demands an extra computational processing step and may require field control points or manually delimiting objects on the surface. The study presented here proposes and evaluates a semi-automated methodology for counting trees directly on DSM in RDAs in the Amazon using RPA coupled with a red–green–blue standard photographic sensor. The DSM method obtained good overall accuracy and F-score indexes, superior to the CHM method for all study areas even when overall accuracy was low for both methods.
{"title":"Remotely piloted aircraft imagery for automatic tree counting in forest restoration areas: a case study in the Amazon","authors":"R. W. Albuquerque, M. Costa, M. E. Ferreira, G. Carrero, C. Grohmann","doi":"10.1139/juvs-2019-0024","DOIUrl":"https://doi.org/10.1139/juvs-2019-0024","url":null,"abstract":"Throughout the world, restoration of degraded areas (RDA) is not only a global but also a local challenge. In this context, the Brazilian government committed itself to restore 12 million hectares of forests by 2030. RDA monitoring customarily depends on extensive fieldwork to collect data on all individuals planted. As remotely piloted aircrafts (RPAs) can reduce costs and time of fieldwork activities, studying this technology is therefore timely given. A crucial metric for RDA is the number of trees established in the area. Methods using RPAs on automatic tree counting showed good accuracy using algorithms based on the canopy height model (CHM), which is the difference between a digital surface model (DSM) and a digital terrain model (DTM). However, obtaining a DTM demands an extra computational processing step and may require field control points or manually delimiting objects on the surface. The study presented here proposes and evaluates a semi-automated methodology for counting trees directly on DSM in RDAs in the Amazon using RPA coupled with a red–green–blue standard photographic sensor. The DSM method obtained good overall accuracy and F-score indexes, superior to the CHM method for all study areas even when overall accuracy was low for both methods.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49342648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There is increasing demand to operate unmanned aircraft systems (UAS) in congested terminal environments, such as busy commercial airports. With this demand comes challenges to pilots. To identify these challenges, we conducted critical decision method (CDM) interviews with pilots. CDM is a cognitive task analysis method aimed at uncovering tacit cognitive challenges. Eight pilots from the U.S. were interviewed including four UAS pilots and four commercial pilots. Interviews were analyzed using thematic analysis, resulting in the identification of four categories of cognitive challenges: (i) noticing anomalies, (ii) diagnosing automation behavior, (iii) understanding when and how to intervene, and (iv) coordinating with air traffic control. In this paper, we describe each challenge, highlight real-world examples from our interviews, and provide some recommendations for addressing the implications of integrating UAS in congested terminal airspace.
{"title":"UAS integration in congested terminal airspace: challenges posed to pilots","authors":"Julie Diiulio, L. Militello, Devorah E. Klein","doi":"10.1139/juvs-2019-0015","DOIUrl":"https://doi.org/10.1139/juvs-2019-0015","url":null,"abstract":"There is increasing demand to operate unmanned aircraft systems (UAS) in congested terminal environments, such as busy commercial airports. With this demand comes challenges to pilots. To identify these challenges, we conducted critical decision method (CDM) interviews with pilots. CDM is a cognitive task analysis method aimed at uncovering tacit cognitive challenges. Eight pilots from the U.S. were interviewed including four UAS pilots and four commercial pilots. Interviews were analyzed using thematic analysis, resulting in the identification of four categories of cognitive challenges: (i) noticing anomalies, (ii) diagnosing automation behavior, (iii) understanding when and how to intervene, and (iv) coordinating with air traffic control. In this paper, we describe each challenge, highlight real-world examples from our interviews, and provide some recommendations for addressing the implications of integrating UAS in congested terminal airspace.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42799794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Jech, Jennifer J. Johnson, M. Lutcavage, Angelia S. M. Vanderlaan, Y. Rzhanov, D. LeRoi
An APH-22 vertical-takeoff-and-landing hexacopter was used to collect aerial images of schools and individuals of juvenile Atlantic bluefin tuna (ABFT; Thunnus thynnus) at the sea surface in the southern Gulf of Maine. Quantitative measures of fish length, width, and inter-fish spacing were obtained from these images by applying calibration settings and performance measures from calibrating, testing, and evaluating the onboard motion and altimeter sensors and the digital camera and lenses. The accuracy and precision of the onboard motion sensors, camera, and lens calibrations were sufficient to provide length measurements to sub-centimeter precision, but the altimeter performance was least reliable and required additional information, such as images of known-sized objects during each flight, to provide measurements at the accuracy and precision needed for data to be incorporated in fisheries management. The APH-22 was ideal for acquiring images of ABFT individuals and schools and may be a useful tool for remotely monitoring the behavior and body condition of these elusive animals.
{"title":"Measurements of juvenile Atlantic bluefin tuna (Thunnus thynnus) size using an unmanned aerial system","authors":"J. Jech, Jennifer J. Johnson, M. Lutcavage, Angelia S. M. Vanderlaan, Y. Rzhanov, D. LeRoi","doi":"10.1139/juvs-2018-0039","DOIUrl":"https://doi.org/10.1139/juvs-2018-0039","url":null,"abstract":"An APH-22 vertical-takeoff-and-landing hexacopter was used to collect aerial images of schools and individuals of juvenile Atlantic bluefin tuna (ABFT; Thunnus thynnus) at the sea surface in the southern Gulf of Maine. Quantitative measures of fish length, width, and inter-fish spacing were obtained from these images by applying calibration settings and performance measures from calibrating, testing, and evaluating the onboard motion and altimeter sensors and the digital camera and lenses. The accuracy and precision of the onboard motion sensors, camera, and lens calibrations were sufficient to provide length measurements to sub-centimeter precision, but the altimeter performance was least reliable and required additional information, such as images of known-sized objects during each flight, to provide measurements at the accuracy and precision needed for data to be incorporated in fisheries management. The APH-22 was ideal for acquiring images of ABFT individuals and schools and may be a useful tool for remotely monitoring the behavior and body condition of these elusive animals.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2018-0039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44492778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Unmanned aircraft systems (UAS) can be safer, less expensive, and less labor intensive than manned aircraft in wildlife conservation programs. Consequently, the use of UAS is increasing, but other than installation of line markers to reduce avian collision with power lines, UAS approaches generally involve passive observations. We wondered if UAS could more actively help guide conservation decision-making, so we used UAS-sourced photographs to create 3D models of cliffs to conduct viewshed-based assessments of potential disturbance to nesting raptors by recreational rock climbing. At Cathedral Spires Park and Clear Creek Canyon Park in Jefferson County, Colo., we collected 4790 photographs from which we constructed 3D models. We identified climbing routes and climbing areas with potential to disturb nesting Peregrine Falcons (Falco peregrinus) and Golden Eagles (Aquila chrysaetos). Our findings were useful in providing Jefferson County Open Space (JCOS) with quantitative data so that informed defensible resource management decisions could be made. This project provides an example of how UAS can be used to actively create products useful in wildlife conservation and management and, given the widespread and increasing popularity of rock climbing globally, likely can be generalized to other areas worldwide where rock climbers and nesting raptors share cliffs.
{"title":"Unmanned aircraft systems enable three-dimensional viewshed-based assessment of potential disturbance to nesting raptors by recreational rock climbing","authors":"J. F. Dwyer, Daryl D. Austin, Chelsea K. Beebe","doi":"10.1139/juvs-2019-0014","DOIUrl":"https://doi.org/10.1139/juvs-2019-0014","url":null,"abstract":"Unmanned aircraft systems (UAS) can be safer, less expensive, and less labor intensive than manned aircraft in wildlife conservation programs. Consequently, the use of UAS is increasing, but other than installation of line markers to reduce avian collision with power lines, UAS approaches generally involve passive observations. We wondered if UAS could more actively help guide conservation decision-making, so we used UAS-sourced photographs to create 3D models of cliffs to conduct viewshed-based assessments of potential disturbance to nesting raptors by recreational rock climbing. At Cathedral Spires Park and Clear Creek Canyon Park in Jefferson County, Colo., we collected 4790 photographs from which we constructed 3D models. We identified climbing routes and climbing areas with potential to disturb nesting Peregrine Falcons (Falco peregrinus) and Golden Eagles (Aquila chrysaetos). Our findings were useful in providing Jefferson County Open Space (JCOS) with quantitative data so that informed defensible resource management decisions could be made. This project provides an example of how UAS can be used to actively create products useful in wildlife conservation and management and, given the widespread and increasing popularity of rock climbing globally, likely can be generalized to other areas worldwide where rock climbers and nesting raptors share cliffs.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46380824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proper redistribution of residual slash following harvesting is crucial for ensuring successful regeneration and continued health in trembling aspen (Populus tremuloides) forests. As traditional methods of measuring residual slash are a strenuous and tedious process, the objective of this study was to develop a new, faster, and more detailed method to assess residual slash distribution for entire harvested blocks. This study also aimed to assess the influence residual slash coverage had on the success of aspen regeneration 1 year after winter harvesting. Using high-resolution UAV imagery and maximum likelihood supervised image classification, residual slash was differentiated from the underlying forest floor. Overall, classification accuracy ranged between 85% and 96% with the highest accuracy occurring when aerial imagery was collected at the beginning of the second spring following winter harvesting. Slash distribution was quite consistent across harvested blocks, with 92% of harvested blocks experiencing <33% coverage. There was no relationship between the level of aspen regeneration following 1 year of growth and percentage slash coverage up to 60%. No vegetation plots occurred in areas with >60% slash coverage; therefore, it is unknown whether aspen regeneration will be affected in areas with higher slash coverage.
{"title":"Assessment of residual slash coverage using UAVs and implications for aspen regeneration","authors":"L. Sealey, K. Rees","doi":"10.1139/juvs-2019-0001","DOIUrl":"https://doi.org/10.1139/juvs-2019-0001","url":null,"abstract":"Proper redistribution of residual slash following harvesting is crucial for ensuring successful regeneration and continued health in trembling aspen (Populus tremuloides) forests. As traditional methods of measuring residual slash are a strenuous and tedious process, the objective of this study was to develop a new, faster, and more detailed method to assess residual slash distribution for entire harvested blocks. This study also aimed to assess the influence residual slash coverage had on the success of aspen regeneration 1 year after winter harvesting. Using high-resolution UAV imagery and maximum likelihood supervised image classification, residual slash was differentiated from the underlying forest floor. Overall, classification accuracy ranged between 85% and 96% with the highest accuracy occurring when aerial imagery was collected at the beginning of the second spring following winter harvesting. Slash distribution was quite consistent across harvested blocks, with 92% of harvested blocks experiencing <33% coverage. There was no relationship between the level of aspen regeneration following 1 year of growth and percentage slash coverage up to 60%. No vegetation plots occurred in areas with >60% slash coverage; therefore, it is unknown whether aspen regeneration will be affected in areas with higher slash coverage.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48498454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes a parametric study on the design of the structural wing members of a weight-shift aircraft for the conversion from piloted to unmanned cargo delivery operations. Ultralight weight-shift aircraft wings are designed for both pilot control and structural stability. These wings have evolved over decades without much formal engineering, and there is little scientific literature describing their design. Since modifications to the structural members of the wing are required to replace the pilot with an enclosed cargo bay, a parametric study on the wing design was conducted. The loads on each member of the wing were modelled, and nonlinear buckling simulations were performed to determine the minimum structural member tube sizes.
{"title":"On the design of structural wing members for an unmanned weight-shift aircraft","authors":"E. Lanteigne, J. McLeod, M. Vadsola, Shilong Liu","doi":"10.1139/juvs-2019-0012","DOIUrl":"https://doi.org/10.1139/juvs-2019-0012","url":null,"abstract":"This paper describes a parametric study on the design of the structural wing members of a weight-shift aircraft for the conversion from piloted to unmanned cargo delivery operations. Ultralight weight-shift aircraft wings are designed for both pilot control and structural stability. These wings have evolved over decades without much formal engineering, and there is little scientific literature describing their design. Since modifications to the structural members of the wing are required to replace the pilot with an enclosed cargo bay, a parametric study on the wing design was conducted. The loads on each member of the wing were modelled, and nonlinear buckling simulations were performed to determine the minimum structural member tube sizes.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2020-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46553265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of unmanned aerial vehicles, or drones, in wildlife monitoring has increased in recent years, particularly in hard-to-access habitats. We used fixed-wing and quadcopter drones to census an urban-nesting population of Glaucous-winged Gulls in Victoria, Canada. We conducted our study over 2 years and asked whether (i) drones represent a suitable survey method for rooftop-nesting gulls in our study region; and (ii) Victoria’s urban gull population had increased since the last survey >30 years earlier. Using orthomosaic imagery derived from drone overflights, we estimated at least a threefold increase over the 1986 count reported for the entire city (from 114 to 346 pairs), and an approximate tenfold increase in the number of gulls nesting in the downtown core. Drones proved to be an excellent platform from which to census rooftop-nesting birds: occupied nests were readily discernible in our digital imagery, and incubating birds were undisturbed by drones. This lack of disturbance may be due to Victoria’s location in an aerodrome; gulls experience dozens of floatplane and helicopter flights per day and are likely habituated to air traffic. Glaucous-winged Gulls have declined considerably at their natural island colonies in the region since the 1980s. Our results indicate that although urban roofs provide replacement nesting habitat for this species, local gull populations have not simply relocated en masse from islands to rooftops in the region.
{"title":"Evaluating UAV-based techniques to census an urban-nesting gull population on Canada’s Pacific coast","authors":"L. Blight, D. Bertram, Edward Kroc","doi":"10.1139/juvs-2019-0005","DOIUrl":"https://doi.org/10.1139/juvs-2019-0005","url":null,"abstract":"The use of unmanned aerial vehicles, or drones, in wildlife monitoring has increased in recent years, particularly in hard-to-access habitats. We used fixed-wing and quadcopter drones to census an urban-nesting population of Glaucous-winged Gulls in Victoria, Canada. We conducted our study over 2 years and asked whether (i) drones represent a suitable survey method for rooftop-nesting gulls in our study region; and (ii) Victoria’s urban gull population had increased since the last survey >30 years earlier. Using orthomosaic imagery derived from drone overflights, we estimated at least a threefold increase over the 1986 count reported for the entire city (from 114 to 346 pairs), and an approximate tenfold increase in the number of gulls nesting in the downtown core. Drones proved to be an excellent platform from which to census rooftop-nesting birds: occupied nests were readily discernible in our digital imagery, and incubating birds were undisturbed by drones. This lack of disturbance may be due to Victoria’s location in an aerodrome; gulls experience dozens of floatplane and helicopter flights per day and are likely habituated to air traffic. Glaucous-winged Gulls have declined considerably at their natural island colonies in the region since the 1980s. Our results indicate that although urban roofs provide replacement nesting habitat for this species, local gull populations have not simply relocated en masse from islands to rooftops in the region.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2019-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/juvs-2019-0005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43214789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Unmanned aerial vehicle images are considered an important tool in close-range photogrammetry for topographic map production and 3D modelling using structure-from-motion approaches. The effect of overlap percentage in vertical and integrated vertical and oblique images on accuracy is evaluated. Analysis showed that the accuracy of the photogrammetric products (e.g., digital surface model and orthoimagery) is increased with the increased overlap percentage in vertical images. The accuracy is better when oblique images are integrated into vertical images than when only vertical images are used even with the same number of images. Furthermore, the building façade is constructed, but the building suffers from noise. Increasing the number of integrated vertical and oblique images improves the accuracy of the products and provides considerable precision to 3D modelling. This study showed that the improved result is due to the increased redundancy in image matching and optimised parameters of interior orientation through self-calibration. The images are processed using Pix4D software.
{"title":"Accuracy assessment using different UAV image overlaps","authors":"H. Sadeq","doi":"10.1139/JUVS-2018-0014","DOIUrl":"https://doi.org/10.1139/JUVS-2018-0014","url":null,"abstract":"Unmanned aerial vehicle images are considered an important tool in close-range photogrammetry for topographic map production and 3D modelling using structure-from-motion approaches. The effect of overlap percentage in vertical and integrated vertical and oblique images on accuracy is evaluated. Analysis showed that the accuracy of the photogrammetric products (e.g., digital surface model and orthoimagery) is increased with the increased overlap percentage in vertical images. The accuracy is better when oblique images are integrated into vertical images than when only vertical images are used even with the same number of images. Furthermore, the building façade is constructed, but the building suffers from noise. Increasing the number of integrated vertical and oblique images improves the accuracy of the products and provides considerable precision to 3D modelling. This study showed that the improved result is due to the increased redundancy in image matching and optimised parameters of interior orientation through self-calibration. The images are processed using Pix4D software.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2019-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/JUVS-2018-0014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42858256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Janell C. Walther, L. PytlikZillig, Carrick Detweiler, A. Houston
Unmanned aerial systems (UAS) can advance understanding of the atmosphere and improve weather prediction, but public perceptions of drone technologies need to be assessed to ensure successful societal integration. Our qualitative study examines public perceptions of UAS technology, and the associated risks and benefits, for such civilian purposes. We examine how people form perceptions, and discuss the implications of these perceptions for UAS design and regulation. Our study finds the public to be favorable toward UAS used for “noble” purposes. Participant views are informed by popular media, personal experiences, comparisons between technologies, and consideration of the trustworthiness of the users, regulators, and technology itself.
{"title":"How people make sense of drones used for atmospheric science (and other purposes): hopes, concerns, and recommendations","authors":"Janell C. Walther, L. PytlikZillig, Carrick Detweiler, A. Houston","doi":"10.1139/JUVS-2019-0003","DOIUrl":"https://doi.org/10.1139/JUVS-2019-0003","url":null,"abstract":"Unmanned aerial systems (UAS) can advance understanding of the atmosphere and improve weather prediction, but public perceptions of drone technologies need to be assessed to ensure successful societal integration. Our qualitative study examines public perceptions of UAS technology, and the associated risks and benefits, for such civilian purposes. We examine how people form perceptions, and discuss the implications of these perceptions for UAS design and regulation. Our study finds the public to be favorable toward UAS used for “noble” purposes. Participant views are informed by popular media, personal experiences, comparisons between technologies, and consideration of the trustworthiness of the users, regulators, and technology itself.","PeriodicalId":45619,"journal":{"name":"Journal of Unmanned Vehicle Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2019-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/JUVS-2019-0003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44624556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：