Hubert T. Samboko, S. Schurer, H. Savenije, H. Makurira, K. Banda, H. Winsemius
{"title":"评估用于运输计算的低成本地形测量","authors":"Hubert T. Samboko, S. Schurer, H. Savenije, H. Makurira, K. Banda, H. Winsemius","doi":"10.5194/gi-11-1-2022","DOIUrl":null,"url":null,"abstract":"Abstract. Rapid modern technological advancements have led to\nsignificant improvements in river monitoring using unmanned aerial vehicles\n(UAVs), photogrammetric reconstruction software, and low-cost real-time\nkinematic Global Navigation Satellite System (RTK GNSS) equipment. UAVs\nallow for the collection of dry bathymetric data in environments that are\ndifficult to access. Low-cost RTK GNSS equipment facilitates accurate\nmeasurement of wet bathymetry when combined with subaqueous measuring tools\nsuch as acoustic Doppler current profilers (ADCPs). Hydraulic models may be\nconstructed from these data, which in turn can be used for various\napplications such as water management, forecasting, early warning and\ndisaster preparedness by responsible water authorities, and construction of\nriver rating curves. We hypothesise that the reconstruction of dry terrain\nwith UAV-based photogrammetry combined with RTK GNSS equipment leads\nto accurate geometries particularly fit for hydraulic understanding and\nsimulation models. This study sought to (1) compare open-source and\ncommercial photogrammetry packages to verify if water authorities with low\nresource availability have the option to utilise open-source packages\nwithout significant compromise on accuracy; (2) assess the impact of\nvariations in the number of ground control points (GCPs) and the\ndistribution of the GCP markers on the quality of digital elevation models\n(DEMs), with a particular emphasis on characteristics that impact\nhydraulics; and (3) investigate the impact of using reconstructions based\non different GCP numbers on conveyance and hydraulic slope. A novel method\nwhich makes use of a simple RTK tie line along the water edge measured using\na low-cost but highly accurate GNSS is presented so as to correct the\nunwanted effect of lens distortion (“doming effect”) and enable the\nconcatenation of geometric data from different sources. Furthermore, we\ndescribe how merging of the dry and wet bathymetry can be achieved through\ngridding based on linear interpolation. We tested our approach over a\nsection of the Luangwa River in Zambia. Results indicate that the\nopen-source software photogrammetry package is capable of producing results\nthat are comparable to commercially available options. We determined that\nGCPs are essential for vertical accuracy, but also that an increase in the\nnumber of GCPs above a limited number of five only moderately increases the\naccuracy of results, provided the GCPs are well spaced in both the horizontal\nand vertical dimension. Furthermore, insignificant differences in hydraulic\ngeometries among the various cross sections are observed, corroborating the\nfact that a limited well-spaced set of GCPs is enough to establish a\nhydraulically sound reconstruction. However, it appeared necessary to make\nan additional observation of the hydraulic slope. A slope derived merely\nfrom the UAV survey was shown to be prone to considerable errors caused by\nlens distortion. Combination of the photogrammetry results with the RTK GNSS\ntie line was shown to be essential to correct the slope and made the\nreconstruction suitable for hydraulic model setup.\n","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":"{\"title\":\"Evaluating low-cost topographic surveys for computations of conveyance\",\"authors\":\"Hubert T. Samboko, S. Schurer, H. Savenije, H. Makurira, K. Banda, H. Winsemius\",\"doi\":\"10.5194/gi-11-1-2022\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Rapid modern technological advancements have led to\\nsignificant improvements in river monitoring using unmanned aerial vehicles\\n(UAVs), photogrammetric reconstruction software, and low-cost real-time\\nkinematic Global Navigation Satellite System (RTK GNSS) equipment. UAVs\\nallow for the collection of dry bathymetric data in environments that are\\ndifficult to access. Low-cost RTK GNSS equipment facilitates accurate\\nmeasurement of wet bathymetry when combined with subaqueous measuring tools\\nsuch as acoustic Doppler current profilers (ADCPs). Hydraulic models may be\\nconstructed from these data, which in turn can be used for various\\napplications such as water management, forecasting, early warning and\\ndisaster preparedness by responsible water authorities, and construction of\\nriver rating curves. We hypothesise that the reconstruction of dry terrain\\nwith UAV-based photogrammetry combined with RTK GNSS equipment leads\\nto accurate geometries particularly fit for hydraulic understanding and\\nsimulation models. This study sought to (1) compare open-source and\\ncommercial photogrammetry packages to verify if water authorities with low\\nresource availability have the option to utilise open-source packages\\nwithout significant compromise on accuracy; (2) assess the impact of\\nvariations in the number of ground control points (GCPs) and the\\ndistribution of the GCP markers on the quality of digital elevation models\\n(DEMs), with a particular emphasis on characteristics that impact\\nhydraulics; and (3) investigate the impact of using reconstructions based\\non different GCP numbers on conveyance and hydraulic slope. A novel method\\nwhich makes use of a simple RTK tie line along the water edge measured using\\na low-cost but highly accurate GNSS is presented so as to correct the\\nunwanted effect of lens distortion (“doming effect”) and enable the\\nconcatenation of geometric data from different sources. Furthermore, we\\ndescribe how merging of the dry and wet bathymetry can be achieved through\\ngridding based on linear interpolation. We tested our approach over a\\nsection of the Luangwa River in Zambia. Results indicate that the\\nopen-source software photogrammetry package is capable of producing results\\nthat are comparable to commercially available options. We determined that\\nGCPs are essential for vertical accuracy, but also that an increase in the\\nnumber of GCPs above a limited number of five only moderately increases the\\naccuracy of results, provided the GCPs are well spaced in both the horizontal\\nand vertical dimension. Furthermore, insignificant differences in hydraulic\\ngeometries among the various cross sections are observed, corroborating the\\nfact that a limited well-spaced set of GCPs is enough to establish a\\nhydraulically sound reconstruction. However, it appeared necessary to make\\nan additional observation of the hydraulic slope. A slope derived merely\\nfrom the UAV survey was shown to be prone to considerable errors caused by\\nlens distortion. Combination of the photogrammetry results with the RTK GNSS\\ntie line was shown to be essential to correct the slope and made the\\nreconstruction suitable for hydraulic model setup.\\n\",\"PeriodicalId\":48742,\"journal\":{\"name\":\"Geoscientific Instrumentation Methods and Data Systems\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.8000,\"publicationDate\":\"2022-01-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"5\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Geoscientific Instrumentation Methods and Data Systems\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.5194/gi-11-1-2022\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geoscientific Instrumentation Methods and Data Systems","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/gi-11-1-2022","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Evaluating low-cost topographic surveys for computations of conveyance
Abstract. Rapid modern technological advancements have led to
significant improvements in river monitoring using unmanned aerial vehicles
(UAVs), photogrammetric reconstruction software, and low-cost real-time
kinematic Global Navigation Satellite System (RTK GNSS) equipment. UAVs
allow for the collection of dry bathymetric data in environments that are
difficult to access. Low-cost RTK GNSS equipment facilitates accurate
measurement of wet bathymetry when combined with subaqueous measuring tools
such as acoustic Doppler current profilers (ADCPs). Hydraulic models may be
constructed from these data, which in turn can be used for various
applications such as water management, forecasting, early warning and
disaster preparedness by responsible water authorities, and construction of
river rating curves. We hypothesise that the reconstruction of dry terrain
with UAV-based photogrammetry combined with RTK GNSS equipment leads
to accurate geometries particularly fit for hydraulic understanding and
simulation models. This study sought to (1) compare open-source and
commercial photogrammetry packages to verify if water authorities with low
resource availability have the option to utilise open-source packages
without significant compromise on accuracy; (2) assess the impact of
variations in the number of ground control points (GCPs) and the
distribution of the GCP markers on the quality of digital elevation models
(DEMs), with a particular emphasis on characteristics that impact
hydraulics; and (3) investigate the impact of using reconstructions based
on different GCP numbers on conveyance and hydraulic slope. A novel method
which makes use of a simple RTK tie line along the water edge measured using
a low-cost but highly accurate GNSS is presented so as to correct the
unwanted effect of lens distortion (“doming effect”) and enable the
concatenation of geometric data from different sources. Furthermore, we
describe how merging of the dry and wet bathymetry can be achieved through
gridding based on linear interpolation. We tested our approach over a
section of the Luangwa River in Zambia. Results indicate that the
open-source software photogrammetry package is capable of producing results
that are comparable to commercially available options. We determined that
GCPs are essential for vertical accuracy, but also that an increase in the
number of GCPs above a limited number of five only moderately increases the
accuracy of results, provided the GCPs are well spaced in both the horizontal
and vertical dimension. Furthermore, insignificant differences in hydraulic
geometries among the various cross sections are observed, corroborating the
fact that a limited well-spaced set of GCPs is enough to establish a
hydraulically sound reconstruction. However, it appeared necessary to make
an additional observation of the hydraulic slope. A slope derived merely
from the UAV survey was shown to be prone to considerable errors caused by
lens distortion. Combination of the photogrammetry results with the RTK GNSS
tie line was shown to be essential to correct the slope and made the
reconstruction suitable for hydraulic model setup.
期刊介绍:
Geoscientific Instrumentation, Methods and Data Systems (GI) is an open-access interdisciplinary electronic journal for swift publication of original articles and short communications in the area of geoscientific instruments. It covers three main areas: (i) atmospheric and geospace sciences, (ii) earth science, and (iii) ocean science. A unique feature of the journal is the emphasis on synergy between science and technology that facilitates advances in GI. These advances include but are not limited to the following:
concepts, design, and description of instrumentation and data systems;
retrieval techniques of scientific products from measurements;
calibration and data quality assessment;
uncertainty in measurements;
newly developed and planned research platforms and community instrumentation capabilities;
major national and international field campaigns and observational research programs;
new observational strategies to address societal needs in areas such as monitoring climate change and preventing natural disasters;
networking of instruments for enhancing high temporal and spatial resolution of observations.
GI has an innovative two-stage publication process involving the scientific discussion forum Geoscientific Instrumentation, Methods and Data Systems Discussions (GID), which has been designed to do the following:
foster scientific discussion;
maximize the effectiveness and transparency of scientific quality assurance;
enable rapid publication;
make scientific publications freely accessible.