Geospatial Data Acquisition Research Articles

Open-Source Solutions for Real-Time 3D Geospatial Web Integration

Abstract. The recent development of Urban Digital Twin (UDT) structures and the spread of Internet of Things (IoT) technology have extended the concept of Digital Twin (DT) to urban environment representation, enabling real-time connections between geospatial representations and their real-world counterparts. Concurrently, advancements in surveying technologies and web geospatial services have facilitated the acquisition of extensive 2D and 3D geospatial data, making their spatial integration essential. While some proprietary software solutions have recently enabled initial examples of UDT by integrating various 3D geospatial data and real-time sensor acquisition, the development of open-source solutions for real-time web-based geospatial management remains a challenge. This work demonstrates a possible open-source solution for developing a UDT accessible via the web. The case study involves the web visualization platform of the new Faculty of ITC building at the University of Twente in Enschede (The Netherlands), which is connected in real-time with weather data services provided by Visual Crossing (1). The platform is based on an HTML5 framework and employs WebGL JavaScript graphic libraries to visualize different modules of 3D web visualization that integrate various local and remote 3D datasets. The framework adopted in this experiment can be used in the future for developing low-cost UDT web platforms beneficial for researchers, municipalities, and private companies interested in the real-time geospatial management of urban environments.

Preparation of a Map of Potential Areas For the Installation of a Sewage Treatment Plant in the Porto Murtinho/MS Region

Objective: The main objective is to prepare a thematic map to identify potential areas for the installation of a Sewage Treatment Station (ETE). Theoretical Framework: This study addresses the importance of selecting locations for the installation of ETEs, which prioritize environmental and social aspects, in which geotechnologies are presented as valuable tools for efficient and integrated analysis. Method: The methodology of this research was based on the acquisition and processing of geospatial and environmental data, complemented by the generation of thematic maps such as watercourses, areas subject to flooding, roads, land use and occupation, slope, soils and distances from the urban perimeter. Data integration through map algebra was performed in the QGIS software, in addition, WRPLOT View was used for the directional analysis of the winds in Porto Murtinho/MS. Results and Discussion: The results of this study indicate that the areas with the greatest potential for installation are mostly located within 1 (one) kilometer of the urban perimeter security strip. The analysis of the prevailing winds revealed that they form a corridor in the north/south direction, suggesting that the regions east of the city are more suitable for the implementation of the treatment system. Research Implications: The multifaceted approach, considering environmental and operational factors, makes it possible to identify suitable areas for ETEs. Originality/Value: This study was developed, highlighting that limiting factors are essential in identifying areas unsuitable for installing the structure, while non-limiting maps are essential for classifying the installation potential.

EVALUATING THE QUALITY OF DIGITAL DATASETS IN TERMS OF AVIATION SAFETY DERIVED FROM STEREO SATELLITE IMAGERY IN SARAWAK, MALAYSIA'S AIRPORTS

Abstract. High-resolution satellite imagery offers new possibilities in geospatial data acquisition, particularly in 3D city modeling, topographic mapping, and aviation safety. This study evaluates the quality of digital datasets generated from satellite imagery for five airports in Sarawak, as part of the eTOD (Electronic Terrain and Obstacle Data) project conducted by the Civil Aviation Authority of Malaysia (CAAM). The airports under examination include Miri Airport (WBGR), Bintulu Airport (WBGB), Mukah Airport (WBGK), Sibu Airport (WBGS), and Kuching Airport (WBGG). A comprehensive assessment was conducted to evaluate accuracy and reliability by combining stereo satellite imagery with on-site validation. The study yielded digital datasets of exceptionally high accuracy and reliability. The overall error rate remained below 3%, with a mean error value of 0.96 meters across all five airports. Notably, it has been observed that using satellite images as the only data source creates difficulties in detecting Power Transmission Lines and Poles that require precise detection. A multifaceted approach was adopted to increase the detection accuracy, involving site verification measurements, incorporation of external source data (Sarawak Energy Company), and manual interpretation. In conclusion, this study underscores the significant potential of very high-resolution satellite imagery for creating precise and reliable digital datasets for aviation safety. Additionally, the study's emphasis on detecting Power Transmission Lines highlights the need for advanced methods to improve accuracy in challenging scenarios. These findings not only contribute to enhancing aviation safety but also provide valuable insights into the utilization of satellite imagery for similar applications worldwide.

Geomatic tools used in the management of agricultural activities: a systematic review

AbstractManaging agricultural activity encompasses technology, geographic information, spatial data and geomatic tools as support techniques. In this framework, agricultural mapping is an essential geomatic application due to its importance in managing food systems. This research aims to analyze the state of knowledge of geomatics tools and their applications in agriculture through a systematic review of scientific documents and methodological approaches, highlighting the use of geomatics in agricultural mapping to evaluate trends in agriculture management. The study methodology consists of a scientific base of publications on geomatics and its applications in sustainable agriculture, with a quantitative analysis of production and its approaches. Subsequently, PRISMA establishes a systematic review in search of the subject’s methods, applications and trends. The results show that of the total data analyzed, 60% corresponds to general agricultural mapping for crop/water/soil mapping using satellite images. Twenty percent for land use and coverage, considering the georeferencing that contributes to agricultural territorial planning. Nine percent consider geomatic key for agricultural cadastre (plot management). In addition, 6% corresponds to precision agriculture and 5% to watershed management. The most predominant geomatics tools are: Geographic Information System (GIS), Global Positioning System (GPS), unmanned aerial vehicle (UAV) and remote sensing (RS). Also, among the most used geomatic techniques in agricultural cartography, photogrammetry in crop phenology and multispectral analysis in the optimisation and monitoring of agricultural production stand out. Studies show that the geomatic application promotes sustainability practices such as crop rotation, seeds dispersed and germinated by animals, agricultural irrigation through rivers/basins/streams, family gardens and generation of employment sources. The geomatics use is of great utility/potential for the acquisition and generation of geospatial data accurately, with time and cost savings that contribute to the decision-making of city councils, public cadastral administrations, enterprises, educational institutions and agricultural foundations.

APPLICATION OF NATURAL LANGUAGE PARSING FOR IDENTIFYING NON-SURVEYED BOUNDARIES TOWARDS ENHANCED SYSTEMATIC LAND TITLING: RESULTS FROM PRELIMINARY EXPERIMENT

The need for the adoption of systematic land titling (SLT) in Nigeria cannot be overemphasised. Nonetheless, the problems of speed and cost of geospatial data acquisition, as well as identification of non-surveyed boundaries, remain unresolved, impeding the effectiveness of SLT for non-surveyed boundaries. The integration of language into Artificial Intelligence (AI) has allowed Natural Language Parsing (NLP) to effectively serve as a tool for communication between humans and computer systems. This study presents preliminary results of testing a prototype application that utilises NLP to convert textual descriptions into graphic sketches as a tool towards the production of a-priori sketches that can aid SLT in non-surveyed boundaries. The study determines that NLP alone cannot be used to achieve the required accuracy in geospatial data for SLT; however, the study concludes that NLP can be integrated alongside other ancillary information to enhance SLT in peri-urban regions.

INVESTIGATIONS ON INSAR DATA PROCESSING STANDARD FOR VOLCANO ISLAND MONITORING IN INDONESIA

Abstract. In critical situations such as disaster and humanitarian relief, the reliable geospatial data will present an appropriate decision on a timely manner. As fundamental datasets, large-scale topographic maps are are mandatory in order to perform geospatial analysis for many societal challenges. Indeed, Large Scale Topographic Mapping in Indonesia shall be accelerated in an innovative and productive way to consider the production efficiency, especially for the geospatial data acquisition as its primary source. Interferometric Synthetic Aperture Radar (InSAR) data acquisition presents some advantages, especially in conjunction with the security clearance and global weather as some main constraints for the geospatial data acquisition. In terms of disaster preparedness and emergency response, radar interferometry techniques can play an important role by generating a Digital Elevation Model (DEM) as an input to Decision Support Systems (DSS). In addition, the techniques of differential Interferometric Synthetic Aperture Radar (D-InSAR) can provide the earth surface deformation from time series Radar Datasets. A set of standards related to the InSAR data acquisition are essential, especially with regards to the improved sensors, and processing methods implemented by the worldwide space agencies nowadays. Hence, the precise definition of a standard is fundamental in order to prepare the InSAR data as one potential source of geospatial data and information, especially for LSTM data production. Generated time series of Digital Elevation Model (DEM) can identify the potential cause of 2018’s Sunda Strait tsunami (Tampubolon, 2019). It was related with the increasing eruption activity of Anak Krakatau (Child of Krakatoa). From DEM analysis, the Volcanic mudflow material avalanche has been detected before the tsunami hit the coastal surrounding area. In this paper, more advanced techniques was investigated by the combination between Time Series DEM Analysis and Ground Displacement detection. The focus on the integration between reliable TanDEM-X and up-to-date Sentinel 1A/B was proposed on another volcano island of Gamalama in Ternate. As TanDEM-X uses X-band as its medium wave, it can produce more reliable DEM as a reference data. On the other hand, Sentinel 1 uses C-band that can contribute to detect the ground deformation over the aforementioned volcano island. TanDEM-X uses a more robust and consistent approach to scan the earth surface by single data acquisition scheme, which is generally more accurate and reliable for the DEM generation. However, many factors influence the selection of a platform that can be best suited for radar interferometry. Initially, the German TanDEM-X Coregistered Singlelook Slant-range Complex (CoSSC) using bi-static InSAR approach has been implemented in order to generate DEMs comply with the LSTM specification in Indonesia. The basic principle is performing a simultaneous measurement of the same scene and identical doppler spectrum by using 2 sensors, thereby avoiding temporal decorrelation (DLR, 2012). Subsequently, the differential InSAR techniques by using Sentinel 1A/B has been performed in order to detect the ground deformation. Finally, tt can be shown that the reliable TanDEM-X data has increased the ground deformation resolution and accuracy in order to provide potential solution for disaster preparedness.

A MODEL OF COLLABORATIVE THEMATIC DEVELOPMENT OF EDUCATIONAL PROGRAMS IN THE FIELD OF GEOMATICS

In the last half-century, the knowledge and understanding of the problems generated by the climate variations have been facilitated by a spectacular evolution of monitoring techniques based on evolved means of acquisition, processing and interpretation of geospatial data. In parallel, but at a slower pace, the training methods specific to geomatics were given due importance in education. Faced with the real needs to process geospatial data applied to agriculture and the environment and the opportunities of creating many jobs in the sector of spatial environmental information, universities need teachers. But, in a large number of cases, they have been formed imperfectly and sometimes convey an approximate and questionable formation. Therefore, it is essential to establish a solid quality training based on an original approach in geomatics applied to agriculture, environment and sustainable development. The ERASMUS+ project “Capacity building in the field of geomatics applied to agriculture and environment in Tunisia (GEOMAG)” is an example of a modern approach to the way of effective training, developed in synergy with the rapid progress of the geospatial domain.

Development of Geospatial Data Acquisition, Modeling, and Service Technology for Digital Twin Implementation of Underground Utility Tunnel

In the maintenance domain of the construction industry, digital twins have been actively introduced based on the technologies of the Fourth Industrial Revolution with growing interest in three-dimensional spatial information facility management and disaster response service using digital twin technology. In particular, disasters or abnormal situations in an underground utility tunnel (UTU) can cause serious casualties and property damage since key elements of a city such as power, communications, water supply, and heating facilities are collectively accommodated in a certain underground space. This study established the methodology for implementing an underground utility tunnel through a digital twin. The novelty of this study is demonstrating a sequential procedure of implementing digital twin technology by configuring major layers such as data acquisition, modeling, and service. This methodology can serve as reference material or a training aid for implementing a digital twin of underground facilities or underground utility tunnels in the future; the proposed methodology will be verified when an actual digital twin service is provided.

UAV and TLS point cloud integration for the surface plant infrastructure of underground coal mines

The surface plant infrastructure (SPI) of underground coal mines is one of important sets of underground mines as it includes essential objects, such as office buildings, structures and equipment used to load, receive, sort or process minerals; receive and discharge waste rocks; provide ventilation for tunnels and energy for mining operations. The measurement and collection of spatial data of SPI are important to ensure the safe and effective management and operation of mining activities in underground mines. A rapid development in geospatial technologies has facilitated the acquisition of geospatial data in the mining industry. Unmanned Aerial Vehicle (UAV) photogrammetry and Terrestrial Laser Scanning (TLS) are two of the typical geospatial technologies, which have made significant contributions to the field of geospatial data collection. While UAV photogrammetry allows to create dense point clouds with centimeter - level accuracy in a short time and large areas, TLS technology can produce dense point clouds with millimeter - level accuracy. However, the latter is time - consuming and expensive while performing on a large area. The integration of UAV and TLS data can be seen as a reasonable solution to gain the advantages of both and avoid the disadvantages of each technology. This paper presents the results of an integrated study of point cloud data generated by UAV and TLS for the plant infrastructure of the underground coal mine. Featuring structures in the study area include mineshaft tower, office and factory buildings. The results show that the UAV and TLS integrated point cloud data has millimeter - level accuracy for important objects such as mineshaft towers, while ancillary structures in the study area have centimeter - level accuracy.

RANGE-BASED NETWORK FORMATION TO SUPPORT GEOREFERENCING OF MAPPING SWARM PLATFORMS

Abstract. Mapping platforms jointly operating in a formation are increasingly used to improve the efficiency of geospatial data acquisition recently. For example, UAS swarm mapping is gaining market share or robot platform are used for indoor mapping. These platforms are typically equipped with imaging and navigation sensors as well as have various communication capabilities. Until now, the platforms are individually navigated and georeferenced. Since the platforms are typically sharing a small area, and thus, they are within their sensing range; for example, they can see and thus track each other in optical or lidar imagery. Furthermore, new communication technologies have started to provide ranging information between communication points. Using the ranges between platforms makes it feasible to create a local geodetic network defined by the platforms. The geometric strength of the network then can be exploited to support platform georeferencing. In this study, the network formation based on ranges is investigated. Initial experiences are reported on the impact of the size of the network, the spatial distribution of the network nodes and the number of available ranges.

Acceleration of Human Resource Development for the UAV data processing in Indonesia

Abstract. Geospatial Information (GI) utilization needs acceleration in conjunction with the unprecedented improvement of GI technology infrastructures. Unmanned Aerial Vehicles (UAV) is one instance that demonstrates some advantages by enabling on demand flexible geospatial data acquisition. However due to the frequent use of non-metric camera such as consumer grade cameras, it requires the calibration procedure in order to fulfil the acceptable geometrical accuracy. The relatively simple procedures and high resolution produced data are the major advantages of the UAV data acquisition. With a land area approximately five times of the Federal Republic of Germany, the provision of GI in Indonesia requires innovative acceleration strategies that also considers cost production efficiency moreover due to the preparation of human resource in GI as its primary component. In this case, certification and accreditation in GI area are still mandatory especially in conjunction with technological improvements and weather situation (cloud coverage) as the main constraints to be considered for the geodata acquisition in Indonesia. This process includes knowledges, skills and/or advancements as well as working behaviour relevant with the tasks and conditions in a so-called Competency Working Standards of Indonesia (SKKNI). In addition to the SKKNI, GI competency standards can also use relevant international standards or specific standards as a reference. Competency standards are the basic requirements for any activities related with the national GI provision. Based on analysis of the national interests, the qualification identifications can be performed by specific study in the context of business process and GI industry from the scope of above mentioned national/international view as well as particular (GI) industry.Finally, this paper discusses and formulates the competency standards that can be used by corresponding stakeholders involved in the national GI provision from the actual regulation as well as technological/industrial perspectives. The standards of GI empowerments are fundamental especially in a situation where there are various technology and method available in the society as well as GI industry. For this purpose, the proper professional certification must be essentially well defined in order to prepare excellent GI human resources as the primary source for the provision of reliable GI data and information in a favour of the Large Scale Topographic Mapping (LSTM) and Updating acceleration program.

SURFACE APPROXIMATION OF COASTAL REGIONS: LR B-SPLINE FOR DETECTION OF DEFORMATION PATTERN

Abstract. Geospatial data acquisition of terrains produces huge, noisy and scattered point clouds. An efficient use of the acquired data requires structured and compact data representations. Working directly in a point cloud is often not appealing. To face this challenge, approximation with tensor product B-spline surfaces is attractive. It reduces the point cloud description to relatively few coefficients compared to the volume of the original point cloud. However, this representation lacks the ability to adapt the resolution of the shape to local variations in the point cloud. The result is frequently that noise is approximated and that surfaces have unwanted oscillations.Locally Refined (LR) B-spline surfaces were introduced to face this challenge and provide a tool for approximating Geographic Information System point clouds. In our LR B-spline based approximation algorithm, iterative least-squares approximation is combined with a Multilevel B-spline Approximation to reduce memory consumption. We apply the approach to data sets from coastal regions in Norway and the Netherlands, and compare the obtained approximation with a raster method. We further highlight the potential of LR B-spline volumes for spatio-temporal visualisation of deformation patterns.

A novel scheme for processing FMCW-ladar data acquired with low sampling rate

ABSTRACT The frequency-modulated continuous wave (FMCW) ladar is a useful sensor for remote sensing applications and has been widely used in both the military and civilian fields for precise geospatial data acquisition. Typically, the FMCW-ladar signal is collected by use of the heterodyne detection through the dechirping so as to decrease the sampling rate commensurate with the bandwidth. In this manuscript, we proposed a novel scheme for processing the FMCW-ladar signal acquired through the simplified heterodyne detection, and the sampling rate was the same as that in the dechirp detection. Based on the time–frequency relation of the FMCW-ladar signal, two algorithms were proposed to post-process the echo acquired by the simplified heterodyne detection with the sub-Nyquist sampling rate. For the FMCW-ladar echo data acquired by the simplified heterodyne detection with the same sampling rate as in the traditional dechirp detection, the algorithms can achieve the unambiguous range image retaining the range resolution commensurate with the transmitted chirp bandwidth. The effectiveness of the scheme was validated by simulation and real data processing experiments. The capability of the proposed scheme provides an alternative for the FMCW-ladar system without use of the dechirp detection, which can benefit the future FMCW-ladar and microwave photonics radar applications in the remote sensing.

A Risk-Based Approach for Enhancing the Fitness of Use of VGI

Volunteered Geographic Information (VGI) phenomena offer an alternative or supplement to the authoritative mechanism of geospatial data acquisition. It aims to allow people without professional geospatial skills or knowledge to participate in the geospatial data collection. VGI has been boosted by recent advances in geospatial technology and applications. VGI applications have shown great potential in various areas such as disaster management and public health. However, VGI suffers from a lack of quality assurance, because VGI contributors may lack knowledge of the geospatial domain and credibility. Moreover, VGI data may have different levels of detail and precision, and may have been collected for different purposes. Appropriate VGI data for a specific application may be less appropriate for another application. End-users may use VGI data without being aware of its appropriateness to their requirements. This may cause a risk that arises when end-users inappropriately use, or be uncertain about using VGI data in their applications. This risk may undermine the VGI project, in which end-users are involved. This paper proposes an approach that aims to enhance VGI quality assurance by measuring the spatio-semantic similarity between user requirements and provided VGI, and to evaluate the fitness-for-use of VGI. The proposed approach is based on an algorithm to help VGI end-users to deal with the risks related to the quality of VGI data. The approach helps end-user make appropriate decisions about VGI data (e.g., considering or not considering VGI data and being careful when using VGI data).

IPHONE 13 PRO VS PROFESSIONAL TLS FOR 3D INDOOR MAPPING

<jats:p>In recent years, fast and simple acquisition of geospatial data, fast processing, and distribution is a trend that characterizes geoinformation technologies. The primacy of the acquisition is based on image processing technology and laser scanning. This paper attempts to answer how acceptable these technologies are incorporated into smartphones which can be used for data acquisition. A comparative analysis of the results collected by smartphone and professional laser scanners has been made. The results presented in the paper confirm the usability of the iPhone LiDAR device in the acquisition of point cloud and the development of 3D models of indoor spaces.</jats:p>

Pyramidal Framework: Guidance for the Next Generation of GIS Spatial-Temporal Models

Over the last decade, innovative computer technologies and the multiplication of geospatial data acquisition solutions have transformed the geographic information systems (GIS) landscape and opened up new opportunities to close the gap between GIS and the dynamics of geographic phenomena. There is a demand to further develop spatio-temporal conceptual models to comprehensively represent the nature of the evolution of geographic objects. The latter involves a set of considerations like those related to managing changes and object identities, modeling possible causal relations, and integrating multiple interpretations. While conventional literature generally presents these concepts separately and rarely approaches them from a holistic perspective, they are in fact interrelated. Therefore, we believe that the semantics of modeling would be improved by considering these concepts jointly. In this work, we propose to represent these interrelationships in the form of a hierarchical pyramidal framework and to further explore this set of concepts. The objective of this framework is to provide a guideline to orient the design of future generations of GIS data models, enabling them to achieve a better representation of available spatio-temporal data. In addition, this framework aims at providing keys for a new interpretation and classification of spatio-temporal conceptual models. This work can be beneficial for researchers, students, and developers interested in advanced spatio-temporal modeling.

The utility of earth science information in post-earthquake land-use decision-making: the 2010–2011 Canterbury earthquake sequence in Aotearoa New Zealand

Abstract. Earth science information (data, knowledge, advice) can enhance the evidence base for land-use decision-making. The utility of this information depends on factors including the context and objectives of land-use decisions, the timeliness and efficiency with which earth science information is delivered, and the strength, relevance, uncertainties, and risks assigned to earth science information relative to other inputs. We investigate land-use decision-making practices in Christchurch, New Zealand, and the surrounding region in response to mass movement (e.g., rockfall, cliff collapses) and ground-surface fault rupture hazards incurred during the 2010–2011 Canterbury earthquake sequence (CES). Rockfall fatality risk models combining hazard, exposure, and vulnerability data were co-produced by earth scientists and decision makers and formed primary evidence for risk-based land-use decision-making with adaptive capacity. A public consultation and submission process enabled consideration of additional earth science information primarily via stakeholder requests. For fault rupture hazards, pre-disaster geotechnical guidelines and collaboration networks enhanced the ability of earth scientists to rapidly acquire relevant observational data to meet the demands of decision makers. Expeditious decision-making granted permissive consent for rebuilding in the fault rupture zone based on preliminary scientific advice that was subsequently supported by more comprehensive geological investigations. Rapidly fluctuating and diverse demands for post-disaster earth science information may be best met through the prior establishment of (i) land-use policies and technical guidelines tailored for a variety of diverse disaster scenarios, (ii) hazard and risk analyses in land-use plans, including acquisition of geospatial and other earth science data, and (iii) coordinated scientific networks that may comprise subgroups with diverse goals, operational perspectives, and protocols which allow the many facets of scientific information acquisition and delivery to be successfully addressed. Despite the collective knowledge shared here, some recent land-use practices in New Zealand continue to prioritize other (e.g., socioeconomic) factors above earth science information, even in areas of extreme disaster risk.

QUALITY CONTROL RELEVANCE ON ACQUISITION OF LARGE SCALE GEOSPATIAL DATA TO URBAN TERRITORIAL MANAGEMENT

Abstract. Quality control (QC) of geospatial data is relevant to urban territorial management to ensure accurate data for government to make strategic decisions when planning cities. The acquisition and control of geospatial data in the Brazilian government must follow INDE - National Data Spatial Infrastructure - through the Technical Specifications. The cadastral cartography from urban areas in Brasilia was updated and divided into 10 areas. Acquired data includes classes, features, attributes and metadata on 1:1,000 scale. High resolution images and LIDAR data were used to assist the QC process. The first step of the QC was to check positional accuracy. Samples were applied for each class in the mapping block with 4% rate on the feature random selection and all features class had the same level of confidence. Then, three stages were automatically verified: logical consistency, commision and attribute thematic accuracy evaluations. The process also includes the visual interpretation for omission and classification, which involves a certain subjectivity. Everything was executed with QGIS, FME, Erdas Imagine, Postgresql, PostGIS and a plugin specifically developed for that, the DSGTools. The results show that in general, the quantity of errors were low. However, many errors were detected in the elements completeness and thematic accuracy, specially in áreas 1, 2, 3, 6 and 9. In the opposite, the logical consistency and positional accuracy presented the lowest quantity of errors, which does not diminish the relevance of these errors, since it compromises the usability of the data.

Spatial ETL for 3D Building Modelling Based on Unmanned Aerial Vehicle Data in Semi-Urban Areas

This paper provides the innovative approach of using a spatial extract, transform, load (ETL) solution for 3D building modelling, based on an unmanned aerial vehicle (UAV) photogrammetric point cloud. The main objective of the paper is to present the holistic workflow for 3D building modelling, emphasising the benefits of using spatial ETL solutions for this purpose. Namely, despite the increasing demands for 3D city models and their geospatial applications, the generation of 3D city models is still challenging in the geospatial domain. Advanced geospatial technologies provide various possibilities for the mass acquisition of geospatial data that is further used for 3D city modelling, but there is a huge difference in the cost and quality of input data. While aerial photogrammetry and airborne laser scanning involve high costs, UAV photogrammetry has brought new opportunities, including for small and medium-sized companies, by providing a more flexible and low-cost source of spatial data for 3D modelling. In our data-driven approach, we use a spatial ETL solution to reconstruct a 3D building model from a dense image matching point cloud which was obtained beforehand from UAV imagery. The results are 3D building models in a semantic vector format consistent with the OGC CityGML standard, Level of Detail 2 (LOD2). The approach has been tested on selected buildings in a simple semi-urban area. We conclude that spatial ETL solutions can be efficiently used for 3D building modelling from UAV data, where the data process model developed allows the developer to easily control and manipulate each processing step.

Potentials of UAV Remote Sensing Data Carrier – A Case of Application in UAV Low Altitude Route—planning

Unmanned aerial vehicles (UAVs) are commonly applied for low-altitude remote sensing, and their effective flights generate a large amount of remote sensing data in centimeter-level resolution every day. UAV remote sensing has become an important new source for generating geographic big data. However, UAV remote sensing data is multi-source heterogeneous and disordered in management. To scientifically manage and maximize the utilization of UAV remote sensing data, the “UAV remote sensing data carrier” has been proposed. It features distribution of remote sensing tasks and exchange of rich datasets for various UAVs owned by individuals or organizations and thus has great application potential in low altitude with complex artificial and natural environments. The UAV low-altitude public air route is a commonly recognized solution to enable safe flights of UAVs in low altitude, which requires a variety of precise geographic data. Therefore, the UAV remote sensing data carrier can contribute to the construction of low-altitude public air routes. It can realize the three-dimensional geospatial data acquisition and dynamic information updates on routes, the service to route construction in various industries, and the support of real-time optimal path selection. Construction of low-altitude public air routes based on the carrier have already been applied in the UAV cloud regulation system “SkyGrid”, which is currently inadequately studied. Besides route construction, the carrier has great potential for further development of low-altitude airspace resources and reasonable use applications.