UAV-g 2019: Unmanned Aerial Vehicles in Geomatics

Abstract

Unmanned aerial vehicle in geomatics (UAV-g) is a well-established scientific event dedicated to UAVs in geomatics and remote sensing. In the different editions of the journal, new scientific challenges have increased their synergy with adjacent domains, such as robotics and computer vision, thereby increasing the impact of this conference. The 2019 edition has been hosted by the University of Twente (The Netherlands) and has attracted about 300 participants for the full three-day program. Researchers from 36 different countries (from all continents) have presented 89 accepted papers in 17 oral and 2 poster sessions. The presented papers covered multi-disciplinary topics, such as photogrammetry, natural resources monitoring, autonomous navigation, and deep learning. All these contributions have in common the use of UAV platforms for the innovative acquisition and processing of the acquired data and information extracted from the surrounding environment.

1. The 2019 Edition

Unmanned aerial vehicles (UAVs or ‘drones’) have become popular instruments for a wide range of emerging applications, such as mapping, search and rescue, infrastructure monitoring, precision farming, the transport of goods, and film-making. The UAV market has been valued at more than 100 US$ billion and the outlook is extremely promising for subsequent years. The economic boom has boosted the scientific and technological development of UAV technologies in the last decade, as demonstrated by the growing number of scientific works dealing with this technology.

In this context, UAV-g was initiated in 2011 in Zurich as the ISPRS (International Society of Photogrammetry and Remote Sensing) scientific event dedicated to UAVs in geomatics and remote sensing. Three other editions took place in Rostock (2013), Toronto (2015), and Bonn (2017), making UAV-g a well-established and recognized event, even outside the ISPRS community. In the various editions, new scientific challenges and technological developments have made explicit the need for an inter-disciplinary approach, leading to stronger synergies with adjacent disciplines, such as robotics and computer vision.

UAV-g 2019 took place on 10–12 June 2019. For the first time in its history, UAV-g was hosted during the ISPRS Geospatial Week (GSW, www.gsw2019.org), reaching a larger audience involved in various remote sensing disciplines. Its setting at the University of Twente (Enschede, The Netherlands) campus (along with its facilities) enabled demonstrations and exhibitions related to recent developments in unmanned platform technologies.

UAV-g 2019 brought together experts from different domains. Besides experts in remote sensing and geoscience, researchers from robotics, computer vision, and artificial intelligence joined this event. This multidisciplinary environment was also reflected in the scientific committee, composed of 33 experts with very different areas of expertise and working in 16 countries all over the world.

The paper submission was successful: 120 papers were initially submitted, and 89 of them were accepted after the scientific committee revision process; 15 ISPRS Annals and 74 Archives papers were published on the ISPRS website. The received papers reflect the multidisciplinary nature of the event, ranging from the study of the natural environment to on-board sensor development and autonomous navigation. The keywords of the published papers are summarized in Figure 1. These contributions have also confirmed the relevance of UAV technology worldwide: 36 different countries from five continents were represented in the list of the papers’ authors (Figure 2).

A total of 17 oral sessions (four plenary and the others in parallel) were organized in the three full day program. Two poster sessions and a session dedicated to European H2020 projects dealing with the developments of UAV studies were also organized. An overview of these sessions is provided in Section 2.

Three invited speakers presented the newest developments and trends in different aspects of the UAV domain. Edward Anderson (https://www.gsw2019.org/speaker/edward-anderson-world-bank/) (opening keynote of the ISPRS Geospatial week) gave a presentation on the use of new technologies (such as UAVs and artificial intelligence) for urban resilience in Africa. Pablo Zarco-Tejada (https://www.gsw2019.org/speaker/pablo-zarco-tejada-the-university-of-melbourne/) presented on the recent trends in the use of UAVs for precision agriculture and forestry monitoring. Margarita Chli (https://www.gsw2019.org/speaker/margarita_chli/) (joint keynote with parallel other conferences) showed how vision-based perception is boosting the intelligence of flying robots.

The presence of 20 sponsors at the ISPRS GeoSpatial Week (https://www.gsw2019.org/sponsors-2/), many of them operating in the UAV domain, further confirmed that UAV-g is a relevant event to create synergy, learn about recent developments, and exchange views on the future directions of UAV research, applications, and services. In this regard, the Drones MDPI journal sponsored the UAV-g Best Paper Award.

The advertisements through the conference website (www.uav-g.com) and the Twitter and Facebook account increased the interest for the ISPRS Geospatial Week that had about 750 registrations, while UAV-g received about 300 participants.

2. Oral Sessions

The oral sessions were organized according to different areas that can be summarized as three main topics: (i) photogrammetry and geomatics developments, (ii) natural resources and environmental applications, and (iii) synergies with robotics and computer vision. In the following sections, a detailed explanation of the sessions hosted in each of these thematic areas will be given.

2.1. Geomatics Developments in UAV

Under this topic area, six sessions were organized on the use of UAV in photogrammetry and geomatics applications, in line with the long tradition of the UAV-g conference. In the two sessions on UAV photogrammetry, the contributions investigated the accuracy of image orientation [1] and the geometric quality of the generated point clouds [2,3,4,5], showing how the accuracy of photogrammetric products can be influenced by different image configurations, sensors, and software. The investigation of new devices, such as RTK receivers on low cost drones, were then discussed in other contributions [6,7,8,9], highlighting the remaining problems of these techniques and suggesting the best practices to be followed. The integration of different sensors on-board a UAV [10] and the adoption of new sensors, such as spherical cameras [11], showed the larger flexibility of the newest platforms to host several sensors with (often) relevant sizes. Other contributions showed how UAV data can be integrated together [10,12] or embedded in multi-source systems [13,14] to build larger and more complex solutions. This edition of UAV-g was also characterized by the increased number of contributions dealing with the use of LiDAR [15,16,17,18] and SAR [19] sensors. Lastly, relevant contributions were presented on the inclusion of UAVs in university education and policy [20,21].

2.2. Natural Resources and Environmental Uses of UAVs

The increased interest in the use of UAVs for environmental monitoring has been confirmed by the larger number of contributions dealing with precision farming and environmental monitoring. This led to two sessions on precision farming, two sessions on agriculture and forest monitoring, one session on environmental monitoring, and another on emergency and natural hazards. In the precision farming sessions, studies on the detection of different crop species [22,23,24], prediction of biomass [25], or other relevant characteristics, such as phenotype [26], structure [27], and dimensions [28,29], were presented. The agriculture and forest monitoring sessions gave the opportunity to understand the most recent developments in tree species classifications [30,31] and in the estimation of parameters like crop height [32,33,34] and other morphometric properties [35]. The session on environmental monitoring showed how UAVs are, today, commonly adopted for monitoring applications, such as the detection of water bodies [36], glaciers [37], animals [38,39], and temperature profiles [40]. UAVs are also becoming a valuable instrument for emergency management, as shown. Examples on the use of UAVs for monitoring and mapping natural hazards like landslides [41], earthquakes [42,43,44], and flooding [45] were presented.

2.3. Synergies with Robotics and Computer Vision in the Use of UAVs

Studies in robotics, computer vision, and geomatics often have parallel paths and have led to synergy and collaboration in the last few years. Deep learning algorithms initially developed in computer vision are also becoming the standard in remote sensing. The development of autonomous navigation is gaining attention not only in robotics but also in mapping applications. The use of innovative sensors for data acquisition and processing, as well as their integration in more flexible solutions, have attracted the attention of all these communities in recent years. One session on UAV flight planning and navigation, one session on autonomous navigation, and two sessions on scene understanding using UAV data were organized during the conference. Different flight planning approaches were proposed to face critical acquisitions [46,47,48] and produce more reliable products [49,50]. Recent improvements on simultaneous localization and mapping (SLAM) algorithms [51,52], as well as the new integration of different sensors for autonomous navigation in indoor environments [53,54,55], were shown in a dedicated session. The recent developments in deep learning applied to UAV data and remote sensing applications were presented. These developments showed the potential of these algorithms in different applications, such as tree classifications [56,57,58], map generation [59], localizations [60], and real-time monitoring [61,62].

3. Poster Sessions

Two poster sessions were hosted on two different days of the conference. Well organized and self-explicative posters were produced by authors presenting works on different topics [63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89]. The poster sessions presented an important opportunity to debate conference topics and networking with researchers and experts in the UAV domain.

4. Best Paper Award 2019

Two awards were assigned for the best paper and the best poster, respectively. The best paper award (offered by Drones, MDPI) was assigned to [30] according to the scores received by the scientific committee during the revision process. The best poster award (offered by Whittles publisher) was assigned to [69] after the assessment of a panel composed of selected members of the scientific committee.

5. Next Edition in 2021

Almost two months before the conference, a call was opened to bid for the organization of the 2021 edition. The committee received four different applications from three different continents, confirming the great interest of the scientific community in this event. Each of these candidate hosting institutions was invited to present its proposal in front of the scientific committee and the ISPRS Council. The vote of this panel assigned the organization of UAV-g 2021 to the Inha University (Icheon, South Korea), with Prof. Taejung Kim acting as conference chair.