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Special Issue "Sensors and Techniques for 3D Object Modeling in Underwater Environments"

A special issue of Sensors (ISSN 1424-8220).

Deadline for manuscript submissions: closed (31 October 2015)

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Guest Editor
Dr. Fabio Menna

3D Optical Metrology Unit, Bruno Kessler Foundation, Trento, Italy
Website | E-Mail
Interests: photogrammetry, laser scanning, 3D surveying, navigation, 3D modeling, reverse engineering
Guest Editor
Dr. Fabio Remondino

3D Optical Metrology unit, Bruno Kessler Foundation, Trento, Italy
Website | E-Mail
Fax: +39 0461 314340
Interests: photogrammetry; laser scanning; 3D reconstruction; 3D modeling; sensor integration
Guest Editor
Prof. Dr. Hans-Gerd Maas

Institute of Photogrammetry and Remote Sensing, TU Dresden, Dresden, Germany
Website | E-Mail
Interests: photogrammetry, laser scanning, 3D reconstruction, sensor characterization, multimedia applications

Special Issue Information

Dear Colleagues,

Water covers approximately 71% of the planet’s surface and human activities have been relying on it since remote times. Many traces of these exist under the “zero level” and will continue to exist in the future. Measuring, positioning, and mapping objects under water have experienced very significant modifications, brought about by advances in technology and also by changed requirements, demands for new products, introduction of new tools, and the modification of existing equipment. The exploration, documentation, and recording of underwater environments remains a difficult task, and is sometimes still unsolved. The research, design, and development of techniques and procedures for correctly validating underwater environments are more than ever important.

This Special Issue originates from the ISPRS/CIPA Workshop "UNDERWATER 3D RECORDING & MODELING—Experiences in Data Acquisition, Calibration, Orientation, Modelling & Accuracy Assessment” (http://3dom.fbk.eu/files/underwater/index.html) and will accept improved and extended selected papers derived from the workshop’s proceedings, as well as new contributions from international colleagues.

We invite you to submit articles on the following topics:

  • Underwater/Multi-media photogrammetry
  • Underwater platforms (ROV, AUV, robot, etc.)
  • Characterization of underwater passive and active sensors
  • Underwater navigation and positioning
  • Underwater metrology and inspections
  • Geometric modeling in multi-media photogrammetry
  • Accuracy requirement and assessment in underwater 3D applications
  • Restoration, enhancement and processing of underwater images
  • 3D bathymetry techniques
  • Data processing and underwater 3D modeling
  • Sensors for marine biology and water pollution
  • Multi-sensor integration

Dr. Fabio Menna
Dr. Fabio Remondino
Prof. Hans-Gerd Maas
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sensors is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.


Keywords

  • Underwater
  • Photogrammetry
  • Bathymetry
  • ROV
  • 3D modelling
  • Multi-media
  • Marine biology

Published Papers (13 papers)

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Research

Jump to: Review

Open AccessArticle An Alignment Method for the Integration of Underwater 3D Data Captured by a Stereovision System and an Acoustic Camera
Sensors 2016, 16(4), 536; doi:10.3390/s16040536
Received: 31 October 2015 / Revised: 5 April 2016 / Accepted: 8 April 2016 / Published: 14 April 2016
Cited by 5 | PDF Full-text (8664 KB) | HTML Full-text | XML Full-text
Abstract
The integration of underwater 3D data captured by acoustic and optical systems is a promising technique in various applications such as mapping or vehicle navigation. It allows for compensating the drawbacks of the low resolution of acoustic sensors and the limitations of optical
[...] Read more.
The integration of underwater 3D data captured by acoustic and optical systems is a promising technique in various applications such as mapping or vehicle navigation. It allows for compensating the drawbacks of the low resolution of acoustic sensors and the limitations of optical sensors in bad visibility conditions. Aligning these data is a challenging problem, as it is hard to make a point-to-point correspondence. This paper presents a multi-sensor registration for the automatic integration of 3D data acquired from a stereovision system and a 3D acoustic camera in close-range acquisition. An appropriate rig has been used in the laboratory tests to determine the relative position between the two sensor frames. The experimental results show that our alignment approach, based on the acquisition of a rig in several poses, can be adopted to estimate the rigid transformation between the two heterogeneous sensors. A first estimation of the unknown geometric transformation is obtained by a registration of the two 3D point clouds, but it ends up to be strongly affected by noise and data dispersion. A robust and optimal estimation is obtained by a statistical processing of the transformations computed for each pose. The effectiveness of the method has been demonstrated in this first experimentation of the proposed 3D opto-acoustic camera. Full article
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Open AccessArticle DeepSurveyCam—A Deep Ocean Optical Mapping System
Sensors 2016, 16(2), 164; doi:10.3390/s16020164
Received: 1 November 2015 / Revised: 20 January 2016 / Accepted: 22 January 2016 / Published: 28 January 2016
Cited by 3 | PDF Full-text (3344 KB) | HTML Full-text | XML Full-text
Abstract
Underwater photogrammetry and in particular systematic visual surveys of the deep sea are by far less developed than similar techniques on land or in space. The main challenges are the rough conditions with extremely high pressure, the accessibility of target areas (container and
[...] Read more.
Underwater photogrammetry and in particular systematic visual surveys of the deep sea are by far less developed than similar techniques on land or in space. The main challenges are the rough conditions with extremely high pressure, the accessibility of target areas (container and ship deployment of robust sensors, then diving for hours to the ocean floor), and the limitations of localization technologies (no GPS). The absence of natural light complicates energy budget considerations for deep diving flash-equipped drones. Refraction effects influence geometric image formation considerations with respect to field of view and focus, while attenuation and scattering degrade the radiometric image quality and limit the effective visibility. As an improvement on the stated issues, we present an AUV-based optical system intended for autonomous visual mapping of large areas of the seafloor (square kilometers) in up to 6000 m water depth. We compare it to existing systems and discuss tradeoffs such as resolution vs. mapped area and show results from a recent deployment with 90,000 mapped square meters of deep ocean floor. Full article
Open AccessArticle Geometric and Optic Characterization of a Hemispherical Dome Port for Underwater Photogrammetry
Sensors 2016, 16(1), 48; doi:10.3390/s16010048
Received: 10 November 2015 / Accepted: 26 December 2015 / Published: 2 January 2016
Cited by 2 | PDF Full-text (6123 KB) | HTML Full-text | XML Full-text
Abstract
The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is
[...] Read more.
The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is fundamental to better plan field campaigns and anticipate the achievable results. The paper presents a geometric investigation of a consumer grade underwater camera housing, manufactured by NiMAR and equipped with a 7′′ dome port. After a review of flat and dome ports, the work analyzes, using simulations and real experiments, the main optical phenomena involved when operating a camera underwater. Specific aspects which deal with photogrammetric acquisitions are considered with some tests in laboratory and in a swimming pool. Results and considerations are shown and commented. Full article
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Open AccessArticle Integrating Sensors into a Marine Drone for Bathymetric 3D Surveys in Shallow Waters
Sensors 2016, 16(1), 41; doi:10.3390/s16010041
Received: 31 October 2015 / Revised: 21 December 2015 / Accepted: 24 December 2015 / Published: 29 December 2015
Cited by 2 | PDF Full-text (12517 KB) | HTML Full-text | XML Full-text
Abstract
This paper demonstrates that accurate data concerning bathymetry as well as environmental conditions in shallow waters can be acquired using sensors that are integrated into the same marine vehicle. An open prototype of an unmanned surface vessel (USV) named MicroVeGA is described. The
[...] Read more.
This paper demonstrates that accurate data concerning bathymetry as well as environmental conditions in shallow waters can be acquired using sensors that are integrated into the same marine vehicle. An open prototype of an unmanned surface vessel (USV) named MicroVeGA is described. The focus is on the main instruments installed on-board: a differential Global Position System (GPS) system and single beam echo sounder; inertial platform for attitude control; ultrasound obstacle-detection system with temperature control system; emerged and submerged video acquisition system. The results of two cases study are presented, both concerning areas (Sorrento Marina Grande and Marechiaro Harbour, both in the Gulf of Naples) characterized by a coastal physiography that impedes the execution of a bathymetric survey with traditional boats. In addition, those areas are critical because of the presence of submerged archaeological remains that produce rapid changes in depth values. The experiments confirm that the integration of the sensors improves the instruments’ performance and survey accuracy. Full article
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Open AccessArticle Underwater 3D Surface Measurement Using Fringe Projection Based Scanning Devices
Sensors 2016, 16(1), 13; doi:10.3390/s16010013
Received: 30 October 2015 / Revised: 11 December 2015 / Accepted: 18 December 2015 / Published: 23 December 2015
Cited by 5 | PDF Full-text (6622 KB) | HTML Full-text | XML Full-text
Abstract
In this work we show the principle of optical 3D surface measurements based on the fringe projection technique for underwater applications. The challenges of underwater use of this technique are shown and discussed in comparison with the classical application. We describe an extended
[...] Read more.
In this work we show the principle of optical 3D surface measurements based on the fringe projection technique for underwater applications. The challenges of underwater use of this technique are shown and discussed in comparison with the classical application. We describe an extended camera model which takes refraction effects into account as well as a proposal of an effective, low-effort calibration procedure for underwater optical stereo scanners. This calibration technique combines a classical air calibration based on the pinhole model with ray-based modeling and requires only a few underwater recordings of an object of known length and a planar surface. We demonstrate a new underwater 3D scanning device based on the fringe projection technique. It has a weight of about 10 kg and the maximal water depth for application of the scanner is 40 m. It covers an underwater measurement volume of 250 mm × 200 mm × 120 mm. The surface of the measurement objects is captured with a lateral resolution of 150 μm in a third of a second. Calibration evaluation results are presented and examples of first underwater measurements are given. Full article
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Open AccessArticle Optical Sensors and Methods for Underwater 3D Reconstruction
Sensors 2015, 15(12), 31525-31557; doi:10.3390/s151229864
Received: 7 September 2015 / Revised: 2 December 2015 / Accepted: 4 December 2015 / Published: 15 December 2015
Cited by 5 | PDF Full-text (2673 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and
[...] Read more.
This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and a classification has been proposed for the existing solutions. New developments, commercial solutions and previous reviews in this topic have also been gathered and considered. Full article
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Open AccessArticle Adjustment of Sonar and Laser Acquisition Data for Building the 3D Reference Model of a Canal Tunnel
Sensors 2015, 15(12), 31180-31204; doi:10.3390/s151229855
Received: 30 October 2015 / Revised: 2 December 2015 / Accepted: 3 December 2015 / Published: 11 December 2015
Cited by 3 | PDF Full-text (12648 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is
[...] Read more.
In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is challenging because the sonar device is used in a narrow environment that induces many artifacts. Moreover, the location and the orientation of the sonar device are unknown. In our approach, sonar data are first simultaneously denoised and meshed. Then, above- and under-water point clouds are co-registered to generate directly the full 3D model of the canal tunnel. Faced with the lack of overlap between both models, we introduce a robust algorithm that relies on geometrical entities and partially-immersed targets, which are visible in both the laser and sonar point clouds. A full 3D model, visually promising, of the entrance of a canal tunnel is obtained. The analysis of the method raises several improvement directions that will help with obtaining more accurate models, in a more automated way, in the limits of the involved technology. Full article
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Open AccessArticle The Bubble Box: Towards an Automated Visual Sensor for 3D Analysis and Characterization of Marine Gas Release Sites
Sensors 2015, 15(12), 30716-30735; doi:10.3390/s151229825
Received: 1 November 2015 / Accepted: 1 December 2015 / Published: 5 December 2015
PDF Full-text (9872 KB) | HTML Full-text | XML Full-text
Abstract
Several acoustic and optical techniques have been used for characterizing natural and anthropogenic gas leaks (carbon dioxide, methane) from the ocean floor. Here, single-camera based methods for bubble stream observation have become an important tool, as they help estimating flux and bubble sizes
[...] Read more.
Several acoustic and optical techniques have been used for characterizing natural and anthropogenic gas leaks (carbon dioxide, methane) from the ocean floor. Here, single-camera based methods for bubble stream observation have become an important tool, as they help estimating flux and bubble sizes under certain assumptions. However, they record only a projection of a bubble into the camera and therefore cannot capture the full 3D shape, which is particularly important for larger, non-spherical bubbles. The unknown distance of the bubble to the camera (making it appear larger or smaller than expected) as well as refraction at the camera interface introduce extra uncertainties. In this article, we introduce our wide baseline stereo-camera deep-sea sensor bubble box that overcomes these limitations, as it observes bubbles from two orthogonal directions using calibrated cameras. Besides the setup and the hardware of the system, we discuss appropriate calibration and the different automated processing steps deblurring, detection, tracking, and 3D fitting that are crucial to arrive at a 3D ellipsoidal shape and rise speed of each bubble. The obtained values for single bubbles can be aggregated into statistical bubble size distributions or fluxes for extrapolation based on diffusion and dissolution models and large scale acoustic surveys. We demonstrate and evaluate the wide baseline stereo measurement model using a controlled test setup with ground truth information. Full article
Open AccessArticle Sinusoidal Wave Estimation Using Photogrammetry and Short Video Sequences
Sensors 2015, 15(12), 30784-30809; doi:10.3390/s151229828
Received: 26 October 2015 / Accepted: 30 November 2015 / Published: 5 December 2015
PDF Full-text (15388 KB) | HTML Full-text | XML Full-text
Abstract
The objective of the work is to model the shape of the sinusoidal shape of regular water waves generated in a laboratory flume. The waves are traveling in time and render a smooth surface, with no white caps or foam. Two methods are
[...] Read more.
The objective of the work is to model the shape of the sinusoidal shape of regular water waves generated in a laboratory flume. The waves are traveling in time and render a smooth surface, with no white caps or foam. Two methods are proposed, treating the water as a diffuse and specular surface, respectively. In either case, the water is presumed to take the shape of a traveling sine wave, reducing the task of the 3D reconstruction to resolve the wave parameters. The first conceived method performs the modeling part purely in 3D space. Having triangulated the points in a separate phase via bundle adjustment, a sine wave is fitted into the data in a least squares manner. The second method presents a more complete approach for the entire calculation workflow beginning in the image space. The water is perceived as a specular surface, and the traveling specularities are the only observations visible to the cameras, observations that are notably single image. The depth ambiguity is removed given additional constraints encoded within the law of reflection and the modeled parametric surface. The observation and constraint equations compose a single system of equations that is solved with the method of least squares adjustment. The devised approaches are validated against the data coming from a capacitive level sensor and on physical targets floating on the surface. The outcomes agree to a high degree. Full article
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Open AccessArticle Underwater Photogrammetry and Object Modeling: A Case Study of Xlendi Wreck in Malta
Sensors 2015, 15(12), 30351-30384; doi:10.3390/s151229802
Received: 20 October 2015 / Revised: 24 November 2015 / Accepted: 25 November 2015 / Published: 4 December 2015
Cited by 5 | PDF Full-text (8419 KB) | HTML Full-text | XML Full-text
Abstract
In this paper we present a photogrammetry-based approach for deep-sea underwater surveys conducted from a submarine and guided by knowledge-representation combined with a logical approach (ontology). Two major issues are discussed in this paper. The first concerns deep-sea surveys using photogrammetry from a
[...] Read more.
In this paper we present a photogrammetry-based approach for deep-sea underwater surveys conducted from a submarine and guided by knowledge-representation combined with a logical approach (ontology). Two major issues are discussed in this paper. The first concerns deep-sea surveys using photogrammetry from a submarine. Here the goal was to obtain a set of images that completely covered the selected site. Subsequently and based on these images, a low-resolution 3D model is obtained in real-time, followed by a very high-resolution model produced back in the laboratory. The second issue involves the extraction of known artefacts present on the site. This aspect of the research is based on an a priori representation of the knowledge involved using systematic reasoning. Two parallel processes were developed to represent the photogrammetric process used for surveying as well as for identifying archaeological artefacts visible on the sea floor. Mapping involved the use of the CIDOC-CRM system (International Committee for Documentation (CIDOC)—Conceptual Reference Model)—This is a system that has been previously utilised to in the heritage sector and is largely available to the established scientific community. The proposed theoretical representation is based on procedural attachment; moreover, a strong link is maintained between the ontological description of the modelled concepts and the Java programming language which permitted 3D structure estimation and modelling based on a set of oriented images. A very recently discovered shipwreck acted as a testing ground for this project; the Xelendi Phoenician shipwreck, found off the Maltese coast, is probably the oldest known shipwreck in the western Mediterranean. The approach presented in this paper was developed in the scope of the GROPLAN project (Généralisation du Relevé, avec Ontologies et Photogrammétrie, pour l'Archéologie Navale et Sous-marine). Financed by the French National Research Agency (ANR) for four years, this project associates two French research laboratories, an industrial partner, the University of Malta, and Texas A & M University. Full article
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Open AccessArticle Camera Calibration for Water-Biota Research: The Projected Area of Vegetation
Sensors 2015, 15(12), 30261-30269; doi:10.3390/s151229798
Received: 8 October 2015 / Revised: 27 November 2015 / Accepted: 30 November 2015 / Published: 3 December 2015
Cited by 3 | PDF Full-text (3004 KB) | HTML Full-text | XML Full-text
Abstract
Imaging systems have an indisputable role in revealing vegetation posture under diverse flow conditions, image sequences being generated with off the shelf digital cameras. Such sensors are cheap but introduce a range of distortion effects, a trait only marginally tackled in hydraulic studies
[...] Read more.
Imaging systems have an indisputable role in revealing vegetation posture under diverse flow conditions, image sequences being generated with off the shelf digital cameras. Such sensors are cheap but introduce a range of distortion effects, a trait only marginally tackled in hydraulic studies focusing on water-vegetation dependencies. This paper aims to bridge this gap by presenting a simple calibration method to remove both camera lens distortion and refractive effects of water. The effectiveness of the method is illustrated using the variable projected area, computed for both simple and complex shaped objects. Results demonstrate the significance of correcting images using a combined lens distortion and refraction model, prior to determining projected areas and further data analysis. Use of this technique is expected to increase data reliability for future work on vegetated channels. Full article
Open AccessArticle On the Accuracy Potential in Underwater/Multimedia Photogrammetry
Sensors 2015, 15(8), 18140-18152; doi:10.3390/s150818140
Received: 9 June 2015 / Revised: 30 June 2015 / Accepted: 9 July 2015 / Published: 24 July 2015
Cited by 4 | PDF Full-text (1350 KB) | HTML Full-text | XML Full-text
Abstract
Underwater applications of photogrammetric measurement techniques usually need to deal with multimedia photogrammetry aspects, which are characterized by the necessity of handling optical rays that are refracted at interfaces between optical media with different refractive indices according to Snell’s Law. This so-called multimedia
[...] Read more.
Underwater applications of photogrammetric measurement techniques usually need to deal with multimedia photogrammetry aspects, which are characterized by the necessity of handling optical rays that are refracted at interfaces between optical media with different refractive indices according to Snell’s Law. This so-called multimedia geometry has to be incorporated into geometric models in order to achieve correct measurement results. The paper shows a flexible yet strict geometric model for the handling of refraction effects on the optical path, which can be implemented as a module into photogrammetric standard tools such as spatial resection, spatial intersection, bundle adjustment or epipolar line computation. The module is especially well suited for applications, where an object in water is observed by cameras in air through one or more planar glass interfaces, as it allows for some simplifications here. In the second part of the paper, several aspects, which are relevant for an assessment of the accuracy potential in underwater/multimedia photogrammetry, are discussed. These aspects include network geometry and interface planarity issues as well as effects caused by refractive index variations and dispersion and diffusion under water. All these factors contribute to a rather significant degradation of the geometric accuracy potential in underwater/multimedia photogrammetry. In practical experiments, a degradation of the quality of results by a factor two could be determined under relatively favorable conditions. Full article

Review

Jump to: Research

Open AccessReview Calibration Techniques for Accurate Measurements by Underwater Camera Systems
Sensors 2015, 15(12), 30810-30826; doi:10.3390/s151229831
Received: 29 October 2015 / Revised: 30 November 2015 / Accepted: 1 December 2015 / Published: 7 December 2015
Cited by 12 | PDF Full-text (1168 KB) | HTML Full-text | XML Full-text
Abstract
Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof
[...] Read more.
Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems. Full article

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.



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