Krzysztof Bikonis

Geographical Information System for analysis of Critical Infrastructures and their hazards due to terrorism, man-originated catastrophes and natural disasters for the city of Gdansk

The paper presents a web-based Geographic Information System (GIS) for assessment and visualization of Critical Infra structure (CI) and its hazards which was developed by the Department of Geoinformatics at Gdansk University of Technology for the City of Gdansk. The system allows spatial processing and mapping of various CI analysis results, with the CI analysis module based on the CARVER2™ technology adapted to particular requirements of the Gdansk City Hall Crisis Management Department (CMD). The system works as an integrated solution for both visualization of hazard scenarios and a team-enabled environment for information analysis and sharing among geographically distributed decision makers. The paper focuses on the sample applications with reference to the analysis, visualization, and mapping in a geographical context of several threat scenarios, such as blast attack, chemical attack, and toxic leakage as well as the spatial distribution of critical infrastructure components in Gdansk, Poland.

Computer Vision Techniques Applied for Reconstruction of Seafloor 3D Images from Side Scan and Synthetic Aperture Sonars Data

The Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled images. The paper presents the concept of processing the Side Scan Sonar and Synthetic Aperture Sonar records for detailed reconstruction of 3D seafloor using Shape from Shading techniques. Shape from Shading is one of the basic techniques used in computer vision for the objects reconstruction. The algorithms proposed in the paper use the assumed Lambert model of backscattering strength dependence on incident angle and utilize additionally the information from shadow areas for solving obtained set of equations. The idea was verified by simulation study. The obtained results ...

Application of Shape From Shading Technique for Side Scan Sonar Images

Abstract Digital signal processing technology has revolutionized a way of processing, visualisation and interpretation of data acquired by underwater systems. Through many years side scan sonars were one of the most widely used imaging systems in the underwater environment. Although they are relatively cheap and easy to deploy, more powerful sensors like multibeam echo sounders and sonars are widely used today and deliver 3D bathymetry of sea bottom terrain. Side scan sonar outputs data usually in a form of grey level 2D acoustic images but the analysis of such pictures performed by human eye allows creating semi-spatial impressions of seafloor relief and morphology. Hence the idea of post-processing the side scan sonar data in a manner similar to human eye to obtain 3D visualisation. In recently developing computer vision systems the shape from shading approach is well recognized technique. Applying it to side scan sonar data is challenging idea used by several authors. In the paper, some further extensions are presented. They rely on processing the backscattering information of each footprint (pixel in sonar image) along with its surroundings. Additionally, a current altitude is estimated from the size of shadow areas. Both techniques allow constructing 3D representation of sea bottom relief or other investigated underwater objects.

Nearly real-time, safety-related, remotely accessible marine GIS

The paper presents the prototype of safety-related application of the newly developed real-time, remotely accessible marine GIS for water pollution monitoring and emergency management supporting. The system is able to integrate many different types of marine pollution survey data, including those acquired by acoustic sensors. It processes the data extracted from acoustic echo signals and supports the instantaneous 2/sup D/ and 3/sup D/ visualisation and mapping of pollution aggregations (oil spills, discharge material plumes etc.). It also deals with the multi aspect data management and data analysis, and the prediction of the pollutants behaviour. The system makes use of the SQL database standard for data storage and the Scalable Vector Graphics (SVG) and Virtual Reality Modelling Language (VRML) for geographical objects remote presentation. Moreover, it requires only the WWW browser with SVG and VRML plug-in on the client side.

Data Integration from GPS and Inertial Navigation Systems for Pedestrians in Urban Area

The GPS system is widely used in navigation and the GPS receiver can offer long-term stable absolute positioning information. The overall system performance depends largely on the signal environments. The position obtained from GPS is often degraded due to obstruction and multipath effect caused by buildings, city infrastructure and vegetation, whereas, the current performance achieved by inertial navigation systems (INS) is still relatively poor due to the large inertial sensor errors. The complementary features of GPS and INS are the main reasons why integrated GPS/INS systems are becoming increasingly popular. GPS/INS systems offer a high data rate, high accuracy position and orientation that can work in all environments, particularly those where satellite availability is restricted. In the paper integration algorithm of GPS and INS systems data for pedestrians in urban area is presented. For data integration an Extended Kalman Filter (EKF) algorithm is proposed. Complementary characteristics of GPS and INS with EKF can overcome the problem of huge INS drifts, GPS outages, dense multipath effect and other individual problems associated with these sensors.

Design of the dual constellation GPS/GALILEO mobile device for improving navigation of the visually impaired in an urban area

Abstract The article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of advanced computer technology. It is demonstrated that one of causes of the damages is the lack of research activities oriented on recognising random properties of the loads leading to those damages. A proposal is made for the loads acting at a given time t on tribological associations in crankshaft and piston systems of internal combustion engines used as main engines to be considered as random variables Qt. At the same time the loads examined within a given time interval tr ≤ t ≤ tz would be considered stochastic processes {Q(t): t ≥ 0}. Essential properties of the loads of the abovementioned tribological associations are named and explained by formulating hypotheses which need empirical verification. Interval estimation is proposed for estimating the expected value E(Qt) of the load Qt acting at time t. A relation is indicated between the mechanical load and the thermal load acting on tribological associations in the ship main engine crankshaft and piston system. A suggestion is formulated that a stochastic form of the relation between these types of load is to be searched for, rather than statistic relation, and a proposal is made to measure the intensity (strength) of the stochastic relation using the Czuprow’s convergence coefficient.

3D visualization of marine organism distribution and movement in water column using virtual reality techniques

Virtual reality techniques mainly developed for computer graphics had found numerous applications in various scientific areas like chemistry, astronomy, geography, etc. The paper proposes application of the virtual reality techniques in hydroacoustics for 3D visualization of data acquired by split‐beam or multi‐beam echosounders. Both types of echosounders allow for nonambiguous localization of targets in the water column and their imaging. As the multi‐beam systems also delivers bathymetric information, in addition to imaging of the spatial distribution, it is possible to create complete virtual scene of sampled volume. Using builtin properties of Virtual Reality Modeling Language (VRML) it was possible to animate movement of fishes and other marine organisms in the water column. As the language is supported by Internet technology, its textlike description allows for easy rendering by most popular WWW browsers.

Geocorrection and filtering of 3D bottom images from multi‐beam sonar records

For the last decade multibeam sonars have been increasingly used for mapping and visualization of the seafloor to provide the ‘‘physical bases’’ for environmental studies. Increasing amount of digital (raster) echo records of high resolution from a multibeam sonar have enhanced the potential of computer modeling of the marine environment to improve our understanding of the bottom processes. However, the 3D bottom images as the result of merging different sonar transects do not comply exact geographical positions and should be corrected. Additionally, the raw sonar records are subject to systematic errors, random noise and outliers. In this paper, Kalman filtering techinque to generating optimal estimates of bottom surface from a noisy raw sonar records is proposed. The experiment on the surface indicates that after applying the Kalman filtering the outliers of raw records can be efficiently removed. Moreover, the two‐step Kalman filtering method enables 3D seabed visualization in real time. The paper prop...