Jacek Stefanski

The State of the Art in the Field of Non-Stationary Instruments for the Determination and Monitoring of Atmospheric Pollutants

The growing interest in obtaining rapid and more reliable data on air quality indicates a need for non-stationary (transportable and portable) instrumentation. This trend results in the designing and manufacturing of new instruments that are more sensitive, selective, precise and accurate. This paper presents some examples of new instrumentation based on different principles. In the first part, a general classification of devices used for air monitoring and analysis is presented. Finally, the mobile monitoring system (MMS) proposed by the authors for air monitoring along communication lanes is briefly described.

Bad Geometry Influence on Positioning Accuracy in Wireless Networks

The aim of this paper is to discuss a connection between the geometric configuration and positioning accuracy in wireless networks exploiting the TDOA technique. At the beginning, a simulation model of TDOA localization technique is described. We use the Taylor series expansion and least square fit method to estimate the terminals position. In this part we also derive a statistical model for calculating the geometric dilution of precision (GDOP), which is here a variable reflecting geometric quality with respect to the hyperbolic lateration. The two dimensional root mean square (RMS) error metric is also presented in order to make necessary accuracy calculations. We then describe an impact of the bad configuration of measurement units on the positioning accuracy. Basing on simulation results, the TDOA efficiency for different time errors and geometric circumstances is presented. Finally, we show an empirical solution for decreasing the bad geometry effect. The accuracy is improved thanks to the additional measurement units placed in the good geometry conditions.

Mobile system for on-road measurements of air pollutants

The paper presents a prototype of a mobile monitoring system for measuring the levels of the main traffic air pollutants (C(6)H(6), NO(2), NO(x), CO, and CO(2),) in cities. The novelty of the proposed system lies in the fact that it can be utilized to monitor emissions from urban traffic along roads and areas where traditional monitoring stations cannot be placed. In the proposed system, the monitoring device can be mounted on any moving vehicle (such as a car, bus, or truck) rather than be attached to a dedicated van, as most systems of this kind found in literature are. Analyzers used in this system are small portable structures that contain an electronic instrument to measure, record, and transmit relevant data on concentrations of the pollutants to a website. The model outcome for carbon monoxide obtained in functional tests in real conditions is also presented here. Data on temporal changes of carbon monoxide concentration are compared against meteorological parameters and speed of the vehicle. Spatial interpolation techniques are applied to obtain a nonplanar visualization of carbon monoxide and benzene concentrations in the main arteries of a city.

Self-organizing wireless monitoring system for cargo containers

Self-organizing wireless monitoring system for cargo containers This paper presents a description of new global monitoring system for containers with its layer-modular structure, as a solution for enhance security and efficiency of container transport with particular emphasis on the practical implementation of that system for maritime container terminals. Especially the Smart Container Module (SCM) architecture and its operation as a part of the Self-Organizing Container Monitoring Network is presented.

Method of Location of a Mobile Station in the WCDMA System without Knowledge of Relative Time Differences

The concept of a new and low cost method for a location service (LCS) in the wideband code division multiple access (WCDMA) is outlined. This method enables the calculation of the geographical position of a mobile station (MS) without knowledge of relative time differences (RTDs). An elimination process of RTDs is based on idle period downlink (IPDL) mode.

Simplified algorithm for location service for the UMTS

The concept of a simplified algorithm for a Location Service (LCS) in the Universal Mobile Telecommunication System (UMTS) is outlined. This algorithm enables the calculation of the geographical position of a mobile station (MS) without knowledge of relative time differences (RTDs). The simulation results of the proposed method are presented. These results show that in the studied environment, the proposed algorithms fulfil the US E911 phase II requirements of positioned emergency calls within 125m in 67% of the time.

Asynchronous time difference of arrival (ATDOA) method

A new method for a location service in the asynchronous wireless sensor networks is outlined. This method, which is called asynchronous time difference of arrival (ATDOA), enables calculation of the position of a mobile node without knowledge of relative time differences (RTDs) between measuring sensors. The ATDOA method is based on the measurement of time difference of arrival between the node and the same sensor at the discrete time n and n + 1 , and the solution of a nonlinear system of equations. The paper concentrates on the description of the method, solving the nonlinear system of equations and simulation results.

Research study on reception of GNSS signals in presence of intentional interference

The article focuses on performance of Global Navigation Satellite System (GNSS) receivers in environment where intentional interference is present. First part is a general description of the GNSS systems. Secondly, types of positioning service disturbances are specified. Next, a scheme of measurement setup, which is used to evaluate the influence of interference disturbances on reception of navigation signals, is presented. Subsequently, research methodology with obtained results have been described. Finally, summarized conclusion has been done.

Hyperbolic Position Location Estimation in the Multipath Propagation Environment

The efficiency analysis a hyperbolic position location estimation in the multipath propagation environment in the wideband code division multiple access (WCDMA) interface was presented. Four, the most popular methods: Chan’s [1], Foy’s [2], Fang’s [3] and Friedlander’s [4] were considered. These algorithms enable the calculation of the geographical position of a mobile station (MS) using the time differences of arrival (TDOA) between several base stations (BS) and MS. The simulation model is outlined and simulation results are presented.

Asynchronous and self-organizing radiolocation system — AEGIR

Since first travels by land or sea, it was necessary to determine position in an unknown environment. At the beginning methods were simple. They were based on the observation of characteristic points, in the case of shipping additional observations of the coastline. Then came a navigation based on astronomical methods (astronavigation). At the beginning of the XX-century a new way of determining the current location was developed. It uses radiowave signals. First came the radio-beacons, which at fixed intervals, transmitted well-defined sequence of radio signals. Then came ground-based systems. Pulse signals are received from at least three stations operating synchronously. Electronically measured the delay of one signal relative to the other, allows to determine the difference in distance separating the object from the localized sources. According to the principles of geometry allows the plot (or find) on the map hyperbole, which is the object. The newest way to determine your position are satellite systems. They are based on the measurement of arrival time of radio signals from satellites to the receiver. Currently, the most popular system is GPS (Global Positioning System). This system is fully controlled by the Department of Defense, and only the U.S. forces and their closest allies have guaranteed accuracy offered by the system. Armies of other countries can only use the civilian version. Due to the popularity of this system and its worldwide range, terrorist can build bombs with simple GPS receivers to detonate in a specific place. To prevent this, deliberate errors to the civilian version of the system can be introduced. Those deliberate errors will also prevent the use of GPS by the secret services or the armies of other countries than the U.S. This situation has spawned the need for an independent radiolocation system. This article describes the construction and operation of such a technology demonstrator that was developed at the Technical University of Gdansk. It was named AEGIR (according to Norse mythology: god of the seas and oceans). The main advantage of the system is to dispense with the chain organization of the reference station, which work with each other asynchronously. This paper presents results and analysis of its effectiveness.