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1
Content available A critical analysis of IMO S-Mode Guidelines
EN
Circular on “Guidelines for the Standardization of User Interface Design for Navigation Equipment”, commonly known as “S-Mode Guidelines”, has lately been approved by International Maritime Organisation. Its potential impact on default and common user settings of radar equipment, electronic chart display & information system, and integrated navigation system has been discussed in the article. Several issues that should be considered during technical implementation of the circular provisions and follow-up familiarization of navigators with the affected equipment have been identified.
EN
The article presents analysis of the automatic radar plotting aid (ARPA) and automatic identification system (AIS) indications reliability performed on the base of the results of measurements conducted on merchant vessels at sea. In the first part of the article titled “Comparative study of the accuracy of AIS and ARPA indications. Part 1. Accuracy of the CPA indications” are described: vessels on which the tests were carried out, AIS and radar equipment installed on them, observed meeting situations and accuracy of the CPA indication. In this article are discussed, for the same meeting situations, accuracy of the information on true course and true speed of the opposite vessel presented by ARPA and AIS and correlation between this accuracies and errors of the CPA indication.
EN
The signals with ideal correlation properties are of interest for continuous wave radar. At the same time it’s important to provide low sensitivity to Doppler shifts of frequencies. There were considered signals with special structure due to amplitude modulation which provide capability of radar work with Search and Rescue Transponder (SART). Because the amplitude modulation has a drawback – not efficient use of signal energy, in a class of proposed signals there were considered signals with uniform amplitude. The mismatched filtering may be used by means special weighting functions for obtaining the necessary correlation properties.
EN
By utilizing meteorological data such as relative humidity, temperature, pressure, rain rate and precipitation duration at eight (8) stations in Aegean Archipelagos from six recent years (2007 – 2012), the effect of the weather on Electromagnetic wave propagation is studied. The EM wave propagation characteristics depend on atmospheric refractivity and consequently on Rain-Rate which vary in time and space randomly. Therefore the statistics of radio refractivity, Rain-Rate and related propagation effects are of main interest. This work investigates the maximum value of rain rate in monthly rainfall records, for a 5 min interval comparing it with different values of integration time as well as different percentages of time. The main goal is to determine the attenuation level for microwave links based on local rainfall data for various sites in Greece (L-zone), namely Aegean Archipelagos, with a view on improved accuracy as compared with more generic zone data available. A measurement of rain attenuation for a link in the S-band has been carried out and the data compared with prediction based on the standard ITU-R method.
EN
The quality of radar target tracking has a great impact on navigational safety at sea. There are many tracking filters used in maritime radars. Large group of them are multiple model filters in which differ-ent filter parameters are used for different states (models) of vessel movement. One of possible filter is multi-ple model neural filter based on General Regression Neural Network. Tuning of such filter means to adjust its parameters for a suitable target movement model. This paper shows the results of an experiment aiming at de-termining such models based on statistical analysis of target's movement parameters. The research has been carried out with PC-based simulator in which typical radar measuring errors were implemented. Different manoeuvres of targets have been examined. Based on this, the possibility of movement models description has been stated as conclusion.
PL
W artykule przedstawiono problemy związane z wyborem miejsc lokalizacji urządzeń radarowych na przykładzie analizy warunków pracy stacjonarnego radaru meteorologicznego. Artykuł zawiera omówienie sposobu analizy właściwości pozycji przewidzianej do instalacji radaru oraz przykładową analizę warunków pracy radaru stacjonarnego, ukierunkowaną na identyfikację przeszkód terenowych powodujących przesłanianie wiązki radarowej.
EN
The article presents problems associated with the choice of locations for the radar equipment at the example of the working conditions of stationary meteorological radar. Article will discuss the way of analysis of the properties entry for the installation of radar and a sample analysis of working conditions for stationary radar, aimed at identifying obstacles causing shadowing radar beam.
PL
W artykule przedstawiono metodę określania dokładności estymacji współrzędnych obiektów powietrznych w radarze wykrywania i wskazywania celów z wykorzystaniem radiolokacyjnej stacji śledzącej oraz przykładowe wyniki badań przeprowadzonych ta metodą.
EN
A method for determination of air objects co-ordinates estimation accuracy in the surveillance radar by using a tracting radar and some test results exploiting the method are presented in the paper.
PL
W artykule omówiono zasady działania amplitudowych, fazowych i amplitudowo - fazowych monoimpulsowych systemów radiolokacyjnych. Przedstawiono podstawowe zależności teoretyczne i schematy funkcjonalne odpowiednich dyskryminatorów na podstawie których wyznaczono charakterystyki pelengacyjne omawianych systemów. Przedstawiono również przykłady rozwiązań urządzeń radiolokacyjnych wykorzystywanych do jednoczesnego wyznaczania współrzędnych kątowych wykrywanego obiektu, określonych w dwóch wzajemnie prostopadłych płaszczyznach.
EN
The paper presents fundamental concepts of amplitude - comparison and phase - comparison methods applied for measuring the direction (precisely its angular coordinates) of arrival of the electromagtnetic radiation. The radiation may emanate from an active source or from a passive object that reradiates some of the electromagnetic wave incident on it. It is described how the signals simultaneously received by two or four independent antenna channels are processed in order to obtain the appropriate responses. These responses are univocally related to the azimuth and elevation coordinates being evaluated. The functional block diagrams of the corresponding signal processors are also discussed.
PL
W artykule omówiono zagrożenia ekologiczne związane z promieniowaniem mikrofalowym o dużej gęstości emitowanym przez urządzenia radiolokacyjne. Podjęto problem negatywnego oddziaływania promieniowania mikrofalowego na organizmy żywe. Scharakteryzowano przedsięwzięcia organizacyjne oraz środki techniczne ograniczające skutki wpływu promieniowania na organizm człowieka
EN
In this paper the ecological dangers of microwave emission high-density energy emitted by radiolocation equipment have been discussed. The problem of negative influence on live organisms of microwave emission have been described. The organisation enterprises and technical equipments discriminating the results of influence of very high frequency emission on human organism have been charakterised
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