Marcas Históricas no Nacionalismo Português

The text comments the presence of historical tensions in the Portuguese literature, thus giving special attention to the nationalist aspects of the thematic in that tradition. The analytic way implies the comparison of representative works in the Portuguese literary tradition faced with thematic endurance and possible reflexes of the literary tradition in Portugal in the interface with historical values. The analytical focus values the presence of ways which are well-trodden by the nationalism in different literary works, giving focus, when possible, in the relationship between literature and History.O texto comenta a presença de tensões históricas na literatura portuguesa, dando especial atenção aos aspectos da temática nacionalista nessa tradição. O caminho analítico implica o cotejo de obras representativas dentro da tradição literária portuguesa face à ideia de permanência temática e de possíveis reflexos da tradição literária em Portugal na interface com valores históricos. O foco analítico valoriza a presença de caminhos trilhados pelo nacionalismo em diferentes obras literárias, dando enfoque, quando possível, na relação entre literatura e História

Error Estimation in Target Height Finding Using VHF Radars and a Three-Antenna System Positioned one Above the Other in a Radar Network

Abstract: A combined algorithm for automatic target detection and height estimation, based on amplitude comparison using multipath lobes of three sensors positioned one above the other, and a three-positioned in a plane method, is proposed in this paper. A method for three-positioned radar system base estimation, allowing target height measurement with height probability of detection, is developed and applied. The measurement accuracies, achieved with two approaches for target height estimation with identical statistical and power detection parameters, are compared. The suggested approach can be successfully applied in different sensor system solutions

Time of arrival estimation in pulsar-based navigation systems

This paper focuses on the Time of Arrival (TOA) estimation problem related to new application of pulsar signals for airplane-based navigation. The aim of the paper is to propose and evaluate a possible algorithm for TOA estimation that consists of epoch folding, filtering, CFAR detection, crosscorrelation and TOA calculation. The TOA estimation algorithm proposed is verified using real experimental data obtained from the Westerbork radio observatory in The Netherlands. The performance of the proposed TOA algorithm is evaluated in terms of SNR at the cross-correlator input and the TOA accuracy

Detection and estimation of pulsar signals for navigation

The paper focuses on scientific issues related to new application of pulsar signals for airplane-based navigation. A possible algorithm for processing of pulsar signals that consists of epoch-folding, matched filtering and detection is proposed and evaluated in this paper. The algorithm proposed is verified using the real experimental data obtained from the radio observatory Dwingeloo, the Netherland. The serious trouble in this study is that the total number of the input data within a repetition period is much more of the number of samples in a pulsar template taken from the EPN database. Therefore have been developed and evaluated two new algorithms for epoch-folding, which not only improve Signal-to-Noise Ratio of pulsar signals but as well reduce the number of samples of the output signals to the required number