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Báo cáo hóa học: " DSP-Enabled Radio Astronomy: Towards IIIZW35 Reconquest"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: DSP-Enabled Radio Astronomy: Towards IIIZW35 Reconquest | EURASIP Journal on Applied Signal Processing 2005 16 2686-2693 2005 Hindawi Publishing Corporation DSP-Enabled Radio Astronomy Towards IIIZW35 Reconquest Rodolphe Weber Laboratoire d Electronique Signaux Images Polytech Orleans Universite d Orleans 12 rue de Blois BP 6744 45067 Orleans Cedex 2 France Email rodolphe.weber@univ-orleans.fr Cedric Viou Station de Radioastronomie de Nancay Observatoire de Paris CNRS No. 704 18330 Nancay France Em ail cerdric.dumez-viou@obs-nancay.fr Andree Coffre Station de Radioastronomie de Nancay Observatoire de Paris CNRS No. 704 18330 Nancay France Email andree.coffre@obs-nancay.fr Laurent Denis Station de Radioastronomie de Nancay Observatoire de Paris CNRS No. 704 18330 Nancay France Email laurent.denis@obs-nancay.fr Philippe Zarka LESIA Observatoire de Paris CNRS 5 Place Jules Janssen 92195 Meudon France Email philippe.zarka@obspm.fr Alain Lecacheux LESIA Observatoire de Paris CNRS 5 Place Jules Janssen 92195 Meudon France Email alain.lecacheux@obspm.fr Received 31 January 2004 Revised 24 February 2005 In radio astronomy the radio spectrum is used to detect weak emission from celestial sources. By spectral averaging observation noise is reduced and weak sources can be detected. However more and more observations are polluted by man-made radio frequency interferences RFI . The impact of these RFIs on power spectral measurement ranges from total saturation to subtle distortions of the data. To some extent elimination of artefacts can be achieved by blanking polluted channels in real time. With this aim in view a complete real-time digital system has been implemented on a set of FPGA and DSP. The current functionalities of the digital system have high dynamic range of 70 dB bandwidth selection facilities ranging from 875 kHz to 14 MHz high spectral resolution through a polyphase filter bank with up to 8192 channels with 49 152 coefficients and real-time time-frequency blanking with a robust threshold detector. This receiver has .