1,298 research outputs found
Multi-Level Pre-Correlation RFI Flagging for Real-Time Implementation on UniBoard
Because of the denser active use of the spectrum, and because of radio
telescopes higher sensitivity, radio frequency interference (RFI) mitigation
has become a sensitive topic for current and future radio telescope designs.
Even if quite sophisticated approaches have been proposed in the recent years,
the majority of RFI mitigation operational procedures are based on
post-correlation corrupted data flagging. Moreover, given the huge amount of
data delivered by current and next generation radio telescopes, all these RFI
detection procedures have to be at least automatic and, if possible, real-time.
In this paper, the implementation of a real-time pre-correlation RFI
detection and flagging procedure into generic high-performance computing
platforms based on Field Programmable Gate Arrays (FPGA) is described,
simulated and tested. One of these boards, UniBoard, developed under a Joint
Research Activity in the RadioNet FP7 European programme is based on eight
FPGAs interconnected by a high speed transceiver mesh. It provides up to ~4
TMACs with Altera Stratix IV FPGA and 160 Gbps data rate for the input data
stream.
Considering the high in-out data rate in the pre-correlation stages, only
real-time and go-through detectors (i.e. no iterative processing) can be
implemented. In this paper, a real-time and adaptive detection scheme is
described.
An ongoing case study has been set up with the Electronic Multi-Beam Radio
Astronomy Concept (EMBRACE) radio telescope facility at Nan\c{c}ay Observatory.
The objective is to evaluate the performances of this concept in term of
hardware complexity, detection efficiency and additional RFI metadata rate
cost. The UniBoard implementation scheme is described.Comment: 16 pages, 13 figure
Lieux, images, événements dans l'écriture poétique: Jacint Verdaguer
This contribution begins with a reflection on LÂ’AtlĂ ntida. It so happens that this
work enables us to understand what, it has been proposed in recent years, should be
called the “syntax of imagination”, that is to say, the process by which the creator of a
poem reinforces the impact of his discourse by setting up in the background a sort of
supraverbal continuum. This unreal element can be the very basis of the isotopy of the
discourse: the author of the article called it “the persistent murmur of a lost world”.
For Canigó, the place occupied by the Occitan region was evoked – Provence in
particular, but also Mare Nostrum – while L’Atlà ntida gave readers the opportunity to
recall the pan-Iberian and Mediterranean projection of the poetÂ’s purpose: the two works,
each in their own way, open the door to the universal
El pensamiento de Milton Friedman en el marco de la escuela de Chicago
El pensamiento de Milton Friedman en el marco de la escuela de Chicag
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