Arcetri Astrophysical Observatory

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logosmallarcetri Arcetri Technical Report 5/2018


Nuovo sistema di controllo assi
per il telescopio di Amici

V. Biliotti, G. Falcini, L. Carbonaro, F. Tittarelli, D. Panella, S. Di Franco, L. Cresci, S.Bianchi

INAF Osservatorio Astrofisico di Arcetri

Sommario

Questo rapporto interno descrive l’elettronica del nuovo sistema di controllo assi per Telescopio di Amici. La documentazione inizia descrivendo l’integrazione della scatola di controllo con il resto dei dispositivi presenti nella cupola, scende nel dettaglio dello schema elettrico, e arriva fino alla programmazione degli azionamenti. La documentazione si conclude con un capitolo dedicato alla risoluzione dei problemi.

The Pdf version

 

logosmallarcetri Arcetri Technical Report 4/2018


SKA Project Series
Quantization effects and nonlinearities in multi-bit correlation

S. Chiarucci, G. Comoretto

INAF Osservatorio Astrofisico di Arcetri

Abstract

An astronomic correlator analyses a signal that has a Gaussian bivariate statistics, quantized with a limited number of bits. The correlator response to the quantized signal is linear only in a limited range of the signal amplitude, but the relation between the quantized and unquantized correlation is well known, and most present day correlators correct for this effects. In large interferometers, with hundreds of antennas and thousands of spectral channels, it can be advantageous to limit the signal amplitude to the linear region, and completely avoid the quantization correction. Nonlinearities have been computed for quantization schemes from 4 to 9 bits. When 4 or 5 bits are used, keeping the signal in the linear region causes a degradation in the quantization efficiency. Autocorrelation is always affected when using quantization with less than 8 bits, and must be corrected. The effect of rounding in requantization is also considered.

The Pdf version

 

logosmallarcetri Arcetri Technical Report 2/2018


SKA Project Series
LFAA tile processing module programming manual

G. Comoretto, C.Belli

INAF Osservatorio Astrofisico di Arcetri

Abstract

The Tile Processing Module is a board performing the data acquisition, channelisation and beamforming for 16 antennas in the SKA LoW Frequency Aperture Array instrument. 16 TPMs are connected using a 40 Gb Ethernet network, to compose a LFAA station with 256 antennas. The LFAA signal processing firmware is composed of modular elements, which are programmed using a standard memory mapped interface. Each module is managed by a software element (plugin), written in Python, which allows a higher level software to manage the board using a standardized set of functions. Here the interface for each module, and the associated plugin, is described for all modules used in the TPM signal processing chain.

Pdf version of this report

 

logosmallarcetri Arcetri Technical Report 3/2018


SKA Project Series
Describing LFAA using SysML

C.Belli, G. Comoretto

INAF Osservatorio Astrofisico di Arcetri

Abstract

During the preparation of the documentation for the SKA Low Frequency Aperture Array, a system modelling tool has been used to aid the system design. The tool adopts the SysML graphics language to describe the system product breakdown structure, to identify the internal and external connection between its elements, the interfaces that characterise the system, and to describe the functions and the data flow associated with each element. The derived diagrams were used in the documents being prepared for the instrument critical design review.

The main advantage in applying such an approach is the ease of modification and maintenance of the documentation. As the elements composing the system and their relations are defined inside the abstract model, any change is automatically reflected in a consistent ways in all diagrams describing the instrument.

The Pdf version of this report.

 

logosmallarcetri Arcetri Technical Report 1/2018


SKA Project Series
SKA-PSS - SKA CSP Pulsar Search LMC Detailed Design Document

C.Baffa, E.Giani

INAF Osservatorio Astrofisico di Arcetri

Abstract

The purpose of this document is to describe the Detailed Design for the SKA Phase 1 CSP Pulsar Search Sub-element LMC (PSS.LMC), with a solution that applies to both SKA Phase 1 Mid (CSP_Mid) and SKA Phase 1 Low (CSP_Low). In this document we present the Arcetri contribution to the SKA CSP Pulsar Search Detailed Design Document along with some general presentation (Author A.Kastergiou and the SKA TDT Team).

The Pdf version of this report will be publicy available after SKA CDR (expected late 2018)