radiotelescope

On Dr Darren's involvement with the MOST radiotelescope

Keywords:
The content or the technology discussed here is HISTORICAL or ARCHIVAL

In 1988 I was an honours physics student at the Department of Astrophysics, School of Physics, University of Sydney. Back then - with the help of many members of that department - I modelled the MOST signal-processing system in simple fashion in the FORTRAN scientific programming language (as was then still often used, these days I would of course use symbolic algebra):

An analysis of image formation by MOST (Molonglo Observatory Synthesis radioTelescope)

I also had the wonderful opportunity of helping to re-paint the telescope as a student holiday job, and thus got to know it quite well !

In 2003/04 as a Scientific IT Consultant and UML+Java developer (radioastronomy), I developed a database-driven component-tracking and modelling system for the mechanical layer of the MOST under model-driven development with Unified Modeling Language™ (UML™), using Java™ technologies such as Java Data Objects (JDO), Java3D, JavaServer Pages (JSP) and MySQL as the database.

In 2005 - with the arrival of port-based engineering notation for UML2 - I performed an educational UML™ Parsing Analysis of my honours thesis from 1988, binding text descriptions "parsed" into UML Comment elements to UML Class, Component and Association model elements, using both "associative" class diagram notation and "structural" systems engineering notations:

Gallery: a UML Parsing Analysis of an analysis of image formation in the MOST radiotelescope (from 2005)

This Webel MOST zone is dedicated to the late Dr Michael Large, whose scientific, educational, and personal skills are sorely missed. They don't build 'em like that anymore. He explained the principle of rotational synthesis to me when I was a physics student, and it was while he was explaining it to me that he had the insight into the wide-field techniques now used in MOST. That in turn taught me that to understand things one does well to teach them to others.

MOST: UML: top-level

MOST: UML: top-level
The top-level: radio waves from a distant astrophysical source are incident on the parabolic trough of each of two arms of the Molonglo Observatory Synthesis radioTelescope (MOST).

The structure of composite parts is now given in UML2.0 Composite Structure Diagrams. Also, below the components structure, the related classes that compose the port classes are given. These are consistently engineered with Java component classes1.

  • 1. I hope to provide eventually the complete Java source with a JSyn audio synthesis simulation of MOST.

MOST: UML: synthesis

MOST: UML: synthesis

UML2.0 component model overview of the MOST synthesis after (Mills, 1981) and (Kelly, 1988).

Illustrates port-definitions for MOST components using UML2.0 delegation and assembly dependencies1. Components here are nested to indicate the unique usage context for each component of the instrument. Multiplicities of components are not required for this schematic illustration, multiplicities of ports are given. The sense of flow of (software) message delegation is the opposite to the radio signal processing chain.

This could now be better modelled using deeply nested part Properties with Ports in composite structure diagrams (or Systems Modeling Language™ (SysML™) internal block diagrams).
  • 1. Do NOT imitate this technique, since 2008 MagicDraw UML supports 'delegation' and 'assembly' kind connectors properly
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