Models for Source Structure Corrections

Abstract

At the milli-arcsecond scale, most of the extra-galactic radio sources exhibit spatially-extended intrinsic structures which are variable in both time and frequency. Such radio structures set limits on the accuracy of source positions determined with the Very Long Baseline Interferometry (VLBI) technique unless their effects in the astrometric data can be accounted for. We review the modeling scheme for calculating source structure corrections and discuss the magnitude and impact of these effects for the sources that are part of the International Celestial Reference Frame (ICRF). Results obtained by applying source structure corrections to actual VLBI observations on the time-varying source 4C39.25 (0923 + 392) are also presented.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2000
Accession Number
ADA435491

Entities

People

  • P. Charlot

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Accuracy
  • Band Structures
  • Brightness
  • Databases
  • Emission
  • Energy Bands
  • Frequency
  • Frequency Bands
  • Geodesics
  • Gray Scale
  • Jet Propulsion
  • Observation
  • Observatories
  • Uncertainty
  • X Band

Fields of Study

  • Physics

Readers

  • Astronomy and Astrophysics.
  • Computational Modeling and Simulation