Measured Physical and Optical Properties of the Passive Geodetic Satellite (Pageos) and Echo 1

  1. Soren W. Henriksen,
  2. Armando Mancini and
  3. Bernard H. Chovitz
  1. David S. Mcdougal1,
  2. Robert Benjamin Lee III1 and
  3. Daryl C. Romick2

Published Online: 15 MAR 2013

DOI: 10.1029/GM015p0253

The Use of Artificial Satellites for Geodesy

The Use of Artificial Satellites for Geodesy

How to Cite

Mcdougal, D. S., Lee, R. B. and Romick, D. C. (1972) Measured Physical and Optical Properties of the Passive Geodetic Satellite (Pageos) and Echo 1, in The Use of Artificial Satellites for Geodesy (eds S. W. Henriksen, A. Mancini and B. H. Chovitz), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM015p0253

Author Information

  1. 1

    NASA Langley Research Center, Hampton, Virginia 23365

  2. 2

    Goodyear Aerospace Corporation, Akron, Ohio 44306

Publication History

  1. Published Online: 15 MAR 2013
  2. Published Print: 1 JAN 1972

ISBN Information

Print ISBN: 9780875900155

Online ISBN: 9781118663646

SEARCH

Keywords:

  • National Geodetic Satellites Program;
  • Probable error;
  • Radius of curvature;
  • Satellite photometry;
  • Total reflectance

Summary

Two satellites used for geodesy, Pageos and Echo 1, have been observed in a continuing program since 1966 to determine the stability of their physical and optical properties. Measurements are made in the UBVRI spectral system. The amount of solar radiation reflected from a satellite's surface is measured photoelectrically and is calibrated against known stellar magnitudes by standard astronomical techniques. The calibrated satellite magnitudes are analyzed with respect to the sun-satellite-observer phase angle to infer the shape and size of the satellite and the reflective properties of the satellite's surface material. The physical and optical properties are used to determine proper position of the solar image on the satellite's surface, resulting in more precise geometric geodesy. Quantitative results from five observing periods indicate that, although local structural anomalies appear to exist, both satellites essentially maintained their nominal average 30.48-meter (50-foot) radius of curvature and specular reflecting characteristics.