Geos 1 Secor Observations in the Pacific (Solution Sp 7)

  1. Soren W. Henriksen,
  2. Armando Mancini and
  3. Bernard H. Chovitz
  1. Ivan I. Mueller,
  2. James P. Reilly,
  3. Charles R. Schwarz and
  4. Georges Blaha

Published Online: 15 MAR 2013

DOI: 10.1029/GM015p0059

The Use of Artificial Satellites for Geodesy

The Use of Artificial Satellites for Geodesy

How to Cite

Mueller, I. I., Reilly, J. P., Schwarz, C. R. and Blaha, G. (1972) Geos 1 Secor Observations in the Pacific (Solution Sp 7), 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/GM015p0059

Author Information

  1. Department of Geodetic Science, Ohio State University, Columbus, Ohio 43210

Publication History

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

ISBN Information

Print ISBN: 9780875900155

Online ISBN: 9781118663646



  • Baker-Nunn station;
  • Covariance matrices;
  • Geometric satellite network;
  • National Space Science Data Center;
  • Secor observations


Secor observations carried out by the U.S. Army Corps of Engineers define a geodetic network extending through the Pacific Ocean from Japan, with three stations on the Japanese datum, to the west coast of the United States. Thus this network was connected to major datums on both ends. However, observations on Geos 1 were taken only in the middle of the network, from Truk Island to Maui, so that the network determined by Geos 1 observations alone is not directly attached to any major geodetic datum. The adjustment of this isolated network and its indirect connection to the North American datum presented several interesting problems. A little-known procedure called ‘inner adjustment’ was found to be the appropriate method to define a coordinate system for the adjustment of the isolated network and to determine the inner consistency of the observations. The network was indirectly tied to the North American datum by the use of (1) satellite observing stations of other observing systems whose coordinates were previously determined, (2) relative positions of these and nearby Secor stations, as determined by local surveys, and (3) geodetic heights composed of leveled (orthometric) heights plus geoid heights obtained from a geoid map.