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Report on the adjustment of the United European Levelling Net and related computations

PoG 2, J.E. Alberda, Report on the adjustment of the United European Levelling Net and related computations

J.E. Alberda

Publications on Geodesy 6 (Vol. 1 Nr. 2). Delft, 1963. 49 pagina's.
ISBN-13: 978 90 6132 202 3. ISBN-10: 90 6132 202 2.


In 1955, at the Florence meeting of the Permanent International Commission on European Levellings, it was agreed among other things that the Computing Centre of the Delft Technological University would undertake to compute the adjustment of the United European Levelling Net by a method based on principles indicated by the late professor J. M. Tienstra. It was decided from the start that the Delft adjustment would be an adjustment by steps (or, in Tienstra's terminology an adjustment in phases).

Some small test-computations were made in 1956 to see what would be the most suitable set-up of the adjustment. The data for the adjustment were received from the Commission's President, Dr. 0. Simonsen, in May 1958.

The organization of the actual computations started in October 1958. The adjusted geo-potential numbers of bench marks were presented at the meeting of representatives of computing centres which was held at Delft in January 1959. Part of the weight coefficients of these geo-potential numbers were also ready by then; the rest of the weight coefficients followed soon.

The geo-potential numbers of mean sea level, as resulting from the net, were received at the end of August, 1959 from Dr. Simonsen. A statistical investigation of these values was carried out in September 1959 and a provisional report on the adjustment and connected investigations was presented to the Liverpool Symposium in October 1959; an outline of this report is published in [l]. Finally, some checks and re-computations were made in 1960. The re-computations were necessitated by the discovery of a gross error in the line 218 ->J-D-F-2. All results in this report are based on the corrected data.


  1. 1. Introduction  1
  2. The adjustment  2
  3. The precision and accuracy  12
  4. The geo-potential of mean sea level  26
  5. Computational aspects  38
  6. Final Remarks  39

References  41
Tables  42

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