Publications on Geodesy 14 (Vol. 4 Nr. 1). Delft, 1971. 30 pagina's.
ISBN-13: 978 90 6132 214 6. ISBN-10: 90 6132 214 6.
In the summer of 1968 astronomical observations were carried out at the primary stations Ubachsberg (The Netherlands) and Tongeren (Belgium) in order to make a twin Laplace point of these two stations. This work was undertaken in behalf of the New Adjustment of the European Triangulation. The latitude, longitude, and azimuth were determined simultaneously applying Blacks method and using a Wild T4 universal theodolite. The results obtained are shown in section 8.
The main purpose of the measurements was to determine the geodetic azimuth Ag = A + (l - l)sin j0 , which was obtained with high accuracy, because of the strong negative correlation between the astronomical azimuth and astronomical longitude.
The misclosure between the two stations of this twin Laplace point amounts to 0''.57.
Furthermore, the accuracy requirements for Laplace points in The Netherlands were investigated.
Based on the deviation of the geodetic part of the Laplace equation, it was found that a standard deviation of 0".25 in the geodetic azimuth suffices.
The observer's personal equation was determined using an artificial moving star.
List of symbols and constants 4
- Introduction 5
- The Black method 6
- Selection of stars 9
- Instruments 10
- Testing of the equipment 12
- Instrument set-up at Ubachsberg and Tongeren 12
- Measuring programme 14
- Results 16
- Reduction to centre 17
- Computation of the misclosure 18
- Standard deviation of the observations 18
- Standard deviation of the geodetic part of the Laplace equation 21
- Personal equation of the observer 22