عنوان مقاله [English]
نویسنده [English]چکیده [English]
In this paper, the observational data provided by two types of GPS operations conducted in July 1991 in the areas of Pohjanmaa and Savo-Kainuu in the country of Finland have been investigated. In this test, the Bernese software system was used to process the data. Although some of the GPS data mentioned above have been affected by rapid changes in the ionospheric refraction, when particular care is taken with regard to data processing, the concurrent solutions of GPS observational sessions seem to be still useful. On the other hand, the orbital path of each satellite is divided into two circuits, one four-day circuit and the other a three-day circuit. All the satellite orbital paths are corrected and improved in the final mathematical solution by estimating all possible parameters. The magnitude of changes at particular intervals for occupied open- lengths can be achieved by comparing the lengths obtained by the GPS-method with open-lengths derived
from classical first-order triangulation.
The results from the Savo-Kainuu region are well matched with the results of combining triangulation networks and even with classical first-order triangulation network. Finally, the results obtained from the Pohjanmaa area are very weak and do not match the results of geodetic (classical) observations.