|
The main aspect of the study was to evaluate the use of GNSS technology for measurement possibilities and obtaining the required position accuracy of objects in a forest area: point (eg. the location of tree trunks, landmarks), linear (eg. roads, paths) and surface (eg. the area of various plant types). The objects position with different measurement modes and various GPS receivers was done, starting from receivers for tourists, cartographs and modern multifrequency and multichannel (NAVSTAR-GPS+ GLONASS) GNSS receivers designed to work with network of reference stations. The measurements were assessed measuring the required number of sessions conducted in different measurement modes, to obtain an accurate position (defined by Forest Management Guide) of objects in the forest. Test sessions were analyzed in 100, 300, 600 seconds or even hours. Tests performed on different days, months, in different weather conditions, in the open area and under canopy, and for different phenological phases of vegetation (trees with leave sand without leaves). Evaluation of DGPS position determination was carried out in relation to the results obtained from RTK measurements (lots of hours of observation in the open area), measurements of total station and terrestrial laser scanning (precisely determined positions of tree trunks and course of the drainage ditch)
|