OTKA: T 037384

Institution: University of West Hungary, Department of Surveying and Remote Sensing

Project title: Investigation of the high precision GPS applications on the territories of different forest cover

Project duration: 1st of January, 2002 – 31st of December, 2005.

The GPS measurements accuracy is uncertain on forested area because of the horizon and lookout limitations, both on national and international level. There is a chance of successful accurate GPS survey under forest canopy on the basis of few preliminary measurements.

The navigation uses are preferred in the forestry applications of the GPS, because of the accuracy demand, the density of the canopy, the seasonal change of the canopy and higher relief. The geodetic applications are forborne in forested area.

The forest utilisation, the opening-up and the photogrammetric activities according to the sylviculture and preservation of natural resources require geodetic accuracy on areas with higher density forest canopy. We investigate the influences of the crown closure, tree height and density, species and of other biological parameters to the accuracy achieved by different GPS receiver and processing techniques (such as static, fast-static, semi-kinematic) in our research. The forest crown closure is estimated on the basis of fish-eye zenith images. We have established a test network with the assistance of the Educational Forest Management Company of Sopron (TAEG), which is suitable for the investigation of the different Hungarian forest cover types.

The theoretic and practical expectations of the research is a technical documentation, summarising the criteria of the national forestry GPS applications, such as the optimal spot selection, the preliminary survey-planning, the right season-selection, the suggested survey-period, the method of the data-processing and the reliability to be expected.

Dr. László Bácsatyai project manager