Application of 3D data derived from images captured using unmanned aerial vehicles (UAVs) in forest biomass estimation has shown great potential in reducing costs and improving the estimates. However, such data have never been tested in miombo woodlands. UAV-based biomass estimation relies on the availability of reliable digital terrain models (DTMs). The main objective of this study was to eva...

Calculation of the viewshed from a digital elevation model (OEM) is a common capability of a GIS packages. Two mistaken assumptions are made, however: first, that the OEM is accurate, and second that the viewshed is a Boolean phenomenon. The inaccuracy of the OEM data is acknowledged in reporting of the root-mean-squared error. The mistake of the Boolean viewshed is recognizable in the real-wor...

Terrestrial laser scanning is of increasing importance for surveying and hazard assessments. Digital terrain models are generated using the resultant data to analyze surface processes. In order to determine the terrain surface as precisely as possible, it is often necessary to filter out points that do not represent the terrain surface. Examples are vegetation, vehicles, and animals. Filtering ...

Up-to-date and accurate digital elevation models (DEMs) are essential for many applications such as numerical modeling of mass movements or mapping of terrain changes. Today the Federal Department of Topography, swisstopo, provides Digital Terrain Models (DTMs) and Digital Surface Models (DSMs) derived from airborne LiDAR data with a high spatial resolution of 2 m covering the entire area of Sw...

Accurate data about the forest are needed both in climate research and forest management planning. This thesis focuses on using different types of three-dimensional (3D) satellite data sources to accurately estimate forest variables, primarily aboveground biomass (AGB) and tree height (H). Different satellite sensors have been used and compared, and depending on the sensors, the acquired satell...

McClure, A.; Liu, X.-H.; Hines, E., and Ferner, M.C., 0000. Evaluation of error reduction techniques on a LIDAR-derived salt marsh digital elevation model. Journal of Coastal Research, 00(0), 000–000. Coconut Creek (Florida), ISSN 07490208. Accurate elevation information is a necessity for conservation and management of tidal salt marshes where elevation differences can be as little as 2 m and ...

ABSTRACT: Digital terrain models (DTM) have become a commonly used source of data describing the shape of the Earth. Resolution determines the level of details that can be represented in this model. Changing the resolution influences the accuracy of the DTM. The effect of a resolution is even more clearly seen in slope and aspect calculation. Despite the resolution, there are different methods ...

This study tried to analyze error range and resolution of drone images using a rotary wing by comparing them with field measurement results and to analyze stands patterns in actual vegetation map preparation by comparing drone images with aerial images provided by National Geographic Information Institute of Korea. A total of 11 ground control points (GCPs) were selected in the area, and coordi...

• Future climate and hydrological variables were simulated at a high resolution. The components of two mesoscale Alpine catchments explored. Snowmelt drives future streamflow changes elevations. Liquid rainfall influences lower Changes to means extremes are elevation season dependent. Mountainous cover broad range elevations their response warming is expected vary significantly in space. Nevert...

BACKGROUND The use of fractional flow reserve (FFR) in acute coronary syndromes is controversial. The British Heart Foundation Fractional Flow Reserve Versus Angiography in Guiding Management to Optimize Outcomes in Non-ST-Elevation Myocardial Infarction (FAMOUS-NSTEMI) study (NCT01764334) has recently demonstrated the safety and feasibility of FFR measurement in patients with non-ST-segment-el...