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Vegetation fraction is an important indicator of ecosystem change, a high spatial and temporal resolution vegetation fraction product was essential in many spatially distributed models. Recent developments of coarse resolution remote sensing (e.g. MODIS) provide the potential to estimate the vegetation fraction with a high temporal resolution. However, coarse resolution products usually provide insufficient...
Agriculture in both industrialized and developing countries is a unique sector, characterized by complex issues and problems, ranging from macro (economic) policy levels all the way to the micro (smallholder) farming household and field plot levels. Agriculture, being predominantly a (small-scale) family and/or communal enterprise differs in fundamental ways from administrative services and industrial...
The COSMO-SkyMed® X-band SAR satellites constellation, due to its capability to acquire dense temporal data series at very high to high ground resolution and in co and cross-polarizations, is a promising system for crops monitoring and management. Its use, in combination with other SAR and optical systems in a virtual constellation, can result in a very effective tool for agricultural practice monitoring,...
BFAST (Breaks For Additive Seasonal and Trend) method and MODIS NDVI data were used to detect vegetation dynamics in Quebec during the period of 2000–2012. The Permanent Sample Plots (PSP) data were used to assess the detection method. The results demonstrated that 25.68% of the study area experienced NDVI trend changes during the research period. The detected timing of the biggest changes showed...
Forest fire is one of the dominant disturbance regimes, especially in boreal forests. Identifying post-fire forest dynamics is crucial to both ecological research and forest monitoring and management. In this study, taking the most serious forest fire in the history of P. R. China as an example, we proposed to monitor the temporal and spatial characteristics of post-fire forest dynamics using MODIS...
High-quality leaf area index (LAI) products retrieved from satellite observations are urgently needed for crop growth monitoring and yield estimation, land-surface process simulation and global change studies. Currently many LAI products are produced from different satellites. However, those products are usually limited to certain resolutions and some of them are incomplete in space. So these products...
In this study, a novel method was proposed for estimation of effective plant area index (PAI) from Terrestrial Laser Scanner (TLS) data. Integrating vertical and tilt scanning from Terrestrial laser scanner, discrete directional canopy gap fraction could be calculated and effective PAI could be estimated from canopy gap fraction. Finally, the effective PAI estimated from Terrestrial LiDAR are validated...
This paper aims to use unique features of hyperspectral data on an automatic process for outlining individual tree crowns (ITCs) in a tropical forest area, with special focus on semi-deciduous species. In order to enhance biophysical and biochemical properties of canopy species, a set of vegetation indices were computed. These indices served as input for a region growing segmentation algorithm that...
In this paper a system for the fusion of hyperspectral and airborne laser scanning (ALS) data for the estimation of forest attributes is presented. In particular we focused on the classification of tree species, the estimation of stem diameter at breast height (DBH) and the estimation of the stem volume. The results showed that the fusion of hyperspectral and ALS data improve the estimation results...
In this work a new lightweight LiDAR solution designed for UAV application will be investigated. In particular, we show that using this multi-echo LiDAR it is possible to obtain DTM reconstruction of the densely forested area surveyed in good agreement with the local technical regional map (CTR). We have also estimated the mean height of the trees from the estimated CHM with relative error equal to...
Terrestrial LiDAR systems have received lots of attention on three-dimensional (3D) structure reconstruction for trees, especially on the branches skeleton generation. On this basis, a method is proposed to add leaves structures based on point density by dividing small cube in the canopy to reduce the influence of uneven distribution of point cloud, combining gap fraction model to retrieve leaf area...
Timely and accurate measurements of forest parameters are critical for ecosystem studies, sustainable forest resources management, monitoring and planning. This paper presents a processing chain for individual tree segmentation over large areas with airborne LiDAR 3D point cloud and very high resolution (VHR) optical imagery. The proposed processing chain consists of forest stand level delineation...
Climate and land-atmosphere models rely on accurate land-surface parameters, such as the Fraction of Absorbed Photo synthetically Active Radiation (FAPAR). It is known that FAPAR values retrieved from remote sensing images suffer from scaling effects. Scaling transformation aims to derive accurate FAPAR values at a specific scale from values at other scales. In this paper, scaling effect mechanism...
Forest canopy leaf area index (LAI) is an important biological parameter and an evaluation index of the vegetation canopy. It is difficult to get LAI through direct inversion using Li-Strahler geometric-optical model (GOMS)[1,2]. In this paper, LAI is introduced into the GOMS model as an independent variable to substitute other canopy structure parameters. The verification results well demonstrated...
Row crop is an important cultivation form in China. It is considered to be a transitional canopy structure between continuous vegetation and discrete vegetation. Lots of physical models of row crop were established to invert vegetation parameters of row crop. Monte Carlo model is a reliable reference for those physical models. In this paper, row crop was modeled as a series of parallel rectangles...
Various remote sensing technologies are utilized to monitor tropical forest for REDD project. In developing countries, the accuracy of field measurement does not satisfy the quality required for the validation of satellite remotely sensed data. Therefore, we introduce the most portable laser sensor, SICK LMS511, to measure trees in the field of tropical forest and the semi-automatic process to derive...
Obtaining reliable vegetation optical depth (τ, tau) is essential for vegetation parameter estimation and soil moisture retrieval. In this paper, a lookup table method was developed to retrieve optical depth using MVIs, which can derive the optical depth and single scattering albedo simultaneously without any auxiliary data. The lookup table method is based on the relationship of the single scattering...
We demonstrate a method for estimating the leaf area density (LAD) distribution of individual trees using multi-echo airborne light detection and ranging (LiDAR). This method improves upon the previously developed method which calculates LAD based on the contact frequency between the laser beams and leaves by tracing the paths of the laser beams. The proposed method exploits the last and intermediate...
Statistics provided by the European Join Research Centre (JRC) in Ispra/Italy show that Poland is a third European country after Portugal and Spain in number of fires reported annually. The aim of this study was to assess if and how Earth Observation data can support the existing ground-based Forest Fire Information System in Poland. We have examined a sets of spaceborne data and products, i.e. Active...
Grassland wildfires have profound immediate effects on ecosystems. A wildfire that occurred in Grasslands National Park (GNP) on April 27th 2013 has severely disturbed the local ecosystem. This study was thus conducted to evaluate impacts of the fire on this semi-arid grassland. Spectral indices including Normalized Burn Ratio (NBR), Mid-Infrared Burn Index (MIRBI), and Normalized Difference Vegetation...
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