The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The Lena River basin in Siberia produces one of the largest river inflows into the Arctic Ocean. One of the most important sources of runoff to the river is spring snowmelt, and therefore, snow ablation processes have great importance for this basin. Vegetation and accumulated snowfall control the spatial distribution of sublimation, which is found to have a considerable effect on the snow ablation...
Hyperspectral remote sensing data have great potential to identify ground objects and classify tree species. However, the tree species classification based on hyperspectral data in the subtropical region of hilly landscape have always been challenged by rugged topography. We conducted our research in subtropical mountainous forests in Pu'er of Yunnan province in southwestern China. This research investigated...
Satellite image classification is a key task used in remote sensing for the automatic interpretation of a large amount of information. Today there exist many types of classification algorithms using advanced image processing methods enhancing the classification accuracy rate. One of the best state-of-the-art methods which improves significantly the classification of complex scenes relies on Self-Dual...
The spectral within- and between-class variability of reed beds and reference species was evaluated in this study in order to determine the possibilities to discriminate reed beds from other green vegetation using airborne hyperspectral data. Five reed bed and five reference sites representing other greenish vegetation were chosen for this study, 15 sample plots at each site. The differences in within-class...
Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake in East Asia (EA). Pollen record reflected the dynamics of vertical vegetation zones and temperature change. Spectral analysis on pollen percentages/concentrations of Pinus and Quercus, and a temperature proxy, revealed ∼500-year quasi-periodic cold-warm fluctuations during the past 5350 years. This ∼500-year...
New high resolution Satellite Image Time Series (SITS) are becoming crucial to land cover mapping over large areas. Their high temporal resolution will allow to better depict scene dynamics. However, it will also increase the amount of data to process. The classification of these data involves therefore new challenges such as: (1) selecting the best feature set to use as input data, (2) dealing with...
Data synergy or fusion is a mechanism whereby discrete types of data are used together to achieve a better understanding than was possible with each individually. Spanning over 30% of the Earth's landmass, the global forest plays a significant role in numerous planetary systems including the carbon cycle. This paper presents a novel approach to estimating forest aboveground biomass and mean canopy...
Forest vertical canopy cover (VCC) is an essential factor to be considered during forest resource inventory, sub-compartment division and thinning intensity. In order to monitor the forest canopy structure changes over the Greater Khingan, two temporal (2005 and 2010) forest VCC are derived by inverting the Li-Strahler geometric-optical model (GO) based on the extracted endmembers. The results show...
Mapping vegetation in the tropics is of primary importance to assess its contribution to important ecosystem services. This implies to implement methods to capture the vegetation gradient that characterizes land cover in these regions. Linear Mixture Models have long been used to monitor this gradient. In the present study, we automatically unmixed six Landsat 8 images of a study area in the Republic...
A potential application of LiDAR data in street-level greenery assessment has been explored in this study. Taking full advantage of the fine-scale tree structure modeling of LiDAR data, we propose a new green view index calculation method to assess street greenery visualization. Results indicate that LiDAR data is capable of differentiating the amount of greenness being perceived from different sites...
The red palm weevil (RPW) is a dangerous invasive insect species that is causing severe damage to date palm trees around the world. This study focuses for the first time on the detection and discrimination among different stages of RPW stress-attacks using bio-physiological spectral indices and statistical analysis of satellite image data. A total of 27 different indices were assessed using new technology...
Oil palm is recognized as the golden crop. It produces the highest oil yield among oil seed crops. Malaysia, as the world's second largest producer of palm oil, has 16 % of its lands planted with oil palms. Multisensor remote sensing plays an important role by providing relevant, timely and accurate information that can be developed into a plantation monitoring system to optimize production and sustainability...
Individual tree crown delineation (ITCD), which includes treetop detection and/or tree crown delineation, plays a significant role in modern forest resources management and precise forestry. Recent years, amount of ITCD algorithms have been proposed based on passive and active remotely sensed data. However, since there is no standardized accuracy assessment procedure for ITCD, it is extremely difficult...
The objective of this study was to improve individual tree crown delineation by fully exploiting the crown information exhibited in multi-wavelength LiDAR data. The data used in this study were obtained by an Optech's Titan instrument with three wavelengths: 532 nm, 1064 nm, and 1550 nm. Methods were developed to employ both spectral and structural information of tree crowns to separate crowns from...
Conventional methods for classifying SAR data, such as H-α decomposition, Wishart classifier etc. are quite complex and classifies data only on the basis of polarimetric information. With the advent of distinct feature types, their role in land cover classification using SAR data could be analysed. For the sake of classification, researchers are extracting and combining several features in order to...
During the last decade unmanned aerial systems (UAS) have been intensively applied to create 3-dimensional models of land surface features for various applications. Although, UAS data can be jointly used with airborne LiDAR data to generate a canopy height model (CHM) of forest stands, it is rare to find research concerned the generation of forest CHM using only UAS data. This paper investigate a...
Effective vegeation optical depth (VOD) is widely used for land surface parameters retrieval. It is necessary to reseach the relationship between the effective value and the theoretical value of VOD. In this paper, we have used a least square method to obtain effective VOD using simulation data and explore the relationship between effective VOD and theoretical VOD. This research might contribute to...
For the past three years, the University of Massachusetts and Harvard Forest have been working on an automated system for collecting remote sensing data about a regrowing region in Petersham, Massachusetts. The system consists of a two 15 m towers separated by a 50 m span and connected to one another by a pair of taut cables which support a tram that can travel between the two towers. This paper will...
The accurate multi-polarization 3–10 GHz frequency-domain data of some small trees are obtained by indoor wideband polarimetric scattering measurement system. The relationship between differential extinction coefficient and returned power is quantitatively derived, and the fluctuating of differential extinction coefficient changed with frequency is analyzed by combining the morphological characteristics...
Resent years, sparse representation theory has been widely used in signal processing field. Researchers introduce this theory into the application of pattern recognition and classification and get the sparse representation classifier (SRC). In this paper, we use the SRC to achieve the classification of LiDAR (Light Detection and Ranging) points. To get a better performance, we introduce the kernel...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.