Publicações

An algorithm for automatic detection and orientation estimation of planar structures in LiDAR-scanned outcrops

The spatial orientation of linear and planar structures in geological fieldwork is still obtained using simple hand-held instruments such as a compass and clinometer. Despite their ease of use, the amount of data obtained in this way is normally smaller than would be considered as representative of the area available for sampling. LiDAR-based remote sensors [...]

An Automatic Algorithm for Minimizing Anomalies and Discrepancies in Point Clouds Acquired by Laser Scanning Technique

Laser scanning technique from airborne and land platforms has been largely used for collecting 3D data in large volumes in the field of geosciences. Furthermore, the laser pulse intensity has been widely exploited to analyze and classify rocks and biomass, and for carbon storage estimation. In general, a laser beam is emitted, collides with targets [...]

3-D Recosntruction Of Digital Outcrop Model Based on Multiple View Images and Terrestrial Laser Scanning

This paper presents a comparative study about 3D reconstruction based on active and passive sensors, mainly LiDAR – Terrestrial Laser Scanner (TLS) and raster images (photography), respectively. An accuracy analysis has been performed in the positioning of outcrop point clouds obtained by both techniques. To make the comparison feasible, datasets are composed by point clouds [...]

Monitoring Heat Waves and Their Impacts on Summer Crop Development in Southern Brazil

Periods in the soybean summer cycle that are sensitive to the occurrence of high temperatures were studied. An analysis was performed on the variability of soybean yields associated with crop canopy temperatures during key development periods. A land surface temperature (LST) data series from MODIS (Moderate Resolution Imaging Spectroradiometer) on the Aqua satellite was processed [...]

Assessing the MODIS Crop Detection Algorithm for Soybean Crop Area Mapping and Expansion in the Mato Grosso State, Brazil

Estimations of crop area were made based on the temporal profiles of the Enhanced Vegetation Index (EVI) obtained from moderate resolution imaging spectroradiometer (MODIS) images. Evaluation of the ability of the MODIS crop detection algorithm (MCDA) to estimate soybean crop areas was performed for fields in the Mato Grosso state, Brazil. Using the MCDA approach, [...]

Combining SRP-PHAT and two Kinects for 3D Sound Source Localization

The Kinect™ has been developed to recognize gestures and voice commands, through a set of cameras and microphones, respectively. This paper proposes and evaluates low-cost Sound Source Localization (SSL) solution based this off-the-shelf equipment. It consists of employing a pair of Kinect devices as an alternative for microphone array, and executing the Steered Response Power [...]

Spectral Pattern Classification in Lidar Data for Rock Identification in Outcrops

The present study aimed to develop and implement a method for detection and classification of spectral signatures in point clouds obtained from terrestrial laser scanner in order to identify the presence of different rocks in outcrops and to generate a digital outcrop model. To achieve this objective, a software based on cluster analysis was created, [...]

Automatic on-the-fly extrinsic camera calibration of onboard vehicular cameras

This paper presents an on-the-fly procedure for obtaining extrinsic camera parameters of onboard vehicular cameras, as well as augmented reality applications for driver assistance systems and road inspection. The proposed approach employs a lane detection algorithm to extract the lane boundaries of the road, and estimates the distance between adjacent lane markings based on the [...]

Spectral Model for Soybean Yield Estimate Using MOD-IS/EVI Data

Attaining reliable and timely agricultural estimates is very important everywhere, and in Brazil, due to its characteristics, this is especially true. In this study, estimations of crop production were made based on the temporal profiles of the Enhanced Vegetation Index (EVI) obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) images. The objective was to evaluate the [...]

GPU-based approaches for real-time sound source localization using the SRP-PHAT algorithm

In most microphone array applications, it is necessary to localize sound sources in a noisy and reverberant environment. For that purpose, many different Sound Source Localization (SSL) algorithms have been proposed, where the SRP-PHAT (Steered Response Power using the Phase Transform) has been known as one of the state-of-the-art methods. Its original formulation allows two [...]

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