107 research outputs found
Nature Inspired Optimization Techniques For Flood Assesment And Land Cover Mapping Using Satellite Images
With the advancement of technology and the development of more sophisticated remote sensing sensor systems, the use of satellite imagery has opened up various fields of exploration and application. There has been an increased interest in analysis of multi-temporal satellite image in the past few years because of the wide variety of possible applications of in both short-term and long-term image analysis. The type of changes that might be of interest can range from short-term phenomena such as flood assessment and crop growth stage, to long-term phenomena such as urban fringe development. This thesis studies flood assessment and land cover mapping of satellite images, and proposes nature inspired algorithms that can be easily implemented in realistic scenarios.
Disaster monitoring using space technology is one of the key areas of research with vast potential; particularly flood based disasters are more challenging. Every year floods occur in many regions of the world and cause great losses. In order to monitor and assess such situations, decision-makers need accurate near real-time knowledge of the field situation. How to provide actual information to decision-makers for effective flood monitoring and mitigation is an important task, from the point of view of public welfare. Over-estimation of the flooded area leads to over-compensation to people, while under-estimation results in production loss and negative impacts on the population. Hence it is essential to assess the flood damage accurately, both in qualitative and quantitative terms. In such situations, land cover maps play a very critical role. Updating land cover maps is a time consuming and costlier operation when it is performed using traditional or manual methods. Hence, there is a need to find solutions for such problem through automation.
Design of automatic systems dedicated to satellite image processing which involves change detection to discriminate areas of land cover change between imaging dates. The system integrates the spectral and spatial information with the techniques of image registration and pattern classification using nature inspired techniques. In the literature, various works have been carried out for solving the problem of image registration and pattern classification using conventional methods. Many researchers have proved, for different situations, that nature inspired techniques are promising in comparison with that of conventional methods. The main advantage of nature inspired technique over any other conventional methods is its stochastic nature, which converges to optimal solution for any dynamic variation in a given satellite image. Results are given in such terms as to delineate change in multi-date imagery using change-versus-no-change information to guide multi-date data analysis.
The main objective of this study is to analyze spatio-temporal satellite data to bring out significant changes in the land cover map through automated image processing methods.
In this study, for satellite image analysis of flood assessment and land cover mapping, the study areas and images considered are: Multi-temporal MODerate-resolution Imaging Spectroradiometer (MODIS) image around Krishna river basin in Andhra Pradesh India; Linear Imaging Self Scanning Sensor III (LISS III)and Synthetic Aperture Radar(SAR)image around Kosi river basin in Bihar, India; Landsat7thematicmapperimage from the southern part of India; Quick-Bird image of the central Bangalore, India; Hyperion image around Meerut city, Uttar Pradesh, India; and Indian pines hyperspectral image.
In order to develop a flood assessment framework for this study, a database was created from remotely sensed images (optical and/or Synthetic Aperture Radar data), covering a period of time.
The nature inspired techniques are used to find solutions to problems of image registration and pattern classification of a multi-sensor and multi-temporal satellite image. Results obtained are used to localize and estimate accurately the flood extent and also to identify the type of the inundated area based on land cover mapping.
The nature inspired techniques used for satellite image processing are Artificial Neural Network (ANN), Genetic Algorithm (GA),Particle Swarm Optimization (PSO), Firefly Algorithm(FA),Glowworm Swarm Optimization(GSO)and Artificial Immune System (AIS).
From the obtained results, we evaluate the performance of the methods used for image registration and pattern classification to compare the accuracy of satellite image processing using nature inspired techniques.
In summary, the main contributions of this thesis include (a) analysis of flood assessment and land cover mapping using satellite images and (b) efficient image registration and pattern classification using nature inspired algorithms, which are more popular than conventional optimization methods because of their simplicity, parallelism and convergence of the population towards the optimal solution in a given search space
A novel approach for multispectral satellite image classification based on the bat algorithm
Amongst the multiple advantages and applications of remote sensing, one of the most important use is to solve the problem of crop classification, i.e., differentiating between various crop types. Satellite images are a reliable source for investigating the temporal changes in crop cultivated areas. In this work, we propose a novel Bat Algorithm (BA) based clustering approach for solving crop type classification problems using a multi-spectral satellite image. The proposed partitional clustering algorithm is used to extract information in the form of optimal cluster centers from training samples. The extracted cluster centers are then validated on test samples. A real-time multi-spectral satellite image and one benchmark dataset from the UCI repository are used to demonstrate robustness of the proposed algorithm. The performance of the Bat Algorithm is compared with the traditional K-means and two other nature-inspired metaheuristic techniques, namely, Genetic Algorithm and Particle Swarm Optimization. From the results obtained, we can conclude that BA can be successfully applied to solve crop type classification problems
Metacognitive Decision Making Framework for Multi-UAV Target Search Without Communication
This paper presents a new Metacognitive Decision Making (MDM) framework
inspired by human-like metacognitive principles. The MDM framework is
incorporated in unmanned aerial vehicles (UAVs) deployed for decentralized
stochastic search without communication for detecting stationary targets
(fixed/sudden pop-up) and dynamic targets. The UAVs are equipped with multiple
sensors (varying sensing capability) and search for targets in a largely
unknown area. The MDM framework consists of a metacognitive component and a
self-cognitive component. The metacognitive component helps to self-regulate
the search with multiple sensors addressing the issues of
"which-sensor-to-use", "when-to-switch-sensor", and "how-to-search". Each
sensor possesses inverse characteristics for the sensing attributes like
sensing range and accuracy. Based on the information gathered by multiple
sensors carried by each UAV, the self-cognitive component regulates different
levels of stochastic search and switching levels for effective searching. The
lower levels of search aim to localize the search space for the possible
presence of a target (detection) with different sensors. The highest level of a
search exploits the search space for target confirmation using the sensor with
the highest accuracy among all sensors. The performance of the MDM framework
with two sensors having low accuracy with wide range sensor for detection and
increased accuracy with low range sensor for confirmation is evaluated through
Monte-Carlo simulations and compared with six multi-UAV stochastic search
algorithms (three self-cognitive searches and three self and social-cognitive
based search). The results indicate that the MDM framework is efficient in
detecting and confirming targets in an unknown environment.Comment: 12 pages, 9 figures, 9 table
Automatic detection of powerlines in UAV remote sensed images
Powerline detection is one of the important applications of Uninhabited Aerial Vehicle (UAV ) based remote sensing. In this paper, powerlines are detected from UAV remote sensed images. The images are acquired from a Quad rotor UAV fitted with a GoPro® camera. In the proposed method pixel intensity-based clustering is performed followed by morphological operations. K-means clustering is applied for clustering. The number of clusters to be used in k-means clustering is automatically generated using Davies-Bouldin (DB) index. Further, the clustered data is processed to improvise the extraction using mathematical morphological operations. Performance of powerline extraction is analysed using confusion matrix method. In the observed results of powerline extraction using DB index, evaluation features derived from confusion matrix is close to one, indicating good classification
A novel approach for multispectral satellite image classification based on the bat algorithm
Amongst the multiple advantages and applications of remote sensing, one of the most important use is to solve the problem of crop classification, i.e., differentiating between various crop types. Satellite images are a reliable source for investigating the temporal changes in crop cultivated areas. In this work, we propose a novel Bat Algorithm (BA) based clustering approach for solving crop type classification problems using a multi-spectral satellite image. The proposed partitional clustering algorithm is used to extract information in the form of optimal cluster centers from training samples. The extracted cluster centers are then validated on test samples. A real-time multi-spectral satellite image and one benchmark dataset from the UCI repository are used to demonstrate robustness of the proposed algorithm. The performance of the Bat Algorithm is compared with the traditional K-means and two other nature-inspired metaheuristic techniques, namely, Genetic Algorithm and Particle Swarm Optimization. From the results obtained, we can conclude that BA can be successfully applied to solve crop type classification problems
Towards deep generation of guided wave representations for composite materials
Laminated composite materials are widely used in most fields of engineering.
Wave propagation analysis plays an essential role in understanding the
short-duration transient response of composite structures. The forward
physics-based models are utilized to map from elastic properties space to wave
propagation behavior in a laminated composite material. Due to the
high-frequency, multi-modal, and dispersive nature of the guided waves, the
physics-based simulations are computationally demanding. It makes property
prediction, generation, and material design problems more challenging. In this
work, a forward physics-based simulator such as the stiffness matrix method is
utilized to collect group velocities of guided waves for a set of composite
materials. A variational autoencoder (VAE)-based deep generative model is
proposed for the generation of new and realistic polar group velocity
representations. It is observed that the deep generator is able to reconstruct
unseen representations with very low mean square reconstruction error. Global
Monte Carlo and directional equally-spaced samplers are used to sample the
continuous, complete and organized low-dimensional latent space of VAE. The
sampled point is fed into the trained decoder to generate new polar
representations. The network has shown exceptional generation capabilities. It
is also seen that the latent space forms a conceptual space where different
directions and regions show inherent patterns related to the generated
representations and their corresponding material properties
Explainable machine learning to enable high-throughput electrical conductivity optimization of doped conjugated polymers
The combination of high-throughput experimentation techniques and machine
learning (ML) has recently ushered in a new era of accelerated material
discovery, enabling the identification of materials with cutting-edge
properties. However, the measurement of certain physical quantities remains
challenging to automate. Specifically, meticulous process control,
experimentation and laborious measurements are required to achieve optimal
electrical conductivity in doped polymer materials. We propose a ML approach,
which relies on readily measured absorbance spectra, to accelerate the workflow
associated with measuring electrical conductivity. The first ML model
(classification model), accurately classifies samples with a conductivity >~25
to 100 S/cm, achieving a maximum of 100% accuracy rate. For the subset of
highly conductive samples, we employed a second ML model (regression model), to
predict their conductivities, yielding an impressive test R2 value of 0.984. To
validate the approach, we showed that the models, neither trained on the
samples with the two highest conductivities of 498 and 506 S/cm, were able to,
in an extrapolative manner, correctly classify and predict them at satisfactory
levels of errors. The proposed ML workflow results in an improvement in the
efficiency of the conductivity measurements by 89% of the maximum achievable
using our experimental techniques. Furthermore, our approach addressed the
common challenge of the lack of explainability in ML models by exploiting
bespoke mathematical properties of the descriptors and ML model, allowing us to
gain corroborated insights into the spectral influences on conductivity.
Through this study, we offer an accelerated pathway for optimizing the
properties of doped polymer materials while showcasing the valuable insights
that can be derived from purposeful utilization of ML in experimental science.Comment: 33 Pages, 17 figure
SIFT-FANN: An efficient framework for spatio-spectral fusion of satellite images
Image fusion techniques are widely used for remote sensing data. A special application is for using low resolution multi-spectral image with high resolution panchromatic image to obtain an image having both spectral and spatial information. Alignment of images to be fused is a step prior to image fusion. This is achieved by registering the images. This paper proposes the methods involving Fast Approximate Nearest Neighbor (FANN) for automatic registration of satellite image (reference image) prior to fusion of low spatial resolution multi-spectral QuickBird satellite image (sensed image) with high spatial resolution panchromatic QuickBird satellite image. In the registration steps, Scale Invariant Feature Transform (SIFT) is used to extract key points from both images. The keypoints are then matched using the automatic tuning algorithm, namely, FANN. This algorithm automatically selects the most appropriate indexing algorithm for the dataset. The indexed features are then matched using approximate nearest neighbor. Further, Random Sample Consensus (RanSAC) is used for further filtering to obtain only the inliers and co-register the images. The images are then fused using Intensity Hue Saturation (IHS) transform based technique to obtain a high spatial resolution multi-spectral image. The results show that the quality of fused images obtained using this algorithm is computationally efficient
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