Meteorologists use shapes and movements of clouds in satellite images as indicators of several major types of severe storms. Yet, because satellite image data are in increasingly higher resolution, both spatially and temporally, meteorologists cannot fully leverage the data in their forecasts. Automatic satellite image analysis methods that can find storm-related cloud patterns are thus in demand. We propose a machine learning and pattern recognition-based approach to detect “comma-shaped” clouds in satellite images, which are specific cloud distribution patterns strongly associated with cyclone formulation. In order to detect regions with the targeted movement patterns, we use manually annotated cloud examples represented by both shape and motion-sensitive features to train the computer to analyze satellite images. Sliding windows in different scales ensure the capture of dense clouds, and we implement effective selection rules to shrink the region of interest among these sliding windows. Finally, we evaluate the method on a hold-out annotated comma-shaped cloud data set and cross match the results with recorded storm events in the severe weather database. The validated utility and accuracy of our method suggest a high potential for assisting meteorologists in weather forecasting.
The detection of clouds within a satellite image is essential for retrieving surface geophysical parameters from optical and thermal imagery. Even a small percentage of cloud cover within a radiometer pixel can adversely affect the determination of surface variables such as albedo and temperature. Thus, onboard processing of satellite data requires reliable automated cloud detection algorithms that are applicable to a wide range of surface types. Unfortunately cloud-detection, particularly over snow- and ice-covered surfaces, is a problem that plagues the field of remote sensing because of the lack of spectral contrast. This paper discusses preliminary results based on kernel methods for unsupervised discovery of snow, ice, clouds, and other geophysical processes based on data from the MODIS instrument and discusses implementation in computationally constrained environments such as those found on satellites. Current techniques for cyclone detection and tracking employ NCEP (National Centers for Environmental Prediction) models from in-situ measurements. This solution does not provide true global coverage, unlike remote satellite observations. However it is impractical to use a single Earth orbiting satellite to detect and track events such as cyclones in a continuous manner due to limited spatial and temporal coverage. One solution to alleviate such persistent problems is to utilize heterogeneous sensor data from multiple orbiting satellites. However, this solution requires overcoming other new challenges such as varying spatial and temporal resolution between satellite sensor data, the need to establish correspondence between features from different satellite sensors, and the lack of definitive indicators for cyclone events in some sensor data. We describe an automated cyclone discovery and tracking approach using heterogeneous near real-time sensor data from multiple satellites. This approach addresses the unique challenges associated with knowledge discovery and mining from heterogeneous satellite data streams. We consider two remote sensor measurements in our current implementation, namely: QuikSCAT wind satellite measurements, and merged precipitation data from TRMM and other satellites. More satellites will be incorporated in the near future and our solution is sufficiently powerful that it generalizes to multiple sensor measurement modalities. Our approach consists of three main components: (i) feature extraction from each sensor measurement, (ii) an ensemble classifier for cyclone discovery, and (iii) knowledge sharing between the different remote sensor measurements based on a linear Kalman filter for predictive cyclone tracking. Experimental results on historical hurricane datasets demonstrate the superior performance of our approach compared to previous work. We present an automatic and integrated neural network-based tropical cyclone (TC) identification and track mining system. The proposed system consists of two main modules: 1) TC pattern identification system using neural oscillatory elastic graph matching model; and 2) TC track mining system using hybrid radial basis function network with time difference and structural learning algorithm. For system evaluation, 120 TC cases appeared in the period between 1985 and 1998 provided by National Oceanic and Atmospheric Administration are being used. Comparing with the bureau numerical TC prediction model used by Guam and the enhanced model proposed by (1991), the proposed hybrid RBF has attained an over 30 and 18 improvement in forecast errors. Tracking both structure and motion of nonrigid objects from monocular images is an important problem in vision. In this paper, a hierarchical method which integrates local analysis (that recovers small details) and global analysis (that appropriately limits possible nonrigid behaviors) is developed to recover dense depth values and nonrigid motion from a sequence of 2D satellite cloud images without any prior knowledge of point correspondences. This problem is challenging not only due to the absence of correspondence information but also due to the lack of depth cues in the 2D cloud images (scaled orthographic projection). In our method, the cloud images are segmented into several small regions and local analysis is performed for each region. A recursive algorithm is proposed to integrate local analysis with appropriate global fluid model constraints, based on which a structure and motion analysis system, SMAS, is developed. We believe that this is the first reported system in estimating dense structure and nonrigid motion under scaled orthographic views using fluid model constraints. Experiments on cloud image sequences captured by meteorological satellites (GOES-8 and GOES-9) have been performed using our system, along with their validation and analyses. Both structure and 3D motion correspondences are estimated to subpixel accuracy. Our results are very encouraging and have many potential applications in earth and space sciences, especially in cloud models for weather prediction.  Abstract Extensive observations were made of a winter storm that crossed eastern Canada on 10–12 March 1986 during the Canadian Atlantic Storms Program (CASP) field project. A kinematic description of the storm is established by using isentropic analyses and this description is compared with storm observations in other regions as well as with other CASP storms. The occurrence and role of snow and freezing precipitation in this storm are highlighted. It is suggested that the evolution and organization of the storm was greatly influenced by mesoscale circulations driven by melting snow. Computers are widely utilized in today’s weather forecasting as a powerful tool to leverage an enormous amount of data. Yet, despite the availability of such data, current techniques often fall short of producing reliable detailed storm forecasts. Each year severe thunderstorms cause significant damage and loss of life, some of which could be avoided if better forecasts were available. We propose a computer algorithm that analyzes satellite images from historical archives to locate visual signatures of severe thunderstorms for short-term predictions. While computers are involved in weather forecasts to solve numerical models based on sensory data, they are less competent in forecasting based on visual patterns from both current and past satellite images. In our system, we extract and summarize important visual storm evidence from satellite image sequences in the way that meteorologists interpret the images. In particular, the algorithm extracts and fits local cloud motion from image sequences to model the storm-related cloud patches. Image data from the year 2008 have been adopted to train the model, and historical severe thunderstorm reports in continental U.S. from 2000 to 2013 have been used as the ground truth and priors in the modeling process. Experiments demonstrate the usefulness and potential of the algorithm for producing more accurate severe thunderstorm forecasts. Cloud motion vectors derived from sequences of remotely sensed data are widely used by numerical weather prediction models and other meteorological and climatic applications. One approach to computing cloud motion vectors is the correlation-relaxation labeling technique, in which a set of candidate vectors for each template is refined using relaxation labeling to provide a local smoothness constraint. In this letter, an extension of the correlation-relaxation labeling framework to tracking clouds in multichannel imagery is presented. As this multichannel approach takes advantage of the diversity between channels, it has the potential for producing motion vectors with a superior quality and coverage than can be achieved by any individual channel. Results for visible and infrared images from Meteostat Second Generation confirm the benefits of the multichannel approach  