Download or read book Application of Passive and Active Microwave Remote Sensing for Snow Water Equivalent Estimation written by Jinmei Pan and published by . This book was released on 2017 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Snow accumulation on the ground changes the energy balance between the land and the atmosphere, and stores winter precipitation for water supplies in many parts of the world. In practice, the snow water equivalent (SWE), defined as the equivalent depth of liquid water when snow completely melts, is difficult to map in cold regions except via remote sensing techniques. The microwave remote sensing (MWRS) has been used for SWE estimation since the 1980s based on the interactions of microwave radiation with snow crystals. In this study, physically based radiative transfer (RT) models and the Bayesian-based Markov Chain Monte Carlo (MCMC) approach were applied to develop a high-accuracy SWE retrieval algorithm. The models and the algorithms were tested using ground-based snowpit and microwave measurements. Two widely-used snow RT models were fully-compared in the aspects of snow micro-structure assumptions, volume scattering theories and the RT equation resolution. The Microwave Emission Model of Layered Snowpacks (MEMLS) based on the Improved Born Approximation (IBA) was shown to be an adequate observation model to estimate SWE using the multi-frequency brightness temperature (TB) at 10.65 to 90 GHz. The prior information is from a set of globally-available datasets, and the performance is tested for local prior information derived from historical ground measurements. The retrieval algorithm was later adapted for active microwave SWE retrieval using the backscattering coefficient at 10.2 to 16.7 GHz. Results showed that MEMLS-IBA can simulate the measured microwave signals with a 10-K accuracy for TB and a 1-dB accuracy for the backscattering coefficient. The passive microwave retrieval algorithm achieved an accuracy of 30-mm for shallow snow, with two-layer snow properties estimated. However, the active microwave retrieval algorithm reproduced similar accuracy only in the synthetic experiment using 1-layer snow property estimates. Future improvement requires a better active microwave observation model.
Download or read book Microwave Indices from Active and Passive Sensors for Remote Sensing Applications written by Emanuele Santi and published by MDPI. This book was released on 2019-10-21 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Past research has comprehensively assessed the capabilities of satellite sensors operating at microwave frequencies, both active (SAR, scatterometers) and passive (radiometers), for the remote sensing of Earth’s surface. Besides brightness temperature and backscattering coefficient, microwave indices, defined as a combination of data collected at different frequencies and polarizations, revealed a good sensitivity to hydrological cycle parameters such as surface soil moisture, vegetation water content, and snow depth and its water equivalent. The differences between microwave backscattering and emission at more frequencies and polarizations have been well established in relation to these parameters, enabling operational retrieval algorithms based on microwave indices to be developed. This Special Issue aims at providing an overview of microwave signal capabilities in estimating the main land parameters of the hydrological cycle, e.g., soil moisture, vegetation water content, and snow water equivalent, on both local and global scales, with a particular focus on the applications of microwave indices.
Download or read book Estimating Snow Water Resources from Space written by Dongyue Li and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Improving the estimation of snow water equivalent (SWE) in the Sierra Nevada is critical for the water resources management in California. In this study, we carried out an experiment to estimate SWE in the Upper Kern Basin, Sierra Nevada, by assimilating AMSR-E observed brightness temperatures (Tb) into a coupled hydrology and radiative transfer model using an ensemble Kalman batch reanalysis. The data assimilation framework merges the complementary SWE information from modeling and observations to improve SWE estimates. The novelty of this assimilation study is that both the modeling and the radiance data processing were specifically improved to provide more information about SWE. With the enhanced SWE signals in both simulations and observations, the batch reanalysis stands a better chance of successfully improving the SWE estimates. The modeling was at a very high resolution (90m) and spanned a range of mountain environmental factors to better characterize the effects of the mountain environment on snow distribution and radiance emission. We have developed a dynamic snow grain size module to improve the radiance modeling during the intense snowfall events. The AMSR-E 37GHz V-pol observed Tb was processed at its native footprint resolution at ~100 square km. In the batch assimilation, the model predicted the prior SWE and Tb; the prior estimate of an entire year was then updated by the dry-season observations at one time. One advantage of this is that the prior SWE of a certain period is updated using the observations both before and after this period, which takes advantage of the temporally continuous signal of the seasonal snow accumulation in the observations. We found the posterior SWE estimates showed improved accuracy and robustness. During the study period of 2003 to 2008, at point-scale, the average bias of the six-year April 1st SWE was reduced from -0.17 m to -0.02m, the average temporal SWE RMSE of the snow accumulation season decreased by 51.2%. The basin-scale results showed that the April 1st SWE bias reduced from -0.17m to -0.11m, and the temporal SWE RMSE of the accumulation season decreased by 23.6%.
Download or read book Estimation of Snow Parameters Based on Passive Microwave Remote Sensing and Meteorological Information written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method to incorporate passive microwave remote sensing measurements within a spatially distributed snow hydrology model to provide estimates of the spatial distribution of Snow Water Equivalent (SWE) as a function of time is implemented. The passive microwave remote sensing measurements are at 25 km resolution. However, in mountain regions the spatial variability of SWE over a 25 km footprint is large due to topographic influences. On the other hand, the snow hydrology model has built-in topographic information and the capability to estimate SWE at a 1 km resolution. In our work, the snow hydrology SWE estimates are updated and corrected using SSM/I passive microwave remote sensing measurements. The method is applied to the Upper Rio Grande River Basin in the mountains of Colorado. The change in prediction of SWE from hydrology modeling with and without updating is compared with measurements from two SNOTEL sites in and near the basin. The results indicate that the method incorporating the remote sensing measurements into the hydrology model is able to more closely estimate the temporal evolution of the measured values of SWE as a function of time. Tsang, Leung and Hwang, Jenq-Neng Unspecified Center NAGw-4251...
Download or read book Electromagnetic Scattering of Dense Media with Application to Active and Passive Microwave Remote Sensing of Terrestrial Snow written by Wenmo Chang and published by . This book was released on 2014 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is of great importance to estimate the amount and the variation of water storage in the form of seasonal snowpack, in order to effectively monitor and manage the water resources all over the world. It is believed that significant temporal changes and spatial changes in local snowpack, regional snowpack and global snow are due to climate change. The Snow Water Equivalent (SWE) is defined as the depth of some hypothetical water which is melted instantaneously from an entire snowpack. Therefore the estimate of SWE is critical to the understanding of the water cycle, water resource management, prediction of climate change, flood forecasting, etc. Microwave remote sensing has been used in estimating SWE for decades. As radar measurement, radiometric measurement, and ground measurement data abound in microwave remote sensing campaigns, it is important to connect the ground measurement to electrical measurement by developing accurate physical models for snow, as well as scattering models for random medium. In this dissertation, Dense Media Radiative Transfer (DMRT) is combined with Quasi-Crystalline Approximation (QCA) and bicontinuous model. The DMRT-QCA and DMRT-bicontinuous are applied to data analysis of recent multi-frequency backscattering coefficients measurements in SnowSAR and SnowScat campaigns respectively. Then DMRT-bicontinuous model is used to study both active and passive remote sensing in the NoSREx campaign. Backscattering enhancement effect is considered. Lastly, the QCA model and the bicontinuous model are compared in microwave scattering as well as the medium characterization. The parameter extraction of these two models from ground measurement are discussed.
Download or read book Climate Impacts on Sustainable Natural Resource Management written by Pavan Kumar and published by John Wiley & Sons. This book was released on 2021-12-01 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: CLIMATE IMPACTS ON SUSTAINABLE NATURAL RESOURCE MANAGEMENT Climate change has emerged as one of the predominant global concerns of the 21st century. Statistics show that the average surface temperature of the Earth has increased by about 1.18°C since the late 19th century and the sea levels are rising due to the melting of glaciers. Further rise in the global temperature will have dire consequences for the survival of humans on the planet Earth. There is a need to monitor climatic data and associated drivers of changes to develop sustainable planning. The anthropogenic activities that are linked to climate change need scientific evaluation and must be curtailed before it is too late. This book contributes significantly in the field of sustainable natural resource management linked to climate change. Up to date research findings from developing and developed countries like India, Indonesia, Japan, Malaysia, Sri Lanka and the USA have been presented through selected case studies covering different thematic areas. The book has been organised into six major themes of sustainable natural resource management, determinants of forest productivity, agriculture and climate change, water resource management and riverine health, climate change threat on natural resources, and linkages between natural resources and biotic-abiotic stressors to develop the concept and to present the findings in a way that is useful for a wide range of readers. While the range of applications and innovative techniques is constantly increasing, this book provides a summary of findings to provide the updated information. This book will be of interest to researchers and practitioners in the field of environmental sciences, remote sensing, geographical information system, meteorology, sociology and policy studies related to natural resource management and climate change.
Download or read book Remote Sensing of Snow and Its Applications written by Ali Nadir Arslan and published by MDPI. This book was released on 2021-03-17 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reprint book of the “Remote Sensing of Snow and Its Applications” Special Issue provides recent studies on all aspects of remote sensing of snow, from retrieving the data to the application. These studies mainly address the following: (a) New opportunities (Copernicus Sentinels) and emerging remote sensing methods, (b) use of snow data in modeling, and (c) characterization of snowpack.
Download or read book Comprehensive Remote Sensing written by Shunlin Liang and published by Elsevier. This book was released on 2017-11-08 with total page 3183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Remote Sensing, Nine Volume Set covers all aspects of the topic, with each volume edited by well-known scientists and contributed to by frontier researchers. It is a comprehensive resource that will benefit both students and researchers who want to further their understanding in this discipline. The field of remote sensing has quadrupled in size in the past two decades, and increasingly draws in individuals working in a diverse set of disciplines ranging from geographers, oceanographers, and meteorologists, to physicists and computer scientists. Researchers from a variety of backgrounds are now accessing remote sensing data, creating an urgent need for a one-stop reference work that can comprehensively document the development of remote sensing, from the basic principles, modeling and practical algorithms, to various applications. Fully comprehensive coverage of this rapidly growing discipline, giving readers a detailed overview of all aspects of Remote Sensing principles and applications Contains ‘Layered content’, with each article beginning with the basics and then moving on to more complex concepts Ideal for advanced undergraduates and academic researchers Includes case studies that illustrate the practical application of remote sensing principles, further enhancing understanding
Download or read book Advanced Remote Sensing written by Shunlin Liang and published by Academic Press. This book was released on 2019-11-23 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Remote Sensing: Terrestrial Information Extraction and Applications, Second Edition, is a thoroughly updated application-based reference that provides a single source on the mathematical concepts necessary for remote sensing data gathering and assimilation. It presents state-of-the-art techniques for estimating land surface variables from a variety of data types, including optical sensors like RADAR and LIDAR. The book provides scientists in a number of different fields, including geography, geophysics, geology, atmospheric science, environmental science, planetary science and ecology with access to critically-important data extraction techniques and their virtually unlimited applications. While rigorous enough for the most experienced of scientists, the techniques presented are well designed and integrated, making the book’s content intuitive and practical in its implementation. Provides a comprehensive overview of many practical methods and algorithms Offers descriptions of the principles and procedures of the state-of-the-art in remote sensing Includes real-world case studies and end-of-chapter exercises Contains thoroughly revised chapters, newly developed applications and updated examples
Download or read book Estimation of Snow Depth and Snow Water Equivalent Using Passive Microwave Radiation Data written by Andrew Tait and published by . This book was released on 1996 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Snow Properties Retrieval Using Passive Microwave Observations written by Nastaran Saberi and published by . This book was released on 2019 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seasonal snow cover, the second-largest component of the cryosphere, is crucial in controlling the climate system, through its important role in modifying Earth's albedo. The temporal variability of snow extent and its physical properties in the seasonal cycle also make up a significant element to the cryospheric energy balance. Thus, seasonal snowcover should be monitored not only for its climatological impacts but also for its rolein the surface-water supply, ground-water recharge, and its insolation properties at local scales. Snowpack physical properties strongly influence the emissions from the substratum, making feasible snow property retrieval by means of the surface brightness temperature observed by passive microwave sensors. Depending on the observing spatial resolution, the time series records of daily snow coverage and a snowpacks most-critical properties such as the snow depth and snow water equivalent (SWE) could be helpful in applications ranging from modeling snow variations in a small catchment to global climatologic studies. However, the challenge of including spaceborne snow water equivalent (SWE) products in operational hydrological and hydroclimate modeling applications is very demanding with limited uptake by these systems. Various causes have been attributed to this lack of up-take but most stem from insufficient SWE accuracy. The root causes of this challenge includes the coarse spatial resolution of passive microwave (PM) observations that observe highly aggregated snowpack properties at the spaceborne scale, and inadequacies during the retrieval process that are caused by uncertainties with the forward emission modeling of snow and challenges to find robust parameterizations of the models. While the spatial resolution problem is largely in the realm of engineering design and constrained by physical restrictions, a better understanding of the whole range of retrieval methodologies can provide the clarity needed to move the thinking forward in this important field. Following a review on snow depth and SWE retrieval methods using passive microwave remote sensing observations, this research employs a forward emission model to simulate snowpacks emission and compare the results to the PM airborne observations. Airborne radiometer observations coordinated with ground-based in-situ snow measurements were acquired in the Canadian high Arctic near Eureka, NT, in April 2011. The observed brightness temperatures (Tb) at 37 GHz from typical moderate density dry snow in mid-latitudes decreases with increasing snow water equivalent (SWE) due to the volume scattering of the ground emissions by the overlying snow. At a certain point, however, as SWE increases, the emission from the snowpack offsets the scattering of the sub-nivean emission. In tundra snow, the Tb slope reversal occurs at shallower snow thicknesses. While it has been postulated that the inflection point in the seasonal time series of observed Tb V 37 GHz of tundra snow is controlled by the formation of a thick wind slab layer, the simulation of this effect has yet to be confirmed. Therefore, the Dense Media Radiative Transfer Theory forMulti Layered (DMRT-ML) snowpack is used to predict the passive microwave response from airborne observations over shallow, dense, slab-layered tundra snow. The DMRT-ML was parameterized with the in-situ snow measurements using a two-layer snowpack and run in two configurations: a depth hoar and a wind slab dominated pack. Snow depth retrieval from passive microwave observations without a-priori information is a highly underdetermined system. An accurate estimate of snow depth necessitates a-priori information of snowpack properties, such as grain size, density, physical temperature and stratigraphy, and, very importantly, a minimization of this a prior information requirement. In previous studies, a Bayesian Algorithm for Snow Water Equivalent (SWE) Estimation (BASE) have been developed, which uses the Monte Carlo Markov Chain (MCMC) method to estimate SWE for taiga and alpine snow from 4-frequency ground-based radiometer Tb. In our study, BASE is used in tundra snow for datasets of 464 footprints inthe Eureka region coupled with airborne passive microwave observations-the same fieldstudy that forward modelling was evaluated. The algorithm searches optimum posterior probability distribution of snow properties using a cost function between physically based emission simulations and Tb observations. A two-layer snowpack based on local snow cover knowledge is assumed to simulate emission using the Dense Media Radiative Transfer-Multi Layered (DMRT-ML) model. Overall, the results of this thesis reinforce the applicability of a physics-based emission model in SWE retrievals. This research highlights the necessity to consider the two-part emission characteristics of a slab-dominated tundra snowpack and suggests performing inversion in a Bayesian framework.
Download or read book Microwave Remote Sensing of Snowpacks written by William H. Stiles and published by . This book was released on 1980 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing of Snow and Ice written by Albert Rango and published by . This book was released on 1979 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Active and Passive Microwave Response to Snow Parameters written by Fawwaz Tayssir Ulaby and published by . This book was released on 1978 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compendium of Meteorology written by Horace R. Byers and published by . This book was released on 1952 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microwave Remote Sensing of Snowpack Properties written by and published by . This book was released on 1980 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Assesses use of microwave remote sensing to determine snow depth and water content. Includes 14 papers and transcription of final discussion session. Proceedings of workshop sponsored by NASA and held at Fort Collins, Colorado, May 20-22, 1980.
Download or read book Thermal Microwave Radiation written by Institution of Engineering and Technology and published by IET. This book was released on 2006-05-19 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combines theoretical concepts with experimental results on thermal microwave radiation to increase the understanding of the complex nature of terrestrial media. Emphasising on radiative transfer models, this book covers the terrestrial aspects, from clear to cloudy atmosphere, precipitation, ocean and land surfaces, vegetation, snow and ice.
