Download or read book A Correlation based Approach to Modeling Interferometric Radar Observations of the Greenland Ice Sheet written by E. Weber Hoen and published by . This book was released on 2001 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Interferometric synthetic aperture radar (InSAR) phase observations have greatly increased our understanding of the topography and motion of ice sheets, but yield little information on the sub-surface structure, a needed description for mass-balance estimates. Inversion of a diffuse volume scatter model shows that InSAR correlation values, p, can be related to radiowave penetration depths, d, which depend on characteristics of the snow/ice volume. Application to European Research Satellite (ERS) images (VV, 5.6 cm, 23 ̊incidence angle) of the Greenland ice sheet imply C-band d of 0 m along the rocky coast, 10-20 m in the bare ice zone, and 20-35 m in the percolation zone and dry snow zone, consistent with in situ results. Moreover, volume scattering reduces the ERS critical baseline from about 1100 m to 300 m. Correlation and backscatter power (ơ0) observations can be combined for further understanding of the snow/ice volume. In particular, p and ơ0 data of 15 km-long, 50 m-high topographic undulations in the dry snow zone arc minimum on the windward side and maximum on the lee side, with 1 to 3 dB variation typical. These spatial variations in the scattering medium appear to follow from differences in snow accumulation due to prevailing winds. Assuming that snow-grains are the dominant source of backscatter, the classical independent-scatterer model is physically implausible at firn densities; a second-order dense-medium radiative transfer model also is unable to explain both the observed d and ơ0. A modified Born approach provides a better match to ơ0 and p separately, but leads to different grain size solutions for each measurement type. A buried layer model based on the incoherent addition of echoes from hoar layer interfaces, in which scattering from a single layer is derived from small-perturbation methods, reconciles the ERS ơ0 and p data, with variations in hoar layer spacing of 12-17 cm providing the needed structural fluctuations for the observed range of ơ0 and p. Translation of layer spacing into accumulation rates predicts a 40% variability in accumulation rate from the windward to lee side and, more importantly, addresses high-resolution mapping of continental accumulation rates"--Leaves iv-v.

Download or read book Estimating Snow Accumulation from InSAR Correlation Observations written by Shadi Oveisgharan and published by . This book was released on 2007 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Snow accumulation in remote regions such as Greenland and Antarctica is a key factor for estimating Earth's ice mass balance. In situ data are sparse, hence it is useful to derive snow accumulation from remote sensing observations, such as from microwave thermal emission and from radar brightness. These data are usually interpreted using electromagnetic models in which volume scattering is the dominant mechanism. The main limitation of this approach is that microwave brightness is not well-related to backscatter if the ice sheet is layered. Because larger grain size and thicker annual layers both increase radar image brightness, the first corresponding to lower accumulation rate and the second to higher accumulation rate, models of radar brightness alone cannot accurately reflect accumulation. Consideration of interferometric radar correlation measurements also can resolve this ambiguity. Here we introduce an ice scattering model that relates InSAR correlation and radar brightness to both ice grain size and hoar layer spacing in the dry snow zone of Greenland. We use this model and ERS satellite radar observations to derive several parameters related to snow accumulation rates in a small area in the dry snow zone. These parameters show agreement with four in situ core accumulation rate measurements in this area, while models using only radar brightness data do not match the observed variation in accumulation rates.

Download or read book GIScience Remote Sensing written by and published by . This book was released on 2008 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IEEE International Geoscience and Remote Sensing Symposium Proceedings written by and published by . This book was released on 2003 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annual Commencement written by Stanford University and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IGARSS 2003 written by and published by . This book was released on 2003 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book L band InSAR Estimates of Greenland Ice Sheet Accumulation Rates written by Albert C. Chen and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Greenland Ice Sheet contains nearly 3 million cubic kilometers of glacial ice. Were the ice to completely melt, that would cause the sea level to rise about 7 meters. Each year, the ice sheet gains ice from snowfall and loses ice through iceberg calving and other ablation mechanisms. Thus assessing the ice sheet's mass balance (annual net gain/loss of ice) requires accurate spatial mapping of accumulation rates (mean annual snowfall). In this thesis, we examine how recent satellite radar remote sensing data can be used to supplement in-situ accumulation rate estimates in the inner regions of the Greenland Ice Sheet. We present a method using interferometric synthetic aperture radar (InSAR) data to obtain estimates of snow accumulation in Greenland. InSAR is a technique that provides images of the Earth from radar data collected by a spacecraft. We show that the second-order phase statistics (coherence) of InSAR images is related to subsurface structure, which, in the inner dry-snow zone of the Greenland ice sheet, is related to accumulation rate. We have implemented software to form and geocode InSAR images of Greenland and correct for ionospheric inhomogeneity, which has limited the accuracy of longer-wavelength measurements of the Earth's polar regions. We developed a model to relate accumulation rate to InSAR measurements. By inverting the model we obtain estimates of Greenland ice sheet accumulation rates. We show a comparison of our results with in-situ measurements over a 1,400 km strip spanning the entire dry-snow zone, and demonstrate that they follow the in-situ measurements more accurately than state-of-the-art results derived from radar amplitude measurements alone.

Download or read book Polar Environments and Global Change written by Roger G. Barry and published by Cambridge University Press. This book was released on 2018-08-09 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surveys atmospheric, oceanic and cryospheric processes, present and past conditions, and changes in polar environments.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book ICESat written by H. Jay Zwally and published by . This book was released on 2002 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polarimetric Synthetic Aperture Radar written by Irena Hajnsek and published by Springer Nature. This book was released on 2021-03-24 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book focuses on the practical application of electromagnetic polarimetry principles in Earth remote sensing with an educational purpose. In the last decade, the operations from fully polarimetric synthetic aperture radar such as the Japanese ALOS/PalSAR, the Canadian Radarsat-2 and the German TerraSAR-X and their easy data access for scientific use have developed further the research and data applications at L,C and X band. As a consequence, the wider distribution of polarimetric data sets across the remote sensing community boosted activity and development in polarimetric SAR applications, also in view of future missions. Numerous experiments with real data from spaceborne platforms are shown, with the aim of giving an up-to-date and complete treatment of the unique benefits of fully polarimetric synthetic aperture radar data in five different domains: forest, agriculture, cryosphere, urban and oceans.

Download or read book Encyclopedia of Snow Ice and Glaciers written by Vijay P. Singh and published by Springer Science & Business Media. This book was released on 2011-06-29 with total page 1301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The earth’s cryosphere, which includes snow, glaciers, ice caps, ice sheets, ice shelves, sea ice, river and lake ice, and permafrost, contains about 75% of the earth’s fresh water. It exists at almost all latitudes, from the tropics to the poles, and plays a vital role in controlling the global climate system. It also provides direct visible evidence of the effect of climate change, and, therefore, requires proper understanding of its complex dynamics. This encyclopedia mainly focuses on the various aspects of snow, ice and glaciers, but also covers other cryospheric branches, and provides up-to-date information and basic concepts on relevant topics. It includes alphabetically arranged and professionally written, comprehensive and authoritative academic articles by well-known international experts in individual fields. The encyclopedia contains a broad spectrum of topics, ranging from the atmospheric processes responsible for snow formation; transformation of snow to ice and changes in their properties; classification of ice and glaciers and their worldwide distribution; glaciation and ice ages; glacier dynamics; glacier surface and subsurface characteristics; geomorphic processes and landscape formation; hydrology and sedimentary systems; permafrost degradation; hazards caused by cryospheric changes; and trends of glacier retreat on the global scale along with the impact of climate change. This book can serve as a source of reference at the undergraduate and graduate level and help to better understand snow, ice and glaciers. It will also be an indispensable tool containing specialized literature for geologists, geographers, climatologists, hydrologists, and water resources engineers; as well as for those who are engaged in the practice of agricultural and civil engineering, earth sciences, environmental sciences and engineering, ecosystem management, and other relevant subjects.

Download or read book Computer Processing of Remotely Sensed Images written by Paul M. Mather and published by John Wiley & Sons. This book was released on 2005-12-13 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remotely-sensed images of the Earth's surface provide a valuable source of information about the geographical distribution and properties of natural and cultural features. This fully revised and updated edition of a highly regarded textbook deals with the mechanics of processing remotely-senses images. Presented in an accessible manner, the book covers a wide range of image processing and pattern recognition techniques. Features include: New topics on LiDAR data processing, SAR interferometry, the analysis of imaging spectrometer image sets and the use of the wavelet transform. An accompanying CD-ROM with: updated MIPS software, including modules for standard procedures such as image display, filtering, image transforms, graph plotting, import of data from a range of sensors. A set of exercises, including data sets, illustrating the application of discussed methods using the MIPS software. An extensive list of WWW resources including colour illustrations for easy download. For further information, including exercises and latest software information visit the Author's Website at: http://homepage.ntlworld.com/paul.mather/ComputerProcessing3/

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quaternary Glaciation History and Glaciology of Jakobshavn Isbrae and the Disko Bugt Region West Greenland written by Anker Weidick and published by . This book was released on 2007 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thriving on Our Changing Planet A Decadal Strategy for Earth Observation from Space written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-06-18 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space (National Academies Press, 2018) provides detailed guidance on how relevant federal agencies can ensure that the United States receives the maximum benefit from its investments in Earth observations from space, while operating within realistic cost constraints. This short booklet, designed to be accessible to the general public, provides a summary of the key ideas and recommendations from the full decadal survey report.

Download or read book Sea Ice Analysis and Forecasting written by Tom Carrieres and published by Cambridge University Press. This book was released on 2017-10-05 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive overview of the science involved in automated prediction of sea ice, for sea ice analysts, researchers, and professionals.