The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
GeoGateway is a web-enabled map-based system for analysis, modeling, and response of geodetic imaging products for studying earthquakes and crustal deformation. The system provides a data product search and analysis gateway for scientific discovery, field use, and disaster response. To be effective users require data overlay and visualization, interactive analysis features, and data product download...
Digital shorelines obtained from old maps and photographs as well as more recent GPS surveys are used to study the developments in coastal geomorphic processes in relation to variations in climatic and oceanographic forcing factors in the Baltic Sea area. By the end of the 20th century, the postglacial isostatic land uplift is nearly balanced out by the sea level rise and storminess-related shore...
Precipitable Water Vapor (PWV) is a good source to monitor precipitation. It is defined by the amount of water vapor present in atmosphere. Traditionally, radiosondes and microwave radiometers were used to derive PWV. However, these devices have poor temporal resolutions and high operational costs. Therefore, GPS signal delay is now widely used for such purposes. The main aim of this paper is to study...
This research investigated the impact of Radio Occultation (RO) data assimilation on cyclone monitoring. The global positioning system (GPS) radio occultation limb sounding technique has appeared as an efficient global observing system. This technique cans provide good performance in all weather conditions and without calibration requirement. GPS RO data from the Constellation Observing System for...
Global Navigation Satellite System (GNSS) signals can be used as a kind of bistatic radar, with receivers opportunistically recording ground-reflected signals transmitted by the GNSS satellites themselves. The ground-reflected signals are sensitive to changes in surface permittivity, which for L-band is primarily a function of the moisture content of the surface. Here, we investigate the ability of...
Intertidal flats are productive and rapidly changing places. However, these places are facing many environmental challenges related to climate change and human-induced impacts. Topographic change due to sedimentation or erosion in intertidal flats can be the key indicator for recognizing these environmental changes. The intertidal flats usually have small topographic variations (less than 5m) and...
In this paper, the accuracy of TanDEM-X DEMs is evaluated for different terrains of India and is also compared with that of Cartosat-1 optical stereo DEMs. Using accurate GPS points as reference, TanDEM-X DEMs of Mumbai area with flat as well as low hilly terrain, Koyna area with high hilly terrain, rugged Himalayan terrain of Manali and Katerniaghat area with forest cover over flat terrain were evaluated...
Global Navigation Satellite Systems Reflectometry (GNSSR) is a sort of multi-static radar using navigation signals as signals of opportunity. Due to the large number of transmitting satellites multiple scattering points over the Earth's surface can be simultaneously tracked, which provides wide-swath and improved spatio-temporal sampling over current space-borne radar altimetry missions. The lack...
Soil moisture measurements are important for disciplines such as hydrology, climatology and agriculture. GNSS Reflectometry (GNSS-R) technique has been demonstrated to be an effective tool to sense soil moisture content (SMC). Besides airborne observations, great efforts have also been made concerning ground-based measurements. However, those methods are either based on too many hypotheses or depend...
Global Navigation Satellite Systems Reflectometry (GNSSR) is now being recognized as a powerfull tool for remote sensing. With the addition of new frequency bands and codes, it is possible to increase the resolution and accuracy of the measurements. GPS L5 and Galileo E5 bands are becoming popular because of the open codes, with wider bandwidths than the L1 band ones. However, these bands are shared...
The GNSS rEflectometry, Radio Occultation and Scatterometry onboard the International Space Station (GEROS-ISS) is an innovative experiment for climate research, proposed in 2011 within a call of the European Space Agency (ESA) for installation at the ISS. This international proposal was the only one selected for further studies by ESA out of ∼25 submitted ones. In this work, an updated assessment...
Up to now, it is still difficult to obtain reliable precursors and to understand the detail and nature of earthquakes from traditional technique observations. Nowadays, the ionospheric total electron content (TEC) from ground-based global navigation satellite systems (GNSS) and space-borne GNSS Radio Occultation can be used to investigate the seismo-ionospheric disturbances, which may provide insights...
The Tropopause in Tibet has complex and variable characteristics due to its harsh natural conditions, while it is hard to monitor the tropopause in Tibet from traditional techniques. Nowadays, the high resolution data from GPS Radio Occultation provide a unique opportunity to monitor the tropopause variation, particularly over Tibet. In this paper, the high resolution cold-point tropopause (CPT) in...
The orbit of TerraSAR-X is strictly controlled and well known. Based on this information, a very high absolute accuracy in geo-locating TerraSAR-X data is possible and has been demonstrated before. In this manuscript, we present an experimental validation of this, demonstrating the very high level of accuracy achievable using only the atmospheric phase delay information provided in the header files...
The geodetic-quality GPS receivers can be used for geophysical parameters retrieval, i.e. soil moisture, vegetation growth and snow depth, and it is called GPS-Interferometric Reflectometry (GPS-IR) remote sensing. In this paper, to detect the near surface soil freeze-thaw process using GPS-IR is evaluated for the first time. When the soil changes from frozen state to thawn state, the corresponding...
Range accuracy of synthetic aperture radar using modern satellites has been proven in centimeter-range after consideration of geodynamic, atmospheric effects and systematic errors; it is so-called Imaging Geodesy technique. Based on this technique, we have proposed the next-generation of Synthetic Aperture Radar (SAR) products and developed operational software SAR Geodesy Processor in the previous...
In this research, different satellite observation data were assimilated into the Weather Research and Forecasting Model (WRF) by using Three-dimensional Variational Data Assimilation System (3DVAR) and its impact on heavy rainfall forecasts was analyzed. The assimilation data include microwave radiance observations from the Advanced Microwave Sounding Unit-A (AMSU-A) and Global Positioning System...
TanDEM-X (TerraSAR-X add-on for Digitial Elevation Measurement), a German SAR satellite, was launched in June 2010. Since 2012, TanDEM-X mission has provided the most detailed global DEM with unprecedented accuracy. Also, they carried out various experimental mode including long baseline XTI (cross track interferometry). Despite their progressive instrument calibration and high accurate orbit determination,...
InSAR has been widely used in monitoring land subsidence over large area. However, many factors in InSAR processing, such as decorrelation error, atmosphere error, height error and thermal noise limit the accuracy of InSAR measurements. The height error over urban area is particularly the most difficult issue in TerraSAR-X data processing for its shorter wavelength and higher spatial resolution. We...
The water vapor plays an important role on the microwave propagation. Plenty of methods to reduce its effects in the differential InSAR technique have been put forward, such as using MERIS, MODIS, GPS and the weather models. In order to analyze the water vapor effects quantitatively, we selected several time-series related Envisat ASAR images with their corresponding synchronous MERIS Full Resolution...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.