The complex morphology of large sand dunes of the world's great deserts have significant importance on conservation and climate change and hence are of interest to a wide variety of scientific and environmental applications including studies on aeolian processes, paleoclimate, civilian infrastructure management, and design of blown‐sand control systems. Scientific studies on dune formation and dynamics have been limited to desert margins due to inaccessibility of the desert interior by conventional surveying and mapping techniques. Thus, dune morphology in the deep desert interiors is not well studied and much about the driving forces controlling dune activity and dynamics are still poorly understood. We demonstrate the utility of space‐based observations to characterize dune morphology. Specifically, we used the Shuttle Radar Topography Mission (SRTM) C‐band data to investigate and compare morphologic attributes of dune fields of the Taklimakan and the Namib Deserts. Cross‐sectional amplitude roughness estimates have similar magnitude but stoss slopes are shallower in the Taklimakan Desert than in the Namib Desert. The high Height‐Width (H:W) ratio of 0.09 for the linear dunes in the Taklimakan Desert is indicative of its equilibrium with aeolian shear stress whereas the Namib Desert dunes are unstable. Multi‐resolution planimetric properties from SRTM Digital Elevation Model (DEM) using B‐spline wavelet decomposition reveal linear dunes in the Taklimakan Desert are superimposed on a dome‐like substrate whereas the linear dune in the Namib Desert are constructed on a knoll‐like submorphology. These long‐wavelength features, taken as paleotopography, may be a major controlling factor on wind patterns and dune sinuosity. We demonstrate the utility of ANFIS to assess seasonal dune changes in the Namib Desert using ICESat observations and SRTM. ANFIS is a data‐driven prediction scheme. Predicted topography along ICESat tracks have low rms of 3.5m, a 30% increase over SRTM accuracy. Seasonal track comparison from August 2003 to January 2005 shows that most changes to dune topography occur at crestal deformation of isolated dunes. The results show seasonal waning and waxing of dune crests.

The Atatürk Dam in Turkey, constructed on the Firat River, is one of the world’s largest rockfill embankment dams. It was built to harvest and conserve water and to serve crucial agricultural, social-economic, recreational, and other activities in the Harran region. In this study, geodetic techniques were exploited to assess possible deformations of the embankment structure and add insight on critical dam safety. The geodetic approach included differential, trigonometric, and global positioning system (GPS) leveling observation campaigns over a period of 6.5 years from May 2006 through November 2012. The geodetic control network included 32 reference points and approximately 200 object points located on the surface of the embankment structure. The primary object points were stable concrete platforms embedded on the compacted rock surface, whereas the secondary object points were mounted directly to the compacted rock. All object points were equipped with forced centering mechanisms to support eit...

Total electron content (TEC) estimates derived from Global Navigation Satellite System (GNSS) signal delays provide a rich source of information about the Earth's ionosphere. Networks of Global Positioning System (GPS) receivers data can be used to represent the ionosphere by a Global Ionospheric Map (GIM). Data input for GIMs is dual‐frequency GNSS‐only or a mixture of GNSS and altimetry observations. Parameterization of GNSS‐only GIMs approaches the ionosphere as a single‐layer model (SLM) to determine GPS TEC models over a region. Limitations in GNSS‐only GIM TEC are due largely to the nonhomogenous global distribution of GPS tracking stations with large data gaps over the oceans. The utility of slant GPS ionospheric‐induced path delays for high temporal resolution from a single‐station data rate offers better representation of TEC over a small region. A station‐based vertical TEC (TEC_V) approach modifies the traditional single‐layer model (SLM) GPS TEC method by introducing a zenith angle weighting (ZAW) filter to capture signal delays from mostly near‐zenith satellite passes. Comparison with GIMs shows the station‐dependent TEC (SD‐TEC) model exhibits robust performance under variable space weather conditions. The SD‐TEC model was applied to investigate ionospheric TEC variability during the geomagnetic storm event of 9 March 2012 at midlatitude station NJJJ located in New Jersey, USA. The high temporal resolution TEC results suggest TEC production and loss rate differences before, during, and after the storm.