The probability distribution of local relative humidity R in the free troposphere is explored by comparing a simple theoretical calculation with observations from the Global Positioning System (GPS) and the Microwave Limb Sounder (MLS). The calculation is based on a parcel of air that conserves its composition during diabatic subsidence, until it is resaturated by randomly entering a convective...

Dioscorea species or commonly named as yam is reported to be one of the major food sources worldwide. This ethnobotanical study was conducted to document local knowledge and potentials of DioscoreahispidaDennst. and to investigate and record its distribution in three districts of Terengganu. Information was gathered from 23 villagers from three districts of Besut, Marang and Setiu by using semi...

For decades the global positioning system (GPS) has been the only space geodetic technique routinely used for inter-continental frequency transfer applications. In the past very long baseline interferometry (VLBI) has also been considered for this purpose and the method’s capabilities were studied several times. However, compared to GPS current VLBI technology only provides few observations per...

Tropospheric tomography using data from local networks of Global Positioning System (GPS) receivers is producing encouraging spatio-temporal representations of the wet refractivity field. In this work we present the results from a small-scale geodetic experiment that we carried out at the Onsala Space Observatory. Seven GPS receivers distributed within a radius of 3 km from the center, were dep...

Monitoring of substation equipment performance and maintenance needs is typically met with test devices that are brought to a substation and data is collected manually. This paper introduces a new concept where this process is performed through an on-line data acquisition and processing solution. This is accomplished by utilizing substation automation systems for diagnostics and maintenance pur...

critical insights into processes of interest to science and society, from subsurface movements of magma; to changes in strain before, during, and after earthquakes; to the motion of ice sheets. Yet even today, vast portions of Earth remain infrequently monitored for deformation, or not monitored at all. And that dearth of information is despite intense efforts and such advances as the global po...

Over the last decade, the 1-sample-per-second kinematic Global Positioning System (GPS) has been used as a displacement sensor in earthquake observations and for structural health monitoring. Many researchers in both seismology and engineering have expressed the desire for higher-sample-rate (10-sample-per-second or higher) GPS data to acquire high-frequency displacement information. We perform...

In this paper, we analyze the code acquisition performance of a multicarrier direct-sequence spread spectrum (DS-SS) system in the presence of data modulation (i.e., no pilot) on multipath Rayleigh fading channels. The motivation of this analysis arises from the possibility of beneficially using multicarrier DS-SS in global positioning system (GPS) pseudolites, where unmodulated pilot is not av...

Ground-reflected global positioning system signals measured by a geodetic-quality GPS system can be used to infer temporal changes in near-surface soil moisture for the area surrounding the antenna. This technique, known as GPS-interferometric reflectometry, analyzes changes in the interference pattern of the direct and reflected signals, which are recorded in signal-to-noise ratio (SNR) data, ...

If a photo is worth a thousand words, is a geotagged photo worth even more? Recent advances in Global Positioning System (GPS) and digital camera technology have enabled photographers to add an additional layer of context to their images. By linking photographs to the location where they were taken, geotagged photographs can be seen as source of qualitative and quantitative information. For exa...