Contrary to several recent studies, we find strong evidence in the Sloan Digital Sky Survey for the “Holmberg Effect”, the tendency for the satellites of isolated late-type galaxies to align with the minor axis of the galactic disc. In the case of isolated earlytypes, we find that satellites tend to align with the major axis of the galaxy. Using mock catalogues generated from cosmological N -bo...

Sampling retrievals of high-accuracy first-moment statistics constitute a central concern for climate research. Considered here is the important case of brightness temperature retrievals from a selection of possible orbits. Three-hourly global satellite brightness temperature data are used to predict the sampling error of monthly to annual mean brightness temperature retrieved by one or more sa...

Repetitive DNA are DNA sequences that are repeated multiple times in the genome and normally considered nonfunctional. Several studies predict that the rapid evolution of chromosome-specific satellites led to hybrid incompatibilities and speciation. Interestingly, in Drosophila, the X and dot chromosomes share a unique and noteworthy property: They are identified by chromosome-specific binding ...

the gravity recovery and climate experiment (grace), twin satellites launched in march 2002, are making detailed measurements of the earth's gravity field. it will yield discoveries about gravity and the earth's natural systems. different sensors and instruments have been placed in the grace satellites to fulfill the primary scientific objective of the mission in mapping the earth’s g...

With non-GEO constellations the primary means of counteracting the shadowing and the blockage effects is through the use of the satellite diversity, i.e. multiple satellites in the constellation are simultaneously visible to user. The probability system availability is improved by increasing the probability at least one satellite is in clear Line Of Sight. In the selection diversity (SD) scheme...

The incorporation of multiple constellations into satellite based augmentation systems (SBAS) may lead to cases where there are more corrected satellites in view than a receiver has tracking channels. This paper addresses two related topics: identifying the most important satellites to track in order to provide availability; and identifying a recommended number of channels. Previously, the SBAS...

N O V E M B E R / D E C E M B E R 2 0 1 6 www.insidegnss.com The advent of multiple constellations provides the opportunity to eliminate geometry weakness as a source of satellite-based augmentation system (SBAS) unavailability. GPS users occasionally encounter areas where an insufficient density of satellites exists to support all desired operations. This most often occurs when a primary slot ...

Real-time kinematic – global navigation satellite systems (RTK-GNSS) provide positions with centimeter error; however, performance in urban area is degraded by multipath error. Common approaches to mitigate are selection based on SNR values or classification of LOS and NLOS signals. In this study, carrier phase lock indicator elapsed epoch when it invalid was used select satellites. Car experim...

In attitude determination using GPS, the accuracy of results is influenced directly by the satellite selection of the differenced observations. Based on the information of satellites, such as elevation, azimuth and signal to noise ratio, we apply a weighted selection method to obtain the satellite combination used in attitude determination. This method also considered the quality of satellite s...