Together, the Global Positioning System (GPS) and the Wide Area Augmentation System (WAAS) can guide aircraft down to 200 ft above the runway. This approach procedure is referred to as Localizer Performance with Vertical guidance (LPV)-200. Approach guidance using GPS and WAAS has many advantages over traditional precision approach guidance using the Instrument Landing System (ILS) and the numb...

The half-life of 87Rb was measured by a liquid scintillation method according to the efficiency tracing method. The measuring sample of rubidium chloride was dissolved in a scintillation cocktail of Insta-gel, and the rubidium was determined by gravimetry as tetraphenylborate. The result was (5.56 +/- 0.025) x 10(10) years.

Refractive scintillation effects in pulsars are powerful techniques for discriminating between different models proposed for the electron density fluctuation spectrum in the interstellar medium. Data from our long-term scintillation study of eighteen pulsars in the dispersion measure range 3−35 pc cm (Paper I) are used to investigate two important observable effects of refractive scintillation,...

The measurement of the strength of atmospheric optical turbulence by use of a modified generalized SCIDAR (scintillation detection and ranging) inversion technique is outlined and demonstrated. This new method for normalizing and inverting scintillation covariances incorporates the geometry specific to generalized SCIDAR. Examples of profiles from two astronomical observation sites are presented.

This paper introduces Ordinary Kriging as a method for the creation of maps of scintillation indices S4 and σφ which could be used to provide the user information on the accuracy of specific receiver-satellite links. Sufficiently accurate scintillation maps, also providing an er‐ ror estimate of the map values, could ultimately lead to their direct implementation in the positioning’s stochastic...

Multistation observations of ionosphere scintillation at VHF (250 MHz) and GNSS L1 frequency from three locations – (i) Bokkhali (BOK) (geographic 21.6 N, 88.2 E, dip 31.48), (ii) Raja Peary Mohan College Centre (RPMC) (geographic 22.66 N, 88.4 E, dip 33.5) and (iii) Krishnath College Centre (KNC), Berhampore (geographic 24.1 N, 88.3 E, dip 35.9) – at∼ 1 latitudinal separations near the norther...

We consider detection of high-energy photons in PET using thick scintillation crystals. Parallax effect and multiple Compton interactions such crystals significantly reduce the accuracy of conventional detection methods. In order to estimate the photon line of flight based on photomultiplier responses, we use asymptotically optimal nonlinear techniques, implemented by feed-forward and radial ba...

A small number of quasars exhibit interstellar scintillation on time-scales less than an hour; their scintillation patterns are all known to be anisotropic. Here we consider a totally anisotropic model in which the scintillation pattern is effectively one-dimensional. For the persistent rapid scintillators J1819+3845 and PKS1257−326 we show that this model offers a good description of the two-s...