This paper examines whether the radio occultation (RO) measurements of the tropopause region are able to improve radiometric tropospheric profile retrievals, as represented by the ATOVS (Advanced TIROS Operational Vertical Sounder) temperature and humidity soundings from the NOAA16 (National Oceanic and Atmospheric Administration) satellite. First, a simulation study is presented wherein a stat...

Fine structures in the vertical gradient of the electron density have been retrieved by means of analysis of the amplitude of radio occultation (RO) data in sporadic E-layers (heights interval 85-110 km). Maximum values of the positive gradients 45⋅10, 48⋅10, 25⋅10, 29⋅10 [mkm] are located at levels 92, 105 km (GPS/MET event 0393) and 93.5, 100 km (GPS/MET event 0583). Variations in the vertica...

This paper presents a radiopropagation algorithm based on Ray Tracing (RT) technique that combines modified multipath model for constant refractivity gradient profiles and the Uniform Theory of Diffraction (UTD). A novel formulation is proposed by authors calculation ground-reflection analysis ray paths depending atmospheric refractivity. The introduced herein was evaluated in mixed scenario tw...

Spatially localized refractivity variations, mainly due to water vapor, are a major source of error in high-precision positioning techniques such as GPS and SAR interferometry. Refractivity induced delay variations can be misinterpreted as, e.g., crustal deformation signals or positioning biases. In this study, signal delay estimates based on SAR observations and simultaneous GPS time series ar...

stronomical observations near the horizon have historically been made for naval navigation and for determining the time of sunset. Recent applications include near-horizon daytime scene simulation to support infrared search and track and infrared seeker studies. The ray path of the setting or rising Sun can be highly distorted near the horizon, and it is seldom rectilinear. An accurate model of...

We present a speciic method and its software implementation to determine the refractive index (n) of various gases, analysing the interferometric data of a pressure tunable Fabry-Perot interferometer from visible to VUV region. The principal idea of this method is to apply the Discrete Fourier Transform (DFT) on the data of the light intensity as a function of the gas pressure, in order to dete...

The electronic, hydrophobic and global reactivity parameters of modeled 28 different 5,8-quinolinequinone derivatives have been calculated using DFT (B3LYP)/6-31G(d,p) method basis set. molecular descriptors are chosen polarizability, dipole moment, frontier orbital energy, volume, ionization potential, electron affinity, electronegativity, hardness, softness, electrophilic index, molar refract...