Radio wave propagation on low-altitude paths over the ocean above 2GHz is significantly affected by negative refractivity gradients in the atmospheric surface layer, which form what is often referred to as an evaporation duct (ED). Refractivity from clutter (RFC) is an inversion approach for the estimation of the refractivity profile from radar clutter, and RFC-ED refers to its implementation f...

The Transportable Atmospheric RAdar (TARA) is an Sband polarimetric FM-CW profiler that is located at the meteorological site, Cabauw, the Netherlands (Russchenberg et al. 2005). At this wavelength (λ=9.1 cm), the wind tracers are raindrops, water cloud droplets, ice crystals and snowflakes. These particles are ranging in sizes from 0.01 mm to 10 mm. Clear air scattering, which consists of refl...

[1] Refractivity from clutter (RFC) retrieves the radio frequency refractive conditions along a propagation path by inverting the measured radar sea clutter return. In this paper, a real-time RFC technique is proposed called ‘‘Improved Best Fit’’ (IBF). It is based on finding the environment with best fit to one of many precomputed, modeled radar returns for different environments in a database...

Validation studies of current GPS radio occultation experiments using meteorological analyses consistently report on a negative refractivity bias in the lower troposphere. It is shown that refractivity profiles obtained from Doppler-inverted bending angle profiles not only deviate significantly within zones of multipath propagation but also depend on the selected end point of the occultation si...

Refractive indices of various H(2)SO(4)-H(2)O, HNO(3)-H(2)O, and H(2)SO(4)-HNO(3)-H(2)O solutions were measured at four wavelengths in the visible (351.0, 533.5, 632.9, and 782.6 nm) over a temperature range from 30 to -60 degrees C. The temperature dependence has been determined for the first time to the authors' knowledge. This dependence is of importance for applications to atmospheric aeros...

Radio wave propagation on low-altitude paths over the ocean above 2 GHz is significantly affected by negative refractivity gradients in the atmospheric surface layer (ASL) which form what is often referred to as an evaporation duct (ED). Refractivity from clutter (RFC) is an inversion approach for estimation of the refractivity profile from radar clutter, and RFC-ED refers to its implementation...

[1] This paper addresses the problem of estimating the lower atmospheric refractivity (M profile) under nonstandard propagation conditions frequently encountered in lowaltitude maritime radar applications. This is done by statistically estimating the duct strength (rangeand height-dependent atmospheric index of refraction) from the sea surface reflected radar clutter. These environmental statis...

The interrelation between retention factors of several L-amino acids and their physico-chemical and structural properties can be determined in chromatographic research. In this paper we describe a predictor for retention factors with various properties of the L-amino acids. Eighteen L-amino acids are included in this study, and retention factors are measured experimentally by RP-HPLC. Binding e...

InSAR signal delays due to the varying atmospheric refractivity are a potential data source to improve weather models [1]. Especially with the launch of the new Sentinel-1 satellites, which increases data coverage, latency and accessibility, it may become possible to operationalize the assimilation of differential integrated refractivity (DIR) values in numerical weather models. Although studie...

The primary scientific objective of this research is to develop GPS sounding techniques for ground based atmospheric refractivity sensing. Atmospheric profiling with GPS from space has been demonstrated (e.g. Rocken et al., 1997). Ground based receivers have been used to determine integrated atmospheric water vapor above a site, but profiling techniques with ground-based GPS observations are st...