Wavelength correction of refractivity variation measurements

The Refractivity of Air

The air density equation of Jones, Edlen's dispersion formula for standard air, and Edlen's empiricallyderived expressions for the effects of CO 2 abundance and water vapor partial pressure on refractivity have been combined into a simplified equation for the refractivity of air, and estimates have been made of uncertainties in calculated refractivity. Under ambient conditions typical of metrol...

The Refractivity of Protein Solutions

Use of GPS Phase Measurements to Improve Vertical Refractivity Profiles in the Boundary Layer

The primary scientific objective of this research is to develop GPS sounding techniques for ground based atmospheric profiling. Atmospheric profiling with GPS from space has been demonstrated (i.e. Ware et al. 1996, Rocken et al., 1997). Ground based GPS receivers have been used to determine integrated atmospheric water vapor above a site (i.e. Rocken et al., 1993), and along the ray paths to G...

Precision Length Measurements by Multi-Wavelength Interferometry

Three different applications of multi-wavelength interferometry are reviewed which have been developed at PTB. They demonstrate the high precision achievable by this technique on multiple scales, from absolute geodetic distances up to 10 m, over prismatic bodies, e.g. gauge blocks, in the sub-meter regime, down to the microscopic roughness of surfaces.

Tunable optical tweezers for wavelength-dependent measurements.

Optical trapping forces depend on the difference between the trap wavelength and the extinction resonances of trapped particles. This leads to a wavelength-dependent trapping force, which should allow for the optimization of optical tweezers systems, simply by choosing the best trapping wavelength for a given application. Here we present an optical tweezer system with wavelength tunability, for...