The principal error source in the GPS technology is a delay experienced by the GPS signal in propagating through the electrically neutral atmosphere, usually referred to as a tropospheric delay. This delay is normally calculated in the zenith direction, and is referred to as a zenith tropospheric delay. The delay consists of a zenith hydrostatic delay, which can be modeled accurately using surf...

the density (d), speed of sound (u) and electrolytic conductivity (λ) for systems containing acetaminophen, ionic liquid {1-octyl-3-methyl imidazolium bromide, [omim] br} and water have been measured at t = 293.15-308.15 k. the measured data have been applied to calculate, standard partial molar volume ( ), hepler’s constant , apparent molar isentropic compressibility (kφ), transfer volume ( ),...

By measuring the refractivity and temperature of a gas, its pressure can be calculated from fundamental principles. The most sensitive instruments are currently based on Fabry–Perot cavities where laser is used to probe frequency cavity mode. However, for best accuracy, realization such systems requires exceptional mechanical stability. Gas modulation refractometry (GAMOR) has previously demons...

It is proposed to obtain information on atmospheric refractivity structure by measuring the angle of arrival (AoA) radio signals routinely broadcast commercial aircraft. The would be measured at hill-top sites using a simple two-element interferometer. Knowledge aircraft’s location (information conveniently contained within broadcasts) and AoA will enable bending calculated. As measurable only ...