Estimation of Tropospheric Zenith Delay and Gradients
نویسندگان
چکیده
We have analyzed data from an experiment over the Madrid (Spain) area obtained from 5 GPS receivers and 3 Water Vapor Radiometers (WVR), in order to compare their retrievals of Tropospheric Slant Delays. For this purpose we have tted a simple gradient model to both types of data, using a Kalman lter to account for the temporal variability of the zenith and gradient parameters. We show that the retrieved gradients with the two instruments are compatible, thus suggesting that the derived slant delays can be useful for tomographic analysis. We compare the estimates of ZWD obtained with the GIPSY and the Bernese software packages. Finally, we compare the estimated gradients with those obtained with HIRLAM, a Numerical Weather Prediction model.
منابع مشابه
Accuracy Improvement of Tropospheric Delay Interpolation in RTK Networks
The effect of troposphere on the signals emitted from global navigation satellite system (GNSS) satellites, appears as an extra delay in the measurement of the signal traveling from the satellite to receiver. This delay depends on the temperature, pressure, humidity as well as the transmitter and receiver antennas location. In GNSS positioning, tropospheric delay effects on accuracy of differen...
متن کاملInvestigation of MODIS mission capability in tropospheric delay estimation for precise point positioning
Tropospheric delay is always considered as one of the factors limiting the accuracy of GPS. In this paper, the three-dimensional ray tracing technique is proposed to calculate the tropospheric delay. The ability of the MODIS mission to calculate the tropospheric delay is also examined. For this purpose, an area in central Europe was selected and a MODIS acquisition on 2008/08/01 was studied. In...
متن کاملInvestigations into the Estimation of Tropospheric Delay and Wet Refractivity Using GPS Measurements
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...
متن کاملAnalysing the Zenith Tropospheric Delay Estimates in On-line Precise Point Positioning (PPP) Services and PPP Software Packages
As Global Navigation Satellite System (GNSS) signals travel through the troposphere, a tropospheric delay occurs due to a change in the refractive index of the medium. The Precise Point Positioning (PPP) technique can achieve centimeter/millimeter positioning accuracy with only one GNSS receiver. The Zenith Tropospheric Delay (ZTD) is estimated alongside with the position unknowns in PPP. Estim...
متن کاملApplication of ray-traced tropospheric slant delays to geodetic VLBI analysis
The correction of tropospheric influences via socalled path delays is critical for the analysis of observations from space geodetic techniques like the very long baseline interferometry (VLBI). In standard VLBI analysis, the a priori slant path delays are determined using the concept of zenith delays, mapping functions and gradients. The a priori use of ray-traced delays, i.e., tropospheric sla...
متن کامل