The impact of the antenna phase center models on the coordinates in the EUREF Permanent Network

Abstract

Precise positioning using the signals of the Global Position System requires correcting the distance between the points of reception of the signal carrier phase and the antenna reference point. Sophisticated models to account for these phase errors are available and widely in use. These models are usually based on calibrations of several antennas of the same type to derive a mean model. There is also the possibility of applying individual correction models that are derived for one single antenna, since the individual antennas may still vary by a few millimeters. We prepared two sets of station position time series to understand the impact of using type mean or individual antenna correction models. At first, we estimated the station positions using the type mean model for the antenna corrections as it is provided by the IGS. Second, the same processing strategy was used, but this time with individual antenna correction models provided they were available. Then, based on these two solutions, we evaluated how different antenna corrections impact the network alignment and subsequently station coordinates. We showed that mixing two sources of antenna phase center corrections may influence the reference frame realization. However, this impact is very small and can be reduced by an appropriate selection of reference stations. Finally, we demonstrated that for some antennas, the application of type mean or individual antenna calibration models may cause a discrepancy in the position of over 10 mm for the horizontal and vertical component. However, for most of the antennas these offsets are below 2 mm for horizontal components and below 4 mm for vertical component. Thereby, for common antennas we confirmed the results obtained by others.

EPN-Repro2: A reference GNSS tropospheric data set over Europe

“…For these three specific hardware sets the individual calibrations are available at the EPN Central Bureau (ftp://epncb.oma.be/pub/station/general/epnc_08.atx). Switching between phase centre corrections from type mean to individual (or vice versa) causes a disagreement in the estimated up component of the stations, as was mentioned by Araszkiewicz and Voelksen (2017), and as a consequence in their ZTD time series. Depending on the antenna model, the offset at station KLOP in the up component (vertical displacement) is −5.2 ± 0.5, 8.7 ± 0.6 and 5.6 ± 0.8 mm with a corresponding offset in the ZTD of 0.2 ± 0.5, −1.5 ± 0.5, −1.4 ± 0.8 mm, respectively.…”

Impact of Using GPS L2 Receiver Antenna Corrections for the Galileo E5a Frequency on Position Estimates

“…It should be remembered here that antenna modeling impacts on all estimates, such as tropospheric delay or clocks. However, previously conducted studies on receiver antennas show that the greatest impact of using different PCCs is more visible in the height [ 23 ], and much less visible in the tropospheric parameters [ 34 , 35 ]. Therefore, in our study, we focused only on the coordinates.…”

“…An example is the calibrations performed by the University of Bonn, Institute of Geodesy and Geoinformation [ 20 ]. The compatibility between chamber calibrations and robot calibrations is on a millimeter level [ 18 ], and is constantly the subject of discussion and analysis [ 21 , 22 , 23 , 24 ].…”

Antenna phase center correction differences from robot and chamber calibrations: the case study LEIAR25

“…Noting the relationship between antenna models and differences between calibration results, they formulated recommendations for all relevant antennas. Araszkiewicz and Völksen (2017) compared type mean and individual antenna calibration models and demonstrated that for some antennas, the discrepancy in the position resulting from the utilized calibration model can reach 10 mm in both horizontal and vertical components. However, for most antennas, these offsets did not exceed 2-mm horizontal and 4-mm vertical components, respectively.…”