28-29 October 2021
TU Wien Freihaus
Europe/Vienna timezone
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Contribution Talk

TU Wien Freihaus - DC 02 030 "Jupiter"

Cable delay calibration of EU-VGOS data in the geodetic analysis


  • Jakob GRUBER

Primary authors



The phase calibration reference signal of a VLBI station is carried by a cable from the maser in the control room to the phase calibration signal generator at the antenna room. Any changes in the length of the cable also introduce delays in the phase calibration signal. The phase calibration correction is applied at the fringe-fitting stage; therefore, the instrumental delays from the injection point to the sampler are corrected, and delays due to cable length changes of the uplink cable are introduced. The cable delay is measured at the station by the so-called Cable Delay Measurement System (CDMS), or a proxy is estimated from the phase calibration signal during fringe-fitting (Pcmt). Both delays are stored in the vgosDb file. In this talk, we present a new feature of the Vienna VLBI Software (VieVS), which can select either CDMS or Pcmt to correct the group delays by the cable delays at the geodetic analysis. Furthermore, we will show the impact of either using CDMS or Pcmt on the geodetic results of EU-VGOS data.