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public:vlbi_fundamantals:theoretical_delays [2014/07/22 11:52]
admin [Source structure]
public:vlbi_fundamantals:theoretical_delays [2014/07/22 12:02] (current)
admin [A few examples of constituents to the delay]
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 ===== A few examples of constituents to the delay ===== ===== A few examples of constituents to the delay =====
  
 +The various effects that have been described in the previous sections on the calculated time delay $\tau$ for simulated observations with stations Westford (U.S.A) and Wettzell (Germany) to source 0642+449 are evident in the Fig. below. These effects are ordered by magnitude from top to bottom. The upper plot displays the total delay which is mainly caused by the [[public:​vlbi_fundamantals:​theoretical_delays#​Earth orientation|Earth rotation]] and can be as large as one Earth radius. The next plot depicts the contribution of the hydrostatic delays at both sites to the total delay, i.e., the delay at Wettzell minus the delay at Westford. At each site, the hydrostatic delay at low elevation angles can be larger than 20 m, and it increases rapidly as the elevation angle decreases (Section [[public:​vlbi_fundamantals:​theoretical_delays#​Troposphere delay modeling|Troposphere delay modeling]]). The third sub-plot illustrates the influence of the axis offsets at Wettzell and Westford (Section [[public:​vlbi_fundamantals:​theoretical_delays#​Axis offsets|Axis offsets]]), of the gravitational effect of the Sun (Section [[public:​vlbi_fundamantals:​theoretical_delays#​General relativistic model for the VLBI time delay|General relativistic model for the VLBI time delay]]), and of the solid Earth tides (Section [[public:​vlbi_fundamantals:​theoretical_delays#​Station Coordinates at the Time of Observation|Station coordinates]])). The bottom plot contains the influence of the high-frequency Earth rotation model accounting for the ocean tides (Section [[public:​vlbi_fundamantals:​theoretical_delays#​Earth orientation|Earth orientation]]),​ as well as the effect of ocean loading (Section [[public:​vlbi_fundamantals:​theoretical_delays#​Station Coordinates at the Time of Observation|Station coordinates]]) at the sites on the calculated delay $\tau$. ​
  
 +{{ :​public:​vlbi_fundamantals:​figure_7_infl.png?​500 |Influence on the calculated time delay $\tau$ for simulated observations with stations Westford (U.S.A) and Wettzell (Germany) to radio source 0642+449. From top to bottom: Total delay (mainly caused by Earth rotation), troposphere,​ axis offsets, gravitational effect of the Sun, solid Earth tides, high-frequency model for the Earth rotation caused by ocean tides, and ocean loading (by courtesy of Lucia Plank)}}
  
  
public/vlbi_fundamantals/theoretical_delays.txt ยท Last modified: 2014/07/22 12:02 by admin