Status of EVN Amplitude Calibration --------------------------------------------- Session 1/2011 --------------- The following table shows the median absolute amplitude error for EVN stations in the first session of 2011 (Feb/Mar). These results were derived from the pipeline amplitude self-calibration results of all EVN experiments. The number in brackets after each entry is the number of experiments that were used to determine the median error for that entry. ============================================== Station 18 cm 5 cm 6 cm ---------------------------------------------- Jb 0.08(2) 0.12{3}* 0.10(4) Ef 0.08(2) 0.02(3) 0.05(4) Mc 0.12(2)* 0.10(3) 0.05(4) On 0.08(2) 0.14(3)* 0.09(4) Tr 0.07(2) 0.05(2) 0.03(4) Wb 0.03(2) 0.06(3) 0.03(4) Ys 0.02(3) 0.04(4) Hh 0.04(1) 0.04(1) 0.05(3) Ur 0.12(2)* 0.04(3) Sh 0.13(2) 0.05(1) 0.07(3) Bd 0.09(2) 0.04(3) Sv 0.08(2) 0.07(3) Zc 0.14(2)* 0.22(3)* ============================================== The blank entries indicates insufficient data. The numbers above are the median absolute error in the antenna gain amplitude (as calculated from pipeline amplitude self calibration). A value above 0.1 indicates a significant error which should be investigated. In addition to the absolute errors summarized here, the EVN pipeline provides details on every experiment processed at JIVE including the sign and time variability of the errors. In each experiment, the self-calibration results of a bright and compact source were used to get the reliable results. *Ur: The measured Tsys was slightly higher than it should be (~23 K), most likely caused by bad Tcal measurments.This problem was noticed in N11L3 again and has been corrected in making Session 2/2011 antab files. *Mc: The number may not mean bad amplitude calibration station. In N11L3, the pipeline reported a median error of 0.07 when the rest stations had good amplitude calibration. The subbands outside of its receiver bandwidth have low correlation amplitude and were usually not flagged out in 18cm 1Gbps experiments. *Jb: Jb2 C-band receiver was back to work at 5cm in Session 1/2011. As its system and performance is not stable, it is hard to track the problem. Now, Jb1 have a sensitivity: 65 Jy at 18cm and 130 Jy at 6cm, much lower than that (44 Jy at 18cm and 35 Jy at 6cm) in the EVN status table. *Zc: No Tsys available. Jun YANG for the Science Operation and Support Group (JIVE)