ALMA Memo 461 The Calibration System revisited
نویسنده
چکیده
Different strategies of use of the polarization grids combined with two temperature loads for calibration are explored. It is shown that a system with an ambient load, a hot (100 • C or so) load, and a semi-transparent grid with 50 % transmission allows to reach a 1 % accuracy on the receiver gain even in presence of saturation. The best precision requires a device which offers the 5 major combinations: Sky, Sky+Ambient, Sky+Hot, Ambient, Hot. If saturation is negligible, the system can be used as a standard dual load calibration device, with better accuracy.
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تاریخ انتشار 2003