منابع مشابه
ALMA M&C Frequently Asked Questions
The requirements for ALMA M&C, spelled out in [2], include certain levels of determinism that Ethernet cannot guarantee. The use of a master/slave protocol will guarantee a maximum latency for an M&C transaction when used with either CAN or Ethernet. Ethernet has been used with deterministic higher layer protocols such as token rings, but these are declining in use. CAN, however, is naturally m...
متن کاملALMA Chapter 3.1: Calibration issues for ALMA
The precision imaging to be attained by the ALMA will be achieved through accurate calibration. The types of calibration are summarized in Table 3.1. Table 3.1 ALMA Calibration Requirements. Pointing 0.6" absolute Primary Beam 2-3% Baseline Determination 0.1 mm Flux Calibration 1% absolute flux accuracy goal Phase Calibration 0.15 radian at 230 GHz Bandpass Calibration 10000:1 to 100000:1 Polar...
متن کاملThe weak Hawkins-Simon Condition
A real square matrix satisfies the weak Hawkins-Simon condition if its leading principal minors are positive (the condition was first studied by the French mathematician Maurice Potron). Three characterizations are given. Simple sufficient conditions ensure that the condition holds after a suitable reordering of columns. A full characterization of this set of matrices should take into account t...
متن کاملALMA Memo XXX Bandpass Calibration for ALMA
This memo contains a detailed evaluation of the expected performance of the bandpass calibration for ALMA. We evaluate the limitations on the bandpass accuracy due to the imperfect knowledge of the atmospheric transmission. We show that the best bandpass accuracy is obtained when the amplitude calibration is applied in a single-load scheme. The proposed scheme is a variant of the so-called band...
متن کاملALMA Memo 493 Finding Fast Switching Calibrators for ALMA
In order to perform fast switching phase calibration effectively, we need to have a database of bright point-like sources at millimeter wavelengths. Optimally, this would include flux measurements at 86 GHz and spectral information at higher frequencies. We present a sample of 31145 compact flat spectrum radio sources with −40 < δ < +60, presumed extragalactic, which will be likely candidates f...
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ژورنال
عنوان ژورنال: Dance Research Journal
سال: 1998
ISSN: 0149-7677,1940-509X
DOI: 10.1017/s0149767700004952