An antenna can be specified by the index of the antenna or a regular expression. A full antenna name consists of three hyphen ('-') separated fields. The first field is the antenna name, the second is the side band name and the third is the polarization name. Each of the three fields can be a regular expression. All missing fields after the last specified field are replaced by "wild card" regular expressions.
E.g., a fully qualified name for C11, upper side band, 175-MHz polarization channel (nominally the LL polarization) can be expressed as:
All central square antennas, with upper side band and 130-MHz (nominally the RR polarization) polarization channel can be expressed as:
(Here '.' matches one instance of any character and the '+' operator operates on '.' zero-or-more number of times. Hence ".+" is equivalent to the '*' wild card character. This is the POSIX regular expression syntax).
All central square antennas with upper sideband and either polarization channel can be expressed as:
Finally, all central square antennas without any selection on the side band and polarization channel can be expressed as:
All above examples, but with only arm antennas can be expressed by replacing ``C.+'' in the above examples by ``[EWS].+".
Baselines can be specified by the index of the baseline or a regular expression describing a baseline name.
A full baseline name is composed of two antenna names separated by a colon (':'). A fully qualified baseline name between the upper-side band, 175-MHz polarization signals from antennas C11 and C12 would be
Any of these fields can be regular expressions. Hence to choose all baselines with antenna C11 upper side-band signals from either of the polarization, one would use the baseline name as:
If only the first field of antenna name is given, the others are taken to be the wild card characters.
If second fully qualified antenna names is missing from the baseline name, it is also replaced by wild card.
These selections will exclude all self correlations. Also, if a baseline has already got selected in a previous selection, it will be excluded from all later selections.
To select the self correlations, one must add 'A' to be beginning of the antenna names. In such a case, the name of the second antenna is redundant and therefore not required.