Task: xyphase Purpose: Determine XY phase corrections from on-line measurements. Categories: uv analysis XYPHASE is a MIRIAD task, which determines XY phase corrections from the on-line XY phase measurements. This can calculate an antenna gain and/or a bandpass function. This cannot cope with multi-IF data-sets. Bad solutions will result if you attempt to use it for this data. The input data should contain either the "xyphase" uv variable (the on-line XY phase measurement), and/or autocorrelation data. The autocorrelation data is required if the bandpass is being solved for. Note that the "xyphase" variable is lost if the data enters Miriad via FITS (unless ATMERGE is used). The autocorrelation data is currently not written when using the standard correlator configurations. Key: vis The input visibility data-set. No default. This should contain raw ATCA polarisation data (i.e. XX,YY,XY,YX correlations). Key: select Normal uv selection criteria. The default is to select all data. Polarisation selection should not be used. Key: refant The reference antenna. By default XYPHASE computes the gains and bandpasses for all antennae. By specifying a reference antenna, XYPHASE finds solutions for only the reference antenna, and sets the other phases to zero. This is as other programs (such as GPCAL and MFCAL) can determine all but the reference antennas XY phases. Key: interval This gives one or two numbers, both given in minutes, both being used to determine the interval over which the antenna XY phase is assumed to remain constant. The first number gives the maximum length of a solution interval. The second number gives the maximum gap size in a solution interval. A new solution is started when either the maximum time length is exceeded, or a gap larger than the max gap is encountered. The default is a maximum length of 5 minutes, and a gap size which is the same as the maximum length. Key: break The times, in the normal Miriad format, where to insert the break point. A ``break point'' gives a time where some form of instrumental glitch took place, and the xyphases jumped. By giving a break point, you prevent a solution interval from spanning this time, and you inhibit gain interpolation across the time. Key: options Extra processing options. Several options can be given, separated by commas. Minimum match is used. noxy Do not determine the antenna XY phases. By default XYPHASE will solve for this when the "xyphase" variable is present in the data. nopass Do not determine the XY bandpass function. By default XYPHASE will solve for this when autocorrelations are present in the data.

Generated by miriad@atnf.csiro.au on 21 Jun 2016