1 UV_STAT UV_STAT : Analyse a UV table for weighting parameters and map cell size. UV_STAT analyses a UV table from the weighting point of view to evaluate the beam size and the expected rms noise as function of Weighting parameters (UV_CELL, mode WEIGHT) or Taper (UV_TAPER, mode TAPER). UV_STAT computes dirty beams for various tapers or "Robust weighting" parameters, and evaluate the expected rms noise for each of them. 2 UV_TABLE$ TASK\FILE "UV table" UV_TABLE$ The UV table name. Default extension is .UVT. This UV table will be sorted if necessary. 2 UV_MODE$ TASK\CHARACTER "Checking mode" UV_MODE$ The checking mode can be TAPER or WEIGHT. If TAPER is selected, UV tapers ranging from 50 to 800 m (in powers of sqrt(2)) will be used to produce 10 different beams. The weighting mode is then defined from parameter UV_CELL. If UVCELL[2] is 0, natural weighting is used. If not, robust weighting over cell sizes UV_CELL[1] (default 7.5 m) with "Robust" parameter UV_CELL[2] will be used. If WEIGHT is selected, "Robust" weighting parameters ranging from 0.03 to 300 by factors sqrt(10) will be used to produce 10 different beams. The taper defined by UV_TAPER will be used. UV_CELL[1] specifies the cell size to define the robust weighting. 2 UV_TAPER$ TASK\REAL "UV taper (maj, min, angle) " UV_TAPER$[3] The 2-dimensional UV taper: 1/e level along the major axis, 1/e level along the minor axis, position angle in degrees. 2 UV_CELL$ TASK\REAL "UV cell(m), for unif. weighting" UV_CELL$[2] UV_CELL[1] is the UV cell size for uniform/robust weighting. Should be of the order of half the dish diameter, or smaller. UV_CELL[2] is the "Robust" weighting parameter. 0 means natural weighting. When non-zero, the "Robust" parameter refers to the threshold selected for uniform weighting. 1 gives usually reasonable results. Smaller parameters produce more uniform weighting, but higher noise. Larger parameters produce larger beams,, but smaller noise. 2 DO_BEAMS$ TASK\LOGICAL "Save beams on disk ?" DO_BEAMS$ Logical flag to indicate whether the 10 computed beams should be saved or not. If YES, beams will be saved in a file with same name as the UV table and extension ".beams" 2 WCOL$ TASK\INTEGER "Weight channel" WCOL$ The channel from which the weight should be taken. WCOL$ set to 0 means the central channel. 1 END