REWEIGHT Type: Adverb (Real(2)) Use: All uv data have associated weights which express the relative value of the data. Internally, these weights are treated as statistical weights (i.e. 1 / variance (amplitude)). These weights are used in making images but are modified by uniform weighting and tapering. In practice, the weights coming into AIPS from non-AIPS calibration systems are in arbitrary units so a renormalization of the weights may be necessary when data sets are combined. The adverb REWEIGHT can be used to modify the relative weights of the two input data sets. The simplest way to determine the appropriate relative weighting is to image each set of data independently in the same fashion as the desired final image (i.e. using the same IMSIZE, CELLSIZE, UVWTFN, UVBOX, and UVTAPER but not necessarily doing a deconvolution). All AIPS imaging tasks report the "sum of the gridding weights" in the message file. This is the sum of the weights after all corrections are applied (this value has been written into the history file since 15JUL89). REWEIGHT is a pair of values to be multiplied by the input weights for the first (1) and second (2) input uv data file. These values should be set such that the two data sets will have the desired relative sum of weights. For example, if the two data sets before DBCON give a sum of gridding weights of 1.0E5 and 2.0E2 when imaged by IMAGR AND you wish to make them contribute equally to the final image then use: REWEIGHT = 1.0,1.0e5/2.0e2 (or 1, 500). REWEIGHT is also used by a variety of tasks for various re-weighting purposes. Null value: 0 will be interpreted as 1.0 Tasks: BSGEO...Beam-switched Az-El image to RA-Dec image translation REWEIGHT(2) minimum convolved weight. BSGRD...Task to image beam-switched single-dish data REWEIGHT type output, min convolved weight DBCON Used to concatenate 2 uv data sets. REWEIGHT described above in detail. DSKEW...Geometric interpolation correction for skew REWEIGHT interpolation halfwidth, min fraction good pixels FLATN...Re-grid multiple fields into one image incl sensitivity REWEIGHT interpolation halfwidth, min fraction good pixels OGEOM...Simple image rotation, scaling, and translation REWEIGHT interpolation halfwidth, min fraction good pixels OHGEO...Geometric interpolation with correction for 3-D effects REWEIGHT interpolation halfwidth, min fraction good pixels SDGRD...Task to select and image random-position single-dish data REWEIGHT type output, min convolved weight SDIMG...Task to select and image random-position single-dish data REWEIGHT type output, min convolved weight SYSOL...Undoes and re-does nominal sensitivity application for Solar data REWEIGHT does additional scaling of visibilities, weights. TVIEW...Display image cube in all 3 transpositions with rotation & reference. REWEIGHT interpolation halfwidth, min fraction good pixels TYAPL...Undoes and re-does nominal sensitivity application REWEIGHT does additional scaling of visibilities, weights.