AIPS HELP file for TRC in 31DEC13
As of Thu May 23 6:08:58 2013
Type: Adverb (Real array, 7 elements)
Use: The array subscripts of the pixel at the Top Right
Corner of the desired subarray of the image. The first
value in TRC gives the column number of the pixel; the
second value in TRC gives the row number of the pixel.
The array contains 7 dimensions.
Null value: 7*0
Null value assignment is generally (N,M,x,...), where
N and M are the dimensions of each plane of the image
and where x,... is the 3rd,... axis dimensions for
operations on full images or BLC(3),... for operations
on single planes.