:PROCEDURE: iug_plot2d_irio, vn, col, row, start_time=start_time, $ step=step, valrng=valrng, flipns=flipns, flipew=flipew, $ oblique_cor=oblique_cor :PURPOSE: Plot 2D image of the imaging riometer data obtained by NIPR. The data are mapped to 90km altitude in the magnetic coordinate. :KEYWOARDS: vn : tplot variables for image data col : number of column row : number of row start_time : start time of the images step: time step valrng: minimal and maximal values for display (default: [0, 4]) flipns: set to flip in the North-South direction (default: top is north) flipew: set to flip in the East-West direction (default: right is east) oblique_cor: if set, CNA for the oblique beams is corrected by CNA*cos(ze). :EXAMPLES: iug_plot2d_irio, 'nipr_irio_syo_cna', 3, 3, $ start_time='2003-02-09/01:30', step=60 :Author: Y.-M. Tanaka (ytanaka at nipr.ac.jp)