We begin by reading a scan's worth of raw data from a HDS file.

get_data,'1998-02-14.022'

Warning(HDS_OPEN): not standard file name!
HDS-file opened; mode=READ.
% Compiled module: POLYFITW.
% Compiled module: STDEV.
GeoParms loaded.
GenConfig loaded.
Scantable created.
% Compiled module: UNIQ.
StarTable created; number of entries = 1.
Finished reading catalogs.
Finished reading catalogs.
Number of new diameters added: 1.
Number of new (R-I) values found: 0.
Finished reading catalogs.
Records loaded.
The fringe data are stored in bincounts. These are the 2 ms count rates for every spectrometer, bin, channel, and frame. At NPOI, there are 3 spectrometers, 8 phase bins across a single fringe, and 32 channels per spectrometer. In this example, there are 42300 frames (2 ms records of fringe data).

help,bincounts

BINCOUNTS (RAWDATA) BYTE = Array[3, 8, 32, 42300]
To display a frame, use displayframes. Always select a single spectrometer, and all bins. Select various ranges of channels and frames, and see what happens.

displayframes,bincounts(0,*,*,46)

?


displayframes,bincounts(0,*,0,0:100)
?


The fringemovie procedure lets you view a movie of the fringe motion!

fringemovie,bincounts(0,*,*,0:100)

?


Let's now introduce the name "channeled" fringe. This term refers to the fact that the fringe pattern is polychromatic. The following command produces an image showing colored fringes.

fringeimage,1