Tektronix SPG8000 Technical Reference page 126

SDI button menu (Option SDI only)
Zone plate pattern control
parameters
114
7. When you are done altering parameters, scroll to the Save As: menu item at
the bottom of the menu and use the left (◄) or right (►) arrow button to
select User Custom 1 or User Custom 2.
8. Press the ENTER button to save the modified signal.
NOTE.
Zone plate variations can be sinusoidal, square, or triangular. These
discussions of zone plated parameters will refer to sinusoidal variations for
convenience.
Zone plate patterns are made up of sinusoidal variations in luminance, with the
"peaks" of the sine waves resulting in white areas on the video screen and the
wave "troughs" shown as gray or black. The cycles can occur in all three of the
video dimensions: horizontally, or along each line of the picture; vertically, or
"down" the video frame; and temporally (with time). The three dimensions are
often referred to by the shorthand designations of X, Y, and T.
The luminance of any point in the picture, physically on the screen and in time, is
determined by the value of sine at that particular point; the value of sine follows
from the phase of the cycle at that point; and (by the definition of a zone plate)
the phase of any point is determined by the equation:
where x, y, and t are the coordinates of the point in question and k
k , k , k , k , k , and k
2 2
XT YT XY X Y
All instrument zone plate patterns are defined with coefficients of ten parameters
that correspond to the constants in the above equation. Note that while the
possibilities are virtually endless, most common zone plates are defined with
only one or two parameters, while the coefficients of the remaining parameters
are kept at zero.
The instrument generates six standard zone plate signals: circle frequency,
diagonal frequency, horizontal sine frequency, horizontal sweep frequency,
vertical sine frequency, and vertical sweep frequency. Each standard zone plate
signal has a pattern control parameter. (See Table 31.) This pattern control
parameter is unique to the zone plate signal it is associated with.
are constants.
2
T
SPG8000 Technical Reference
, k , k , k ,
Ф X Y T