Determining 4-Bar Target Sizes

SBIR recommends at least four 4-bar targets be used to develop a MRTD curve. The following sheet formulates the spatial requencies. Each of the targets are based on particular camera parameters and collimator focal length.

The formulated target frequencies are related to the Nyquist frequency (symbol Fo) of the unit under test, SBIR typically suggests 0.2, 0.5, 0.8 and 0.95 of the Nyquist frequency (Fo)


Input

The first step is to Calculate the IFOV of your sensor and use that result in the section below::

  • Nyquist limit when a starring array has a 100% fill factor

Results



.200 bar width is or
.25f0 bar width is or
.35f0 bar width is or
.38f0 bar width is or
.40f0 bar width is or
.50f0 bar width is or
.60f0 bar width is or
.70f0 bar width is or
.75f0 bar width is or
.80f0 bar width is or
.95f0 bar width is or
1.0f0 bar width is or
1.2f0 bar width is or

Max bar width for 312 0.1616 Inches
Max bar width for 313, 316 & 317 0.2727 Inches
Max bar width for 314 0.1252 Inches
Max bar width for 315 0.485 Inches