United Vision Solutions Eagle Vision EV3000-D User Manual page 50

EV3000-D manual
1.5.1 Internal vs External NUC
1.5.1.1 Internal NUC
The EV3000-D thermal camera offers the capability to perform the NUC (Non Uniformity
Calibration) function both with and without the use of the internal shutter. When the system
NUC is performed with the internal shutter the FPA (Focal Plane Array) uses the internal
shutter as a flat (constant temperature) surface and performs the calibration to make all the
pixels uniform with respect to the shutter. This calibration is sufficient in most cases to
produce a high resolution image.
1.5.1.2 External NUC
The EV3000-D thermal camera can also perform a NUC without using the internal shutter by
looking at an external scene that is at uniform temperature, or, cover the front lens with the
tethered foam plug. This is usually accomplished by looking at a distant scene in narrow field of
view and defocusing the camera to produce a uniform blur in the image. External NUC can
also be accomplished by pointing the camera at the sky. The NUC function will then calibrate
the FPA to this uniform surface. It is important that the image look flat when the function is
performed.
The external NUC has the advantage that it will calibrate out differences in the optics as well as
the FPA. It also calibrates the camera to the actual scene temperature. Both of these functions
contribute to an image that is a little bit better than the internal NUC. External NUC should be
used when the users requires maximum performance from the Ranger III.
NOTE: External NUC can only be invoked via Menu commands.
Equipment described herein may require US Government authorization for export purposes. Diversion contrary to US law
is prohibited. ©2008 United Vision solutions, Co., Specifications are subject to change. Check website:
www.unitedvisionsolutions.com