GETNSCMTF

Calculate the X and Y direction geometric MTF in the non-sequential mode based on the spot diagram on Detector Rectangular.

Syntax:

GETNSCMTF freq, surface, object

Discussion:

The freq argument is designed for spatial frequency in MTF Units (see "MTF Units"). If the frequency is less than zero, GETNSCMTF uses its absolute value. The Surface argument allows the feature to be used in a sequential and non-sequential mixed mode. For a pure non-sequential mode system, the Surface number should be always set to 1. The Object argument points to the detector on which the MTF is calculated. It should be set to a Detector Rectangle only. This calculation uses the Geometric MTF method, which does a Fourier transform of the Spot Diagram on the Detector Rectangle.

The data is returned in first vector arrays, vec1(), with the following format: Vector position 0: X direction; Vector position 1: Y direction. See VEC1, VEC2, VEC3, VEC4 for more information on how to use vector arrays.

Example:

! This macro computes the X & Y direction NSC MTF at 50 lp/mm
! at object 10 – Detector Rectangular
 
PRINT "Resetting detectors..."
y = NSDD(0, 0, 0, 0)
PRINT "Tracing rays..."
NSTR 1, 0, 0, 0, 0, 1, 0
 
PRINT "Calculating MTF X and Y..."
GETNSCMTF 50.0, 1, 10
PRINT "mtf X = " +  $STR(vec1(0))
PRINT "mtf Y = " +  $STR(vec1(1))

Next:

• GETPSF