Comparison of subsampled and fully sampled system MTF curves inferred from the line-spread function using the DIPOL camera

The inferred line-spread function is an easy technique for measuring orthogonal components of the two-dimensional modulation transfer function (MTF), even from the air. However, it has been most commonly used for cameras for which the resolution is nowhere near the Nyquist frequency. The purpose of such limitation is so that the pixel sampling does not have a serious consequence on the measurement of the MTF. The binning capability of the purely digital DIPOL camera is used to demonstrate that using this method even in moderately oversampled systems does not impact results as long as certain averaging techniques are used. A brief tutorial of the normalization and pitfalls of the method will also be given so that this powerful and simple measurement will become more widely used. Example images will also be shown of mine simulators, together with polarization-product images.