Mitigation of the errors introduced by incorrectly determined centers through increasing angular segmentation of the star target is discussed, and it is shown that imagers with a better resolution performance (i.e., higher SFR) suffer more from incorrectly determined centers than an equivalent system with a worse performance.

Small pixel shifts in the center location are shown to induce significant degradation in the measured SFR compared to the nominal, correctly centered measurements. The mathematical function for the measured intensity of a sinusoidal Siemens star target with an incorrectly determined center location is derived and shown to cause effective changes to the sampled spatial frequency of the sinusoidal Siemens star target. 4 – 11 However, to the authors’ knowledge, no error analysis of the SFR processing methods for imagery of a sinusoidal Siemens star has been conducted.Ī piece of the total error analysis for this process has been conducted by investigating the errors due to inaccurate center identification, and several findings are presented. Work has been conducted to compare the results of the sinusoidal Siemens star measurement to other techniques, such as edge-spread function measurements, 2, 3 and the Siemens star target has been implemented as a useful test methodology in numerous applications for SFR measurements. Modifications to the ISO 12233 photography resolution standard 1 in February, 2014, now include a sinusoidal Siemens star as an approved test target. Measuring the spatial frequency response (SFR) of an optical system remains an intricate task, with several test methodologies available to the optical scientist and engineer, including slanted edge tests and measurements from known noise targets.