Improved Accuracy of Shift Calculations through Appropriate Filtering of High Resolution Navigators
Nishimura D, Schaffer R
Navigators are used to detect translation and phase-correct corresponding data frames using cross-correlation. The quality of the corrected image is a function of how accurately the shifts can be calculated. When high precision is attempted (as in high-resolution imaging), the SNR can be quite low. While filtering to maximize the SNR at the peak of the cross-correlation may improve shift calculations, we show that a filter that results in more curvature at the cross-correlation peak is superior. Through appropriate filtering, the accuracy of the measured shift and, thus, the quality of the corrected image can be improved.