→How it works
== '''How it works''' ==
Use imageJ’s circle tool (shift + oval tool) to measure the spot/ring patterns concentric to the (000) direct beam. From the area measurement, the radius (G) is found. From G = 1/d in reciprocal space, the d-spacing is calculated for each measurement made.
'''Overlay''' is the second mode, which draws the positions of the measurements made back onto the diffraction pattern image, and displays an inset with the calculated d-spacing values for each ring. It also labels the rings and d-spacing measurements in the inset so that there is traceability between the calculated values and the measurements made using the circle tool. This visual correlation between d spacing and measured rings is useful for indexing diffraction patterns, because the TEM operator can subjectively take ring intensity into account. For example, you may be deciding between two phases that have similar d-spacing lists, but different ring intensities. This helps determine which rings are the most intense in the patterns adding a data component that is sometimes lost in SAD analysis.