Centroid Measurements

The Centroid Measurement computes a high precision estimate of the position of a small object such as a point source.

To make a centroid measurement, position the Image Cursor near the target object, then click on the toolbar or click Centroid in the Measure pull-down menu.

If an image set is open in the source Image Window, you can choose whether to measure only the active image or to measure the entire image set. If measuring the entire set, Mira finds each successive centroid by searching the next image within some radius of the current position.

Measurement Results

Measurements are tabulated in the Centroid Measurements window as shown below. This is a Report Window with built-in functionality for sorting, rearranging, copying, and saving to a file..

Measurements for all objects in all images and all Image Windows go into a single Report window. If you want to clear the Report window of prior measurements, make sure the window has focus, then click [Clear] in the View menu.

The items in the Report window are described in the table below.

Centroid Quantities

#	The sequence number of the measurement.
Image	The name of the image that was measured
X	The X coordinate of the centroid position. If the image has a WCS calibration, this is right ascension, otherwise this is the column coordinate.
Y	The Y coordinate of the centroid position. If the image has a WCS calibration, this is declination, otherwise this is the row coordinate.
Value	The peak luminance of the object.
Col	The column coordinate of the centroid position
Row	The row coordinate of the centroid position.

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