Distance and Angle


The Distance & Angle measurement tool is used to measure the distance between two points and the angle of the line connecting them. The results are reported in the Distance Measurement Pane . This command opens and closes using the toolbar button. The command opens with Marking Mode (top button) active. Marker properties are set in the Marker Properties dialog opened from the button on the Distance & Angle toolbar.

Procedure

First, activate the Distance & Angle command. [more] Then:

  1. Be sure the drawing and centroiding Properties are set as desired. [more]

  2. Move the mouse pointer to the starting position. Press the left mouse button and hold it down.

  3. Drag the mouse pointer to the ending position and release the mouse button. The result is listed in the Distance Measurements Report window.

Coordinate Systems

Measurement Results

Measurements are tabulated in a Report Window designed specifically for this command. Using this window, the measurements may be sorted, rearranged, saved to the clipboard or a file, etc.

If the image has a World Coordinate System ("WCS") calibration, then X1, X2, Y1, and Y2 give the WCS values corresponding to listed column,row coordinates.

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

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

Distance & Angle Measurements

#

The sequence number of the measurement.

Image

The name of the image that was measured

Distance

The distance in pixel units, or arcseconds if the image has a WCS calibration.

Angle

The angle in degrees, or a Position Angle if the image has a WCS calibration.

X1

The X coordinate of the starting point.

Y1

The Y coordinate of the starting point.

X2

The X coordinate of the ending point.

Y2

The Y coordinate of the ending point.

Col 1

The column coordinate of the starting point.

Row 1

The row coordinate of the starting point.

Col 2

The column coordinate of the ending point.

Row 2

The row coordinate of the ending point.

Marking Endpoints

As with other interactive marking commands, the Distance & Angle command can use the exact marked endpoints or it can compute either or both of the endpoints as a precise centroid position. All 4 combinations of centroid or no centroid and starting point or ending point are possible. To set this option, click on the toolbar to open the Marker Properties dialog for this command, then select the Centroid page.

Examples of Distance & Angle Measurement clarifies the effect of centroiding the starting and ending points of the measurement. In the examples, the same starting and ending points were located with the mouse but some of them were automatically centroided by Mira.

Related Topics

Measuring Images, Report Windows, Image Windows, Image Display Orientation, Pixel Coordinate Definition, Sub Pixel Coordinate Definition, World Coordinate System