Coordinate Systems

The topics below discuss how Mira works with the coordinate systems of images and plots.

World Coordinate System	Describes the FITS World Coordinate System.
Image Coordinate System	Describes how coordinate systems are used for measuring distances, angles, centroid positions, and other quantities in images.
Pixel Coordinate Definition	Describes how pixels are referenced and counted in image coordinates.
Subpixel Coordinate Definition	Describes how fractional pixels are counted in image coordinates.
Angle Measurement Definition	Describes how angles are measured for different coordinate systems.
Plot Coordinate Systems	Describes how coordinate systems are used in displaying 1-D data.
Plotting in World Coordinates	Describes how 1-D plots implement the image coordinate system.
Image Display Orientation	Describes how rows are counted in different image formats.
FITS Image Orientation	Describes how FITS format images are oriented for display.
Image Coordinate Display	Describes real-time readout of the image pointer (crosshair).
Adjusting the Image Cursor	Describes how to adjust and position the image cursor.
World Coordinate System Keywords	Describes header keywords used to describe world coordinate systems.
Set X-Axis Linear Format	Configures the X world coordinate display when the X coordinate is calibrated in linear units.
Set Y-Axis Linear Format	Configures the Y world coordinate display when the Y coordinate is calibrated in linear units.
Set Pixel Value Format	Configures the display of pixel (Z) values.

The topics below discuss tools used for calibrating and working with world coordinate systems

Astrometric Calibration	Creates a "plate solution" for an image using the coordinates of at least 3 marked stars.
Set Arcsecond Scale	Assigns an arcsecond scale to an image.
Set Equatorial Scale	Assigns a simple equatorial coordinate system of (right ascension, declination) to an image.
Set Independent Linear Scales	Sets linear coordinate scales that differ in each axis.
Set Linear Coordinate Units	Sets the name for linear coordinate units in each axis.
Calibrate Linear Scale	Uses a mouse-drawn line to create a linear calibration in both axes based on a user-defined distance and coordinate units.
Delete WCS	Deletes any type of World Coordinate System scale from the image, reverting it to the (column,row) system.
List WCS Keywords	Lists the values of world coordinate system keywords in the image header.
Go To Coordinates	Moves the image cursor to a target position, or loads the current position in either pixel or world coordinates.
Go To Object	Moves the image cursor to the work coordinates stored in the OBJECTRA and OBJCTDEC keywords.