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Дата индексирования: Mon Oct 1 23:33:08 2012
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Поисковые слова: reflection nebula
World Coordinate System Display

World Coordinate System Display

If the image header contains World Coordinate System information, SAOtng will display WCS positions as the mouse is moved across the image. The format for the display is controlled by the Coords Menu (or using the right mouse button on the screen WCS display). The display defaults to zoom1 pixels if the header does not contain enough information.

WCS information is displayed on the lower part of the image. It also is displayed in the Control Panel; the user can turn on and off either of these displays. Turning off the image-based display and leaving on the panel-based display is sometimes useful on crowded images (or at least was requested by someone once!)

Retrieving RA/Dec positions from SAOtng

The coords public access point allows you to position the mouse and then retrieve the coordinates and value for that position. Unlike most public access points, coords does not execute immediately. Rather, it changes the SAOtng cursor to a blinking circle and waits. You can move the mouse to a location on the image or perform any other SAOtng function: change colormaps, re-scale, etc. When you have positioned the mouse correctly, press the Return key and the coordinates and raw data value will be returned for the specified position. The coordinates are returned in the current format, (e.g. if your image supports WCS information, you can get RA/Dec output). The syntax of coords is:

	xpaget SAOtng coords [hms|degrees|pixels]
Note that you can add an argument to specify a return format other than the current format (subject to availability of WCS info for that image).
Last Updated June 14, 1997