en:documentation:mosaic_tool

# Mosaic

This tool let you prepare a mosaic for your camera.
There is two way to open this tool:

- From the menu View, in this case the mosaic is centered on the screen center, corresponding with the last object search.
- From the right click popup menu, in this case the mosaic is centered on the mouse cursor position.

- You can adjust the coordinates of the mosaic center, or use the arrow button to move the mosaic. Press the Ctrl key for larger move or the Shift key for smaller.
- The camera rotation can be adjusted to change the global mosaic orientation.
- Give a name to the mosaic, this is use as the default file name and prefix every row in the file.
- Select the Finder rectangle that correspond to your camera. It is better if your imaging software can plate-solve and send the frame to Skychart. This way you get the exact size and orientation automatically.
- Change the size of the mosaic as you want.
- Set the vertical and horizontal overlap in percent.

When ready click the Save button to record the mosaic definition to a file you can later load in your imaging software.

You can also send the mosaic via the server connection.

Below is a description of the format if you want to write your own software to process this mosaic.

## Server message format

The server message use the same format as the information about a selected object. All fields separated by the <tab> character.

    > Chart_1 : 05h47m49s -02d42m13s Frm Orion_01 Dim: 114.76 x 86.76 ' pa: 30.00

- > indicate the start of the message.
- Chart_1 : the name of the chart containing the mosaic.
- 05h47m49s RA of the frame center using current chart equinox. The command GETCHARTEQSYS return the equinox.
- -02d42m13s Dec of the frame center.
- Frm indicate the object is a frame.
- Orion_01 the name of the frame that can be use for image filename.
- Dim: 114.76 x 86.76 ' the size of the frame in minute of arc.
- pa: 30.00 the frame orientation, 0-360 CCW. 0 is horizontal frame with north up.

## File format

The content of the file is the following:

    EQUINOX=2458714.1
    Orion_01 05h47m49s -02d42m13s 30.00 114.76 86.76
    Orion_02 05h45m13s -03d49m51s 30.00 114.76 86.76
    Orion_03 05h42m36s -04d57m28s 30.00 114.76 86.76

The first row contain the Julian day for the epoch of the coordinates. This can be the current date or J2000 depending on your coordinate setting.

Each following rows contain the following information separated by a single space:

- the mosaic name and a sequence number.
- the frame center right ascension.
- the frame center declination.
- the rotator position.
- the frame width in minute of arc
- the frame height in minute of arc