| 569 |
|
|
| 570 |
<chapter><title>Projection Management</title> |
<chapter><title>Projection Management</title> |
| 571 |
<para> |
<para> |
| 572 |
|
Projections control how the geographic data is displayed on the screen. |
| 573 |
|
If multiple layers are loaded into Thuban where the geographic data |
| 574 |
|
is in a different projection system, then the user must tell Thuban |
| 575 |
|
which projection each layer has. The user must also tell Thuban which |
| 576 |
|
projection the map is in. This can be the same as the layers or a different |
| 577 |
|
projection in which case the layers are reprojected into that space. |
| 578 |
|
The map projection can be set using |
| 579 |
|
<menuchoice> |
| 580 |
|
<guimenu>Map</guimenu> |
| 581 |
|
<guimenuitem>Projection</guimenuitem> |
| 582 |
|
</menuchoice> and the layer projection can be set using |
| 583 |
|
<menuchoice> |
| 584 |
|
<guimenu>Layer</guimenu> |
| 585 |
|
<guimenuitem>Projection</guimenuitem> |
| 586 |
|
</menuchoice>. |
| 587 |
</para> |
</para> |
| 588 |
<section><title>Selecting a Projection</title><para/></section> |
<para> |
| 589 |
<section><title>Creating a Projection</title><para/></section> |
Thuban is distributed with a sample collection of projections. The |
| 590 |
<section><title>Editing a Projection</title><para/></section> |
user can create new projections and make them available to all |
| 591 |
<section><title>Importing/Exporting Projections</title><para/></section> |
future Thuban sessions. They may also be exported and imported so |
| 592 |
|
that custom projections can be distributed to others. |
| 593 |
|
</para> |
| 594 |
|
<section><title>Selecting a Projection</title> |
| 595 |
|
<para> |
| 596 |
|
The available projections are listed on the left. If the layer |
| 597 |
|
or map already has a projection it will be initially highlighted |
| 598 |
|
and will end with <varname>(current)</varname>. Selecting |
| 599 |
|
<varname>None</varname>will cause Thuban to use the data as |
| 600 |
|
it appears in the source file and will not use a projection. |
| 601 |
|
</para> |
| 602 |
|
</section> |
| 603 |
|
<section><title>Editing a Projection</title> |
| 604 |
|
<para> |
| 605 |
|
Whenever a projection is selected from the list its properties |
| 606 |
|
are displayed on the right. These properties can be changed |
| 607 |
|
and the changes saved to the selected projection using |
| 608 |
|
the <guibutton>Update</guibutton>. Only a projection that comes |
| 609 |
|
from a file can be updated, so if the current layer's projection |
| 610 |
|
is selectd, <guibutton>Update</guibutton> will be disabled. |
| 611 |
|
The <guibutton>Add to List</guibutton> adds the projection to the |
| 612 |
|
list of available projections as a new entry, and thus make it |
| 613 |
|
available to future Thuban sessions. Clicking <guibutton>New</guibutton> |
| 614 |
|
will create an entirely new, empty projection. The |
| 615 |
|
<guibutton>Remove</guibutton> button will permanantly remove a |
| 616 |
|
projection from the list of available projections. |
| 617 |
|
</para> |
| 618 |
|
</section> |
| 619 |
|
<section><title>Importing/Exporting Projections</title> |
| 620 |
|
<para> |
| 621 |
|
The projections that appear in the list of available projections |
| 622 |
|
can be exported to another file that the user chooses. By selecting |
| 623 |
|
one or more projections and clicking <guibutton>Export</guibutton> |
| 624 |
|
the user will be able to select a file to store those projections. |
| 625 |
|
The file can then be distributed to other Thuban users. To import |
| 626 |
|
a projection file the user can click <guibutton>Import</guibutton>. |
| 627 |
|
The imported projections are added to the list and are then available |
| 628 |
|
to the current session and any future Thuban session. |
| 629 |
|
</para> |
| 630 |
|
</section> |
| 631 |
</chapter> |
</chapter> |
| 632 |
|
|
| 633 |
<chapter><title>Table Management</title> |
<chapter><title>Table Management</title> |
| 643 |
<appendix><title>Supported Data Sources</title> |
<appendix><title>Supported Data Sources</title> |
| 644 |
<para> |
<para> |
| 645 |
</para> |
</para> |
| 646 |
|
<variablelist> |
| 647 |
|
<varlistentry> |
| 648 |
|
<term>Shapefile</term> |
| 649 |
|
<listitem><para></para></listitem> |
| 650 |
|
</varlistentry> |
| 651 |
|
|
| 652 |
|
<varlistentry> |
| 653 |
|
<term>DB2 file</term> |
| 654 |
|
<listitem><para></para></listitem> |
| 655 |
|
</varlistentry> |
| 656 |
|
|
| 657 |
|
</variablelist> |
| 658 |
</appendix> |
</appendix> |
| 659 |
|
|
| 660 |
<appendix><title>Supported Projections</title> |
<appendix><title>Supported Projections</title> |
| 661 |
<para> |
<para> |
| 662 |
</para> |
</para> |
| 663 |
|
<variablelist> |
| 664 |
|
<varlistentry> |
| 665 |
|
<term>Geographic</term> |
| 666 |
|
<listitem><para>Geographic</para></listitem> |
| 667 |
|
</varlistentry> |
| 668 |
|
<varlistentry> |
| 669 |
|
<term>Lambert Conic Conformal</term> |
| 670 |
|
<listitem><para>Lambert Conic Conformal</para></listitem> |
| 671 |
|
</varlistentry> |
| 672 |
|
<varlistentry> |
| 673 |
|
<term>Transverse Mercator</term> |
| 674 |
|
<listitem><para>Transverse Mercator</para></listitem> |
| 675 |
|
</varlistentry> |
| 676 |
|
<varlistentry> |
| 677 |
|
<term>Universal Transverse Mercator</term> |
| 678 |
|
<listitem><para>Universal Transverse Mercator</para></listitem> |
| 679 |
|
</varlistentry> |
| 680 |
|
</variablelist> |
| 681 |
</appendix> |
</appendix> |
| 682 |
|
|
| 683 |
</book> |
</book> |
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