Uniting region of works into one sheet

This task is intended for uniting adjacent sheets of a vector map into the output vector map of format SIT containing one sheet. The task can be used to obtain a single map of the subject of Federation or other region. In the process of combining the input sheets into one sheet there can be performed merge of polygonal and non-closed linear objects going onto frames of adjacent sheets.

The program of combining adjacent sheets should be carried out after processing of the input map by programs «Check of vector map quality» and «Coordination of adjacent sheets» in the edit mode (the menu Tools - Run Applications - topic the Check and correction of data).

The projection of a resulting map can be set by means of the dialog element the Projection in group the Output map.

The output data of the program of uniting adjacent sheets are:

- general map of region in format SIT;

- protocols of process of uniting adjacent sheets of digital topographic maps in text format (LOG-file) and in binary format (ERR-file) in the subdirectory \Log.

Viewing the text protocol (LOG) can be carried out in program WordPad or other browser of simple text documents. For viewing the binary protocol it is necessary:

- to open the output map in format SIT;

- to make active the mode of the Map Editor «View error».

Process of uniting adjacent sheets includes the following main steps:

- creating a sheet of output map;

- copying the objects of the source sheets onto the output map;

- merge of polygon and not closed linear objects going onto frameworks of adjacent sheets.

The program can work in modes of a merge or copying of objects of initial sheets depending on the option of dialog «Merge objects».

If the mode «Merge objects» is disabled, the uniting process is completed after the transfer of objects of initial sheets onto the output sheet.

If a mode «Merge objects» is enabled, after the transfer of objects onto the output sheet the automatic merge of objects of adjacent sheets going onto a frame is carried out.

At need of a merge of objects on border of adjacent sheets it is necessary to set the option Merge objects with specifying a threshold of a merge in map millimetres in the window the Threshold for uniting (mm). In the process of uniting (merging) the objects of adjacent sheets the non-closed lines and polygon objects participate. Automatically the objects are merged, the distance between the vertices of which does not exceed the threshold of a merge. For determining an exit of object onto a frame the distance equal to half of the preset threshold of a merge is used.

At a merge of objects the following actions are carried out:

- search of object of the current sheet that goes onto a frame;

- search of the reply object on the next sheet;

- check of matching the metrics of objects;

- check of  matching semantics of objects (values of semantic characteristics should coincide);

- creation of united object and deleting of two initial objects.

By means of Setup button in the group of Semantics and layers excluded from processing, it is possible to exclude from processing some semantics, layers and objects of a map, for example, objects of a mathematical basis (horizontal and vertical lines of a rectangular grid, outputs of lines of parallels and meridians, frameworks of initial sheets and others). For this purpose in dialog Select skipping semantics and layers it is necessary to set the required layers in the List of layers table and to append objects into the List of objects table.

When merging objects, the compliance of their semantic characteristics is checked. Checking a conformity of some semantics at a merge can be disabled, for example, semantics: vegetation type, a vegetation kind, width by a scale. For this, it is necessary to specify the semantics to be skipped in the List of semantics table.