Construction of horizontals

The purpose of horizontals building is the receiving of information on a relief of district in a linear kind by a matrix of relief heights (DEM).

Building of horizontals is executed in borders of DEM, by parameters set by user.

If it is loaded some DEM, horizontals will be created by all DEM as by overlapped, and by not overlapped one. It is necessary to take into account that, horizontals will be built only in area of the map covered by MH. On sites poor by the matrix data the horizontals are not forming. In a case if matrixes of heights have no overlapping the horizontals can be generated with "holes" or breaks.

Building of horizontals is executed in some stages:

Processing of relief heights matrix

Processing of horizontals

Stages are independent and on a physical essence represent two independent processes. The purpose of processing a relief heights matrix is the smoothing the forms of a relief and specification of values of DEM nodes on local sites in region of location of heights marks and objects of hydrography. The purpose of forming horizontals is an automatic creating the metrics of relief isolines by its representation in the form of a regular grid of heights.

As a result of work of the program the user map is created onto which the generated horizontals are placed, the map has the same name as a matrix of heights, or a name specified by user. If the user map with the specified name onto the moment of formation is active the horizontals will be added into it after acknowledgement of the user onto corresponding query. But in this case it is possible the situation of double horizontals if those already were in the user map.

Horizontals can be generated within the limits of all region on available matrix data, but the user can change area of construction of horizontals. For a choice of area of construction the buttons are intended in Output map group: All area, Inside a framework, Inside a contour and Inside object. By default all region is established as the area of construction. At a choice of area of construction inside a framework it is necessary to specify rectangular area of construction. At a choice of area of construction inside a contour it is necessary to specify the any closed area, and at construction inside object - the area or closed linear object.

Before start of forming contours (Run button) it is necessary to execute some preliminary actions

1. To specify a name of an output file. By default it is formed on the basis of a name of the basic map, but at desire the name of a file and its location can be changed, using a window of input and the button near it.

2. To choose area of construction of contours. By default contours are formed onto all region. This area is used and for processing matrix data. If the region of works is sizeable on dimensions this possibility allows to reduce considerably time for formation of contours onto a local site.

3. To specify parameters of processing of matrix data and constructions of contours. Originally parameters of processing are established by default, but frequently there is a necessity to change them.