Building a grid of air defence (PVO)

Dialogue is intended for building a grid of air defence on topographic maps in accordance with the order of the Minister of Defence of the Russian Federation №188 dated May, 15th, 1997.

Air defence grid on topographic maps is intended for coding the coordinates at the alarming the troops, authorities and institutions about the air enemy, own aircrafts, and also at solution of other tasks connected with data exchange about coordinates of objects.

Air defence grid on topographic maps covers territory of Northern hemisphere of the globe. Grid basis are zones, sectors and squares. All covered territory is divided into 92 zones of four types (A, B, C and D) in the following order:

In hemispheres the numbering of zones is made by horizontal rows from West to East, starting from the zone adjoining the North Pole, and terminating on the extreme southeast zone.

zones of type A - onto 10 sectors in five horizontal rows in two sectors in each row;

zones of type B - onto 8 sectors in four horizontal rows on two sectors in each row;

zones of type C - onto 8 sectors in two horizontal rows on four sectors in each row;

zones of type D - onto 10 sectors in two horizontal rows on five sectors in each row.

in zone of type D - in latitude in the low (southern) row 4 °, in the top row 6 °, in longitude 36 °.

Sectors in zones are numbered by single digits in horizontal rows from left to right, starting from the left sector of the top row and finishing by the right sector of the low row (the tenth digit is a zero).

in zones of type A. B and C - by the parallels drawn through each degree, and by the meridians drawn through each 1°30 ', beginning from sector borders; sizes of the square - in latitude 1 °, in longitude 1°30 ';

in zone of type D - by the parallels drawn through each degree, and by the meridians drawn in sector of the low row through each 6 °, in sector of the top row - through each 12 °, starting from sector borders; the sizes of squares in sectors of the lower row - in latitude 1 °, in longitude 6 °, in sectors of the upper row - in latitude 1 °, in longitude 12 °.

Square in the sector is numbered with two digits that correspond to the numbers of horizontal and vertical rows of squares, the intersection of which it is located.

Horizontal rows of sector squares are numbered from below upwards, vertical rows - from left to right. The sequence of digits of numbering of horizontal rows continues for numbering the vertical rows (tenth digit is a zero).

5 4	6	7	8	9	0
3
2
1

The square is divided into nine mean squares into three horizontal rows by three mean square in each row. Numbering of mean squares is made by single digits from 1 to 9, starting from the upper left corner, increasing clockwise, and ending on the square located in the center.

The mean square is divided into nine small squares, which are arranged and numbered the same as the mean squares.

Latitude	Sizes of mean square		Sizes of small square
Latitude	by latitude	by longitude	by latitude	by longitude
From equator to 80° n.l. (zones A, B, C)	20'	30'	6'40"	10'
From 80° to 84° n.l. (low row of sectors of zone D)	20'	2°	6'40"	40'
From 84 ° to 90 ° n.l. (upper row of sectors of zone D)	20'	4°	6'40"	1°20'

The point location on air defence grid is designated with accuracy till the sizes of a small square by a seven-digit number, where the first two digits - zone number, the third digit - sector number, the fourth and fifth digits - the number of the square, the sixth and seventh digits - numbers of mean and small squares. By sending the reports about air situation to local units there is allowed the shortened transfer of coordinates by four- or five-digit numbers without inclusion into the report of numbers of zones and sectors or only numbers of zones.

If it is necessary more accurately to indicate coordinates of the point the small square can be divided by another nine squares (in the dialog labeled as the small squares) in the same order as the mean square is divided into small. In the latter case, the coordinate of the point is indicated by the eight-digit number.

Degree of reduction of coordinates designations in reports about air situation is defined particularly for each division by corresponding commanders of formations and military units depending on a place of a disposition, the notification scheme and other conditions. At the refined transfer of coordinates by eight-digit numbers the shorthand designation is not allowed.

On maps sheets with air defence grid in each sector in full or in part included into sheet of a map, there is digitized one northwest square by the five-digit number denoting the corresponding numbers of a zone (the two first digits), sectors (the third digit) and a square (the fourth and fifth digits). Mean and small squares on maps are not digitized.

Building a grid is possible by map or a set of maps, and also by a tied raster or a set of raster images. The main map or a raster should support possibility of transformation of geodetic coordinates. After dialog start it is necessary to enter a map name onto which air defence grid will be put. If such map exists, all objects will be destroyed on it. Before it on the screen the warning is displayed. Further it is necessary from the drop-down list to choose to what level the air defence grid will be constructed. Below the drop-down list there is the hint, recommending level of construction of a grid, on the basis of the scale of the main map. Thus, in the drop-down list, the corresponding item specified in the tooltip will be automatically selected. Then you can select by what type of objects the grid will be done - by linear or areal. In dialog it is impossible to change the view of objects, but they are in the classifier operator.rsc.

If dialog is correctly filled, the button "Run" becomes available, by pressing onto which you build the grid of air defence.