Previously We talked of the difference between UTM and geographical coordinates, in this post we will explain how to create quadrant maps at large scales for cadastre use.

When it comes to creating quadrant maps in a cover, geographers resemble that it is a work of the gods whereas sketchers believe that it is only duplicating a grid that in many occasions make up orthogonal.

The origin of this grid is the partition of the earth's surface by the meridians and parallels, be careful, you have to choose the reference spheroid, as this defines the dimension of the segments. I'm going to use the example of Honduras, for the purposes of understanding.

The maps are given a reference scale, depending on the printing of these generally in sheets of 24 "x36", so when we use the scale we will be referring to this proportion to which a map can be accommodated, using its horizontal dimension as reference to an 24 "x36" sheet, including spaces for margins.

Honduras is between zones 16 and 17, and the segment P formed by the parallels, the zone marked in orange has six degrees between the parallels. When printing a map of this area, the scale is 1: 1,000,000

It can be seen very well that this orange zone goes from the 84W to 90W meridian and between 8N and 16N so it is a segment of 6 degrees in longitude and 8 degrees in latitude. Also to Change the view To UTM coordinates you can see the angles.

By dividing this area into four parts we have 4 segments of 3 ° by 4 °, the printing of these maps is close to 1: 500,000; This can be downloaded in vector format (kml, shp, dxf, dgn) for different zones from this link.

If that segment is divided into two longitudinally, each of them will be 1 ° 30 'in longitude and 1 ° in latitude. These maps would be printed at 1: 250,000.

Then if one of these regions is divided into three horizontal and two vertical segments, we will have areas of 30 'longitude and 30' latitude, these would be printed at an approximate scale of 1: 100,000.

Then if we divide one of these regions into two horizontal and three vertical segments, we will have areas of 15' longitude and 10' latitude and these are the maps well known as "cartographic sheets" 1:50,000.

Then if we want to take the maps for rural survey 1: 10,000 it is enough that we divide these segments 5 vertical parts of 3' of length by 2' of latitude; Clarifying that according to the latitude that we find, could be divided in 4 x 4, because as it moves away from the equator it is narrowing.

To get 1 maps: 5,000 would be sections of 1'30 "for 1 ', for 1 maps: 2,000 in sections of 36" for 24 "and for maps 1: 1,000 we would divide it into sections of 18" in length by 12 "Of latitude.

If we look, none of them requires rounding, because the corners can be calculated in geographic coordinates and converted to UTM to draw them on the map. To convert geographic coordinates to UTM There are applications.

The ideal is to start from a 1: 50,000 sheet that are well known and calculate the UTM coordinates and then make the partition in AtoCAD. The example shown is Honduras, with its sheets 1: 50,000 on the large grid and 1: 10,000 on the small grid.

Of the nomenclature? ... will be another day.

In this other post a similar exercise is done, with the case of the southern hemisphere, Specifically with Bolivia.

### Golgi Alvarez

Writer, researcher, specialist in Land Management Models. He has participated in the conceptualization and implementation of models such as: National Property Administration System SINAP in Honduras, Management Model of Joint Municipalities in Honduras, Integrated Cadastre-Registry Management Model in Nicaragua, Territory Administration System SAT in Colombia . Editor of the Geofumadas knowledge blog since 2007 and creator of the AulaGEO Academy that includes more than 100 courses on GIS - CAD - BIM - Digital Twins topics.