Although some time ago the Geographic Institutes in Latin America officialized the change to wGS84 as a standardized projection, the change in use level goes a bit slow. Actually the projection is always cylindrical and the change hardly implies a Datum change between NAD27 and NAD83, however the implications become more complex than moving the maps a uniform vector. Among the most important reasons that affect standardization are the following:
1. The majority of existing cartography in many Hispanic countries is in NAD27, And little product has been generated in the new projection. Therefore the easiest thing is to not complicate life and use information in the formats that abound.
2. For “cartographic” purposes, It is often unaffected to use both systems, aspect that is harmful because in some cases the information becomes “Painted maps“. However, those of us who work from the municipal approach, such as cadastre, the projection aspect is vital, if you want to manage nomenclatures of cadastral key under the criterion of quadrants; since the grids in both systems are different, which implies that the identity of a property changes if we migrate from one system to another. Additionally most new GPS do not bring all the options of the NAD27 projection.
2. The autonomy that the governmental instances it is affected by the lack of leadership on the part of the regulatory entities in matters of cartography and territorial ordering. Although the official changes to the new projection are known many years ago, in some cases a little more is required than to say it, since there must be inter-agency spatial data commissions that can regulate the uniformity of projection for national management. The loss of leadership in the last century, after the US army has let down its guard, has caused major setbacks in some countries where they have only been left with printed materials or in similar formats, without haste to migrate to technologies for the publication of information according to time.
3. The fact that many computer systems have no problem in Reproject data on the fly It makes standardization not urgent. However it is not enough to reproject, sometimes it is necessary to normalize information, because in many cases what is done is to move the cartography a uniform vector of so many meters to the north and so many to the east, however the reprojection implies much more than that in function of the scale and relevance of the data.
It is possible to complicate or simplify things with Google Earth, Jeje Which reads as follows:
- Normally, the data you import to Google Earth are created with a specific geographic coordinate system, such as the Universal Transverse Mercator (UTM) projection and a Datum NAD27 (Datum Of North America of 1927)
- Currently, Google Earth does not support files that use the NAD83 projection.