nearest pixel to that position in the original image. In this 
stage the reference parameters for the used projection 
system must be indicated, which means, ellipsoid, central 
band, etc. The ones used in our case were: 
generating the marginal information to include in 
each one. This information, is compossed with a 
group of objects proceeding from diferents 
sources: 
Projection System 
Transverse Mercator 
Ellipsoid 
International of 1909 
Datum 
Campo Inchauspe 
Scale Factor 
1 
Band Central 
Meridian Length 
0 
CO 
CD 
Projection System 
Origin Latitude 
CD 
O 
0 
False Est (band limit) 
500.000 meters 
False Nord 
0 (zero) meters 
With all these parameters the software carries out the 
Rectification and Georeferentiation in the same step. 
The following stage is the image cutting in sectors of 30’ 
width (in lenght), and 20’ of height (in latitude), according to 
the MGI dispositions, for the 1:100.000 scale charts. This 
cutting is realized following the meridians and parallels 
whose values of latitude and lenght are transformed in plane 
coordinates using the ERDAS Utility/Coordinate Calculator 
command, with the following set of parameters: 
1. - The linear general scheme with MGI format 
and the province surroundings with the quadrillé 
mark, were drown with AutoCAD and converted 
into an object of annotation type using the 
ERDAS module Import/Export. 
2, - Our University Seal was a .PCX file that was 
converted to the .IMG format of ERDAS with the 
same module Import/Export. 
3,- The Magnetic Declination information of the 
center of any chart, the annual variation and the 
declination aceleration, were determinated with 
MAG90 software which, entering the latitude, 
lenght and the ellipsoidic height, allows to 
calculate the indicated information for the day 
January 01 of any year. 
4,- The land use general patterns sheme(charts 
bottom left corner) was generated cutting from 
the images any pattern and adding to them the 
collected information during the recognition 
stage. 
INPUT PARAMETERS 
Projection 
Geographic 
(latitude, Lenght) 
Ellipsoid 
International oi 1909 
Datum 
Campo Inchauspe 
OUTPUT PARAMETERS 
Projection 
Transverse Mercator 
Ellipsoid 
International of 1909 
Datum 
Campo Inchauspe 
Band Central 
Meridian Lenght 
63° 
Projection System 
Latitud Origine 
CD 
O 
o 
False Est (Band Limit) 
500.000 meters 
False Nord 
0 (zero) meters 
5,- The references and all the text boxes were 
generated with ERDAS tools. 
For better ¡lustration, we show a chart reduction 
and an amplificated reproduction of the marginal 
information boxes that completes, any chart: 
Is important to remark that the -63° Central Meridian 
corresponds to the 4 th band in the Argentine Cartographic 
System. During the cuttings it is important to considerate the 
meridians convergence, because any cut is issued with a 
rectangle whose upper left and lower right vertex are 
indicated, having to hold the corresponding cautions when 
realizing this operations with those charts that they are 
placed to the west of the band central meridian, so that 
analizing two or more vertically adjacents charts, holes and 
overlapping are not produced. 
Once accomplished the cutting, we have the image parts that 
conform each chart, then we can start the edition of them