COMMISSION II. 
PLOTTING INSTRUMENTS AND METHODS. 
Equipment. 
The main available equipment reported is formed by: 
24 Precision plotters (A7, A9, A10, C8). 
80 Topographic plotters (A8, B8, B9, Stereosimplex IIc, Kelsh, 
Balplex, PG-2). 
Stereocomparator. 
Point transfer devices. 
Ortophotos (Stereomate, SFOM). 
20 Rectifiers. 
Ww CO Hr 
The acquisitions reported in the period were: 1 ortophoto, 4 preci- 
sion plotters, 12 topographic plotters and 1 rectifier. 
Methodology. 
There are two methodologycal achievements worthwile to be men- 
tioned: 
The first one is that 1000000 square kilometers of 1:50 000 topogra - 
phic map have been made by direct scribing on the altimetric infor- 
mation; the high quality obtained makes not necessary the rescribing, 
only minor corrections of the originals are made. The production 
rate is about 5 square kilometers per hour. 
The second achievement is the development of the methodology for 
Analytical Aerial Triangulation with analogue instruments. The 
results were very satisfactory because the accuracy was about the 
same that is normally obtained with an stereocomparator, and the 
production rate was 200% of the production usually achieved in 
analogue plotters. 
COMMISSION II. 
AERIAL TRIANGULATION. 
The urgent needs for mapping of extense areas of Mexico have strongly 
motivated the use of aerial triangulation methods in Mexico; in the 
last 4 years, about 40000 models were processed, 70% of them using