Analytical methods and the rest by Independent Models Triangulation. 
The adjustment method used in all cases, was the polynomial block 
adjustment. That is specially suitable for the scale we are working 
with, mainly 1:50000, and the ground control distribution. 
We could say that the evolution of Aerial Triangulation has been con- 
siderable from the last report, when the Aeropolygon method was in 
use. Nowadays only Semianalytical and fully Analytical methods are 
used. 
Some research has been carried out in order to apply Aerial Triangu 
lation procedures to ERTS imaginery. The results were satisfactory 
for the rectification of the images. 
COMMISSION IV. 
PHOTOGRAMMETRIC MAPPING. 
The main achievements in photogrammetric mapping were at 
1:50 000 scale with the completion of about 700 map sheets in all 
types of terrain in the period; with this advance, a total of 1100 map 
sheets are available in this series. 
Mapping at 1:10 000 scale is getting more importance; about 20 000 
square kilometers were covered. 
Increasing attention is being paid to the cadastral problems; the 
main interest has been focussed to the urban aspect, but now with 
the urgent needs of Agricultural Planifications, the rural cadastre is 
getting more and more attention. The use of photomaps (rectification 
or ortophoto) is being tested for cadastral applications. 
COMMISSION VII. 
PHOTOINTERPRETATION AND REMOTE SENSING. 
Intense activity in the application of photointerpretation as a tool for 
resources mapping is going on in Mexico. Among the most important 
achievements we can mention: 
Completion of a Land Use map 1:1 000 000 using LANDSA T imagi - 
nery.