13.- Are you revising by : 
[ - the use of terrestrial methods (like plane table) ? 
E 1 - the use of rectified photos ? 
[1 - the use of orthophotos ? 
[] - the use of stereoplotting ? 
[1 - the use of a special instrument, like the double projector, the zoom transfer scope ? 
[ ] - the use of space data (Skylab, ERTS, etc.) ? 
Please indicate which instrument is employed. Enclose a description of it when it isa special 
new device. If there are different devices used for the various types of maps you produce, please 
indicate that below. 
Please indicate the scale of the photograms employed for the revision, and the characteristics 
of the film (black and white, colour, etc. ). 
Please indicate if you utilize informations from other sources (various maps, urbanistic plans, 
data from public agencies, etc. ). e 
14. - Which method is used for the complete production of a revised map ? (Description in 
telegram style). 
Example : Map type n? 3 - scale 1:10 000 - in old map changed lines are scratched - of new 
part orthophotos are produced new guide produced and old unchanged lines etched into new guide 
on scribing material -new lines scribed - diapositive of scribed map - names added - printing 
plate - offset printing - one colour map. 
15.- Are you using the materials and/or instruments mentioned in the answer on question 13, 
only for the revision of a base map, and are the maps derived from the base map revised with 
the help of the updated base map ? 
Or are you revising each map separately with the use of the materials and/or instruments men- 
tioned in question 13 ? 
In which sequence are the produced maps revised ? 
Example : first base map 1:10 000 
then simultaneously 1:25 000 and 1:50 000 maps 
1:250 000 map separately in special revision interval. 
16.- What is in your opinion the decrease in accuracy of the map after each revision ? 
Do you use special methods for the determination of the accuracy of the revised parts of the maps ? e 
17. - Do you apply, in relation with question 16, a system for total renewing of a map ? So for 
instance after three revisions a map sheet has to be produced completely new. 
18. - Do you use a rule for taking the devision to produce a map completely new in relation to the 
costs of revision and those of new production ? 
Example : when more than 60 % of the total surface of a map has to be revised it is more 
efficient to produce the map sheet completely new. 
19. - What is the advantage in production time when you revise a map in comparison with a com- 
pletely new produced map ? Please give your answer for each map type separately. 
20. - Do you apply special cartographic techniques when you are revising the maps ? 
Example : only for map revision the transfer of symbols, lines, roads and names is applied. 
21. - Is your Agency conducting or planning studies and experiments to improve the revision pro- 
cedures and/or devices and materials ? Please specify them. 
22. - Do you deem that some particular study or experience in the revision area is desirable ? 
Please specify it. 
23. - Do you hope that in the next year some important improvement in the revision area will be 
achieved ? In what sector. 
24. - Remarks concerning map revision not covered by questions mentioned above.