vo data sets 
CT storage 
s performed 
JMPAQ 486 
) Laboratory 
format were 
and paper. 
th the sheet 
. The same 
ale. 
)cessing and 
iges was to 
nd | landuse 
able as the 
raphic map 
revision was 
in expansion 
e 1:50,000 
e imageries 
tion for the 
) densities, 
topographic 
on and pixel 
lution much 
ovement did 
sion of some 
e ground of 
5 of the old 
)janchromatic 
ne for areas 
nsive ground 
ig topo maps 
contain a 
ms including 
names. The 
ensive field 
s a massive 
similar to the 
and decayed 
e outer zone 
ideration for 
jenities and 
jat exist are 
uses, making 
3 the former 
ointing with 
imageries had to be very intensive for the purpose of 
accurate representation of the main public buildings 
such as schools, churches, mosques, etc. 
CARTOGRAPHIC PROCESSES 
These included the overlaying of map and imagery 
for compilation, scribing and peeling process for line 
map production and layering of the map information 
on positive line film. 
Overlaying for the Compilation 
The base map to be updated was converted to map 
transparency and superimposed on the transparent 
copy of the imagery to ease transfer of the image 
information for updating the base map. 
Scribing and Peeling Processes 
The scribing was done by having the emulsion of the 
scribe coat removed as a kind of engraving, with the 
result that the line produced is more stable and finer. 
The phonograph needie was very effective for 
maintaining a very stable line quality. Peeling 
removed an area for screening to present areal 
features. These techniques were applied in drafting 
the line and areal information respectively. 
Layering of the Map Information 
Conventional topographic map production is done in 
layers of map information. At the scribing and peeling 
stages the information layering is organized sheet by 
sheet. For our case, as it is in other standard 
processing, the layers were organized according to 
the colours of the final maps (See Table below) into 
five layers for various conventional classes or groups 
of features. 
Photographic Processing of the Layers 
The scribed and peeled sheets were combined for 
each thematic colour and photographically processed 
using contact printing method. It involved first of all 
obtaining a line film negative, duffing out the 
anomalies and then reproducing a positive 
transparent original of each colour theme. It was this 
product that served as the digitizing document. The 
advantage of the positive transparent line film is that 
it facilitates high definition digitizing. 
The stages of production of the digitizable product are 
graphically presented in the Figure of the annex, for 
21 
the 1:50,000 series. The same processes were 
followed for the 1:25,000 series. 
Table showing layered information features 
  
  
Black colour Black Text, frame lines, 
planimetric features like 
roads, transmission 
lines, etc. 
Contour lines, other 
landform features, rock 
outcrops, etc. 
Brown colour 
Blue colour Hydrographic lines, lake 
borders, grid lines and 
grid values, etc. 
Red colour Road in-filling for 
principal routes, etc. 
vegetation, forest 
reserve, etc. 
Green colour 
  
  
Digital Map Production 
For fidelity reasons the digitizing took off using the 
original transparent layers prepared in the drafting 
stages. Within the ARC-Info starter kit, ARCEDIT 
provides all of the facilities for digitizing coverages 
with a highly comprehensive set of graphic editing 
commands. Locational as well as descriptive 
(attribute) data can be edited and manipulated. 
For a more detailed explanation, the transparent 
layers containing roads and buildings for example 
were digitized via a coding system to differentiate 
between different types of roads and buildings and 
the attribute data entered in the attribute database 
which is linkable with the spatial database. This same 
process is valid for all different kinds of information. 
Once all data, both spatial and attribute, had been 
entered and all editing realised, the map design 
process started. This involved entering the legend, 
titles and text. 
Finally hard copies of the produced maps were 
plotted with a pen plotter. Digital back-ups were 
stored on diskettes to be delivered along with other 
products. 
All the contour data were digitized during the 
digitization process with the corresponding elevation 
data attached. These data (in vector format) were 
rasterized according to elevation coding. After 
rasterization, the ARC-INFO isolines generation and 
interpolation modules created a digital elevation 
model (DEM) which were stored on diskettes. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996