for updating digital map from the DBMS and its 
applications to the current circumstances of 
large scale maps in Egypt. 
It is cleared that the current used approaches for 
updating digital maps depend mainly on the digitiz- 
ation process for the detected changes. This can be 
generally be accomplished using a stereo-plotter 
and a manual or automatic digitizer. In addition 
to the high cost and time consuming required for 
making such digitization, the process of detecting 
the changes especially in the case of using a new 
photo approach requires professional skills for 
making such detection. Moreover, these approaches 
take also a lot of time in its lengthy graphic 
technique which eventually leads to increase the 
updating cost of the required skillful personnels 
or the equipments that make such updating. With 
the recent and rapidly increasing capabilities of 
all types of computers and database technology, 
the drawbacks in the above mentioned approaches 
can be overcome by using an alternative technique 
to make the updating process from the DBMS and 
using a couple of AMLs routines (option 5 & 6 in 
the developed package). 
The basic adea of the proposed technique for 
updating digital map data from the DBMS comprises 
of two stages; updating the topological attribute 
file (AAT)fiLe using the DBMS INFO. Then applying 
these updating within the geometric attribute file 
using a couple of AMLs in the AUDIGMAP.ASU 
package. The first routine is used to transfer the 
coordinates from the geometric attribute file to 
the AAT file while the second routine is used to 
produce the final updated map. Since each map 
feature has an internal number assigned by ARC/ 
INFO software and stored in both the geometric and 
topological attribute files, the developed techn- 
ique takes advantage from this property in the 
process of transferring the coordinates to the AAT 
file and then updating the old geometric attribute 
file. The main scheme of the proposed technique is 
illustrated in figure (4). 
U 
= 
= 
— 
<< 
ea 
a 
    
  
   
UPDATE INFO FILE 
NEW INFO FILES 
    
  
AAT FILE 
           
    
   
ROUTINE |! 
SYSTEM FILE 
ID XY 
ROUTINE 2 
  
EXISTING MAP 
UPDATED MAP 
        
  
Figure (4) "The Main Scheme of the Developed Technique" 
USER INTERFACE 
WITH COORDINATES 
   
UPDATED AAT 
DROP COORDINATES 
  
  
64 
APPLICATION AND RESULTS 
Each map feature class in ARC/INFO (point, line, 
polygon) has an associated feature attribute 
tables, i.e., AAT and PAT for line and polygon 
coverage respectively in the DBMS INFO. Each 
table defines the topological attributes for all 
features of the same class in the coverage and 
there is a record for each individual feature, 
[Morehouse, 1989]. The proposed updating technique 
is tested here, just for demonstration only, by 
adding a record and deleting another one in the 
AAT file and then applying the corresponding 
changes in the geometric attribute file. To make 
it clear, adding a new line represents the crite- 
ria of the added record and deleting the line 
represents the deleted record using the developed 
routines. 
In order to apply and examine the proposed 
updating technique, a small part of the pilot 
area under investigation, which suffices our 
purpose here is selected and shown in figure (5). 
The sahded area with a User-Id = 990 will be 
divided into two parcels with a line has a User-Id 
=2000. The two adjacent shaded areas (with User-Id 
1230 & 1270) will be merged to constitute a new 
large one with a User-Id = 500 by deleting the 
record in the AAT file representing the inter- 
mediate line that has a user-id = 211 between the 
two parcels. 
The updating of the AAT file is made manually 
using the keyboard of the Micro-Vax workstation. 
the updated information isa list of coordinates 
and IDs for the updated map features that result 
from the data collector of the total station or 
any other updating sources that can give the coord- 
inates of the updated map features. ARC/INFO 
users recognize that coverage s graphics are 
maintained separately from the user accesable 
topological attribute database (INFO files). 
Accordingly, any topological attribute updating 
(adding records, deleting records,..) can not be 
interpreted as graphics results. Thus, the devel- 
oped technique allows updating to the geometric 
and the topological attribute thráugh the DBMS 
(INFO) without low level binary management of 
the graphic files. 
The proposed technique is carried out using a 
couple of AMLs routines and allows the coupling 
link between the INFO and the ARC cartographic 
package to be managed entirely by the high level 
of the ARC routines. The routine (1) used in 
this study concerns with transferring the coord- 
inates from the old geometric attribute file for 
the unchanged arcs to the updated AAT file and 
creating a Vax/Vms file containing the coordinates 
and the Ids for the unchanged arcs and new arcs in 
the updated map. While routine (2) concerns with 
reading the resulted system file and producing the 
updated map. Figure (6) indicates the results of 
applying the developed technique on part of the 
pilot area under investigation. From this figure, 
it is cleared that as a result of applying the 
developed technique and making the updating 
specified in the AAT file, Three polygons are 
identified with IDs equal 990, 9900 and 500. 
POTENTIAL AND FURTHER CAPABILITIES 
OF THE DEVELOPED TECHNIQUE 
The developed technique has noticeable potential 
concerning digital map updating. In addition, it 
has been found that it can encompass further