jeld 
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and 
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0. 
1.5 GIS Oriented Design 
1.5.1 The codes and the cartographic symbol base 
form a system. The codes are correspondent with the 
cartographic symbols. Corresponding code are input 
with setting of the position of points. EPSA will mapping 
automatically by transfer cartographic symbols. 
1.5.2 Setting of layers freely. Using EPSA, maps 
can be divide into any layers freely by different codes. 
It can set suitable corresponding layers for different GIS 
and transfer data into GIS smoothly. 
1.5.3 Establishment of spatial data base. In order to 
further manage and utilise the information of surveying 
and mapping, spatial data base was designed meticulously 
in EPSA.It consists of six structures: point, line, ground 
Object, object, lettering, attribute. Here, “object” 
means a group of ground objects, ie, a lot of ground 
objects merged together for certain purpose. The overall 
artical is called “object”. This design overcomes the 
difficulty on surveying and mapping of certain ground 
objects, and also utilizes the data of surveying and 
mapping. 
1.5.4 The “swallow and spit” function in EPSA. 
It ensures the accuracy of edge connection betwen maps, 
pays particular attention to efficiency, and enables the 
update of former maps at some parts of an area. For 
examples, "spit" the parts of former map which 
required to be updated,then “swallow” the maps of this 
areas surveyed in recent time, and combine it with the 
former maps. 
1.5.5 Interface for GIS. EPSA has taken the interface 
for GIS into account,so it can be used as an important 
data source and data updating method for GIS. 
2. NEW 
IDENTIFICATION AND MAPPING OF AERIEL 
FILM 
In most cases, there are two ways in identification and 
mapping of aerial film at present time. 
1) Using enlarged aerial film identified in field work, and 
METHOD AND PROCEDURE IN 
409 
the idendified photograph is the reference for acquisition 
and ‘mapping by photogrammetric instrument. It is 
generally available in small scale photogrammetric 
mapping. 
2) Using drafting sketch acquisiting and mapping by 
photogrammetre instrument identified in field work, and 
then digitized by digitizer. It is generally available in large 
scale photogrammetric mapping. 
EPSA,a system of acquisitng and mapping in real 
time,has many functions, such as: editting of surveyed 
pattern correction of eaves, surveying of “swallow and 
spit” lettering. The new method and procedure in 
identification and mapping of aerial film when utilized 
these functions is state as following: 
  
data acquisiting 
by analytical plotter 
or sterocomparator 
  
  
  
  
  
data received by EPSA , 
produce digital maps 
  
  
  
i 
install EPSA 
(digital maps is carried on) 
  
  
into portable computer 
  
  
  
  
p 
  
idenficated digital map in field work, 
lettering, correction of eaves,editting, 
  
  
update in real time 
  
  
  
appropriate editting and 
modifying in office work 
| 
  
  
  
  
  
  
  
  
  
drawing GIS 
on paper 
map base 
  
  
  
  
  
  
  
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996