EXPERIENCE IN DIGITAL PHOTOGRAMMETRIC MAPPING 
Jee-cheng WU 
BOX 90569, Taichung 
Taiwan, R.O.C. 
Commission IV 
ABSTRACT 
It is one of new and necessary ways to produce digital maps with computer assisted 
analog stereoplotter and analytical plotter, which are effective tools to acquire geo- 
graphic data. 
In the course of digital photogrammetric mapping, the author makes a 
study of the standard procedure, and emphasizes the preparations for photogrammetric 
digitizing, the digitizing of geographic data, the data conversion and the digital 
data quality evaluation. 
1. INTRODUCTION 
In Taiwan, we are starting the construc- 
tion projects under the Six-Year Nation- 
al Development Plan. From the projects, 
we know that it's a natural tendency for 
digital photogrammetric mapping to com- 
bine step by step the analysis functions 
of geographic information with related 
attributes data and to provide the dig- 
ital maps for decision making divisions. 
After over three years' research on dig- 
ital mapping, the author states in this 
article his experience in making digital 
cartography with digital photogrammetry. 
2. OPERATION PROCEDURE OF DIGITAL 
PHOTOGRAMMETRIC MAPPING 
The ways of operating digital photogram- 
metric mapping depend on terrain, map 
scale, purposes, instruments, accuracy 
requirements, etc., but the operation 
procedure is similar, including the fol- 
lowing steps. 
a) Planning the Production of the 
Photogrammetric Project 
b) Control Point Survey 
c) Anti-airphoto Signal Setting 
d) Aerial Photographing 
e) Pricking 
f) Field Affirmation 
g) Aerial Triangulation 
h) Acquiring Digital Data through 
Stereo Plotting 
i) Field Survey 
j) Data Edition and Compilation 
k) Creation of Standard Exchange File 
1) Arrangement of Result and Documents 
As mentioned above, step (a) through 
step (g) are the same as those of tradi- 
tional photogrammetry, so I don't make 
any statements on them, but put the 
emphasis on step (h) through step (1). 
3. ACQUIRING DIGITAL DATA THROUGH 
STEREO PLOTTING 
When we digitize topographic data with 
computer aided analogy plotter or ana- 
lytical stereo plotter, the following 
steps are usually included: 
248 
3.1 Preparations Before Stereo Plotting 
3.1.1 Definition of Data Structure 
and Feature Code 
According to the digitizing purpose, we 
have to first plan and define the data 
structure to meet the requirement of 
geographical information application. 
The most popular way at present is to 
show the relation among all geographic 
data elements with the hierarchy struc- 
ture. Uniform feature code, which actu- 
ally represents digital geographic data 
through specific alphanumeric code, is 
important for the data exchange and 
transmission among different users and 
the establishment of the map data base. 
Take for example the process standard of 
topographic data recommended by the Min- 
istry of Interior. 
Major Code Category 
A00000000 Control Points 
B00000000 Administrative Boundaries 
c00000000 Urban Plan Boundaries 
D00000000 Cadastral Boundaries 
E00000000 Buildings 
F00000000 Terrain 
G00000000 Public Utility 
H00000000 Vegetative Surface Features 
J00000000 Transportations 
K00000000 Hydrography 
L00000000 Statistical Boundaries 
Example: 
Transportations 
(J00000000) 
Road Railway 
(J1A000000) (J1B000000) 
Roadway Divided Highway 
(J1A010000) 
(J1A020000) 
Planning Road Road under Construction 
(J1A010020) (J1a010030) 
  
Fig. 1 Hierarchy Structure 
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