4. AERIAL TRIANGULATION 
Project area was divided into 21 Blocks /3/. Each 
block consisted of approximately 300 models. For 
aerial triangulation and for digital mapping, 60% 
forward overlapped photographs were selected. 
Tie points were identified from natural objects 
such as corner of buildings and ends of lines 
drawn on the roads or very sharp objects. Aerial 
triangulation measurements were made on the 8 
Inter Map Analytical (IMA) instruments, using 
stereocomparator mode. 
Before measuring some informations had to be 
enteredinto the data base. This included project 
information, camera information, fiducial mark 
coordinates, block, strip, photograph and model 
informations. After measuring fiducials, 
adjustment of inner orientation was performed by 
conformal transformation with 4 parameters. 
Residuals were kept below 10 micrometers for 
relative oriantation, after 9 parallax points had 
been measured. Tolerance of residual parallaxes 
was 5 micrometers. Approximately 10 control points 
in each model were measured. Root mean square 
error was below 3 cm. 
For aerial triangulation adjustment, the  PAT-MR 
(PC Version), "Block Adjustment with Independent 
Models" program has been used. Each block was 
adjusted separately. 
5. DIGITAL MAPPING 
5.1. Hardware and Software 
During Photogrammetric Digital Map Production, a 
system configuration described in /1/, was used. 
The main part of hardware, is a dual processor 
Intergraph 252. The communication between the main 
computer and the peripheral units is provided 
through ETHERNET. The disk capacity is 2 GB and 
core memory is 32 MB. The operating system is VMS. 
8 IMA, 2 WS, IBM PC/2 and plotters are connected 
to the Local Area Network. 
The software used on the system is as follows: 
- VMS Operating System 
- IMAN, IMAP for stereoplotters 
- IGDS Interactive Graphics Design System 
- DMRS Database Management Retrieval System 
- IPS Intergraph Plotting system 
- ICS Interactive COGO System 
- ETI Electronic Theodolite Interface 
- GNA Geodetic Network Analysis 
- PAT-MR/PC Aerial Triangulation Adjustment 
- ATP Aerial Triangulation Package 
- DTM Digital Terrain Modelling 
5.2. Digitizing 
8 IMA analytic Stereoplotters are used for 
digitizing feature coding mode. 
With this aim, a Turkish "graphics font" and a 
symbol library which is within the national 
standards was created. All the necessary data were 
provided for the operators. 
The topographic TOP-File and planimetric  PLN-File 
are digitized and coded with corresponding symbol 
library. They are buildings and structures, 
boundries, roads, tracks, railways, lines, masts 
and poles, water drainages and coastal features, 
vegetations etc. During the “Feature coding? the 
topographic and planimetric data were stored in to 
63 layers in the Intergraph system. 
Digitized maps are plotted and transfered to the 
quality control. 
246 
5.3. Field Completion 
Field completion had been performed by survey 
teams equipped by Zeiss Elta 3 total stations. 
Field completion planned and performed; based on 
the editing request. Data collection in the field 
had been coded while data was recorded. Than the 
data was transferred to a PC and converted to IGDS 
graphic design files automatically. 
5.4. Editing 
An editing request was prepared per model for 
field completion. 
Field completion was done on the editted file and 
final form of the digitized model was obtained. 
Editing process was carried 
workstation. 
out daily on the 
5.5. Quality Control 
The quality control department checked the 
cartographic quality and completeness of the 
digitized models. By using the final form of the 
models, maps were extracted automatically. The 
final maps were derived form the digital data by 
automated plotting and produced according to 
national standards. 
The quality and control tests of the produced maps 
were carried out by the team in which the authors 
of this paper participated. The results are given 
in /3/. 
6. ISTANBUL LAND INFORMATION SYSTEM (ILIS) 
Since the urbanization development is faster than 
planning it is necessary to make use of all the 
possible technology in urban management. 
Municipality began to implement a Land Information 
System in Istanbul (ILIS). The aim of this system 
is to perform automated mapping for attribute data 
processing, spatial and geographic analysis and 
for management of properties and demographic 
informations/2/. 
The purpose of this project is to have a database 
system with graphic and non graphic parts which 
will work connected to each other. For graphic 
part, the base maps had been developed by using 
aerial photogrammetry. Large scale photographs for 
940 km? were taken and stereo plotting had been 
completed. The non-graphic information had been 
collected and entered into the computer for only 
pilot project area. 
7. EXPERIENCES ON DIGITAL MAPPING AND LIS 
This part comprises of a brief list of the 
experiences in connection with large-scale digital 
mapping and LIS. 
7.1. Organizational Aspect 
There were some organizational problems since the 
project area was too large and since it was the 
first national experience. 
According to us, updating was an important 
problem, since the flight was made only once, 
covering the whole area. It might have been better 
if the digitizing process had been distributed to 
more than one contractor or the flight had been 
made step by step. 
The members of the project working team gained 
  
  
  
  
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