However, photogrammetry has a number of limitations 
and is not always effective. For example dense conifer 
forest, deciduous forest in leaf, swampland of tall 
grasses and featureless terrain such as sand dunes 
can be mapped in more details by ground survey 
techniques. Furthermore there is no substitute for on- 
site inspection of terrain features, especially in large- 
scale mapping of built-up areas, where a considerable 
volume of underground detail and paved surface is 
encountered. 
In addition, with the evolution of GIS there is a need 
for descriptive information that can be acquired only in 
the field, e.g., usage of building - commercial, industry, 
residential or needs for data verification in the field to 
ensure greater thematic and positional accuracy. 
For these reason there is a great demand for field 
completion in the process of producing high quality 
large scale databases. 
The basic objectives of field completion are: 
- to select information from areas which were obscure 
at the photogrammetric workstation. 
- to complete thematic classification and to add 
supplementary data. Some users may require the 
inclusion of a specific type of information in their 
geographic database (e.g., identification of electricity 
network elements and collection of their attributes, 
classification of buildings according to their usage and 
number of floors, etc.). 
- to verify that the map conforms to accuracy 
requirements. 
In this paper we are proposing a new approach that 
will make field completion work more efficient, cost 
effective and less error pron. The use of spatial 
analysis techniques allows the identification of areas 
to be completed, optimization of field completion 
missions --routing, selection of methods and 
instruments, costing, etc.-- and eventually provides the 
necessary quality indicators. This has been achieved 
utilizing GIS/CAD software tools. 
2. INTEGRATION OF GIS, PHOTOGRAMMETRY 
AND FIELD COMPLETION 
The creation of a geospatial database is typically a 
multistep process where GIS with its spatial analysis 
functions and different types of data are involved. 
Figure 1 illustrates the process and the various stages 
for its creation. 
We will describe how we integrate those phases to 
one work flow with special attention to the new 
modules. 
144 
Our approach concerns mainly with the last stages C, 
D and E considering that the initial spatial database 
has been created in the stages A and B. 
A. Planning - The process starts when the client 
approves the answer to his request for proposal 
(RFP). At this step the requirements should fully be 
analyzed and categorized. Some demands can be 
achieved only with field completion, whereas others 
can be satisfied with data collected by 
photogrammetric means. 
The planning stage also includes: 
- detailed schedule with missions list and completion 
time. 
- designing of a photogrammetric flight configuration 
- translation of the specification into detailed 
instructions 
- preparation of a data collection menu --table of 
symbols, linetypes etc. 
Customer Specification 
A | | 
Î i 
| Requirements analysis & general working plan i 
EEE T Eins ith | = I rm EL. UE 
| ontrol Survey 
| 
| 
| Photogrammet Triangulation 
orientation 
  
  
  
  
   
Database structuring and analysis 
Tu. 
ysiation le Len 
To Mon: Work plan & Uncertainty map: 
Manually input 
Trees & vegetation 
Relief displacement 
i a ces qe Shadow areas 
Lee CE NN HELLE” Different sources | 
D 
  
Special requirments.--- "_ ere: 
e poc dig Field completion ; gr 
Data insertio nee 5 ..... New concept 
ess sea MS Standard procedure 
E Ma x 
” Quality estimation {1 Maybe improved 
[es Next step 
  
  
  
  
  
Figure 1 : Spatial database creation 
B. Data collection - This is the "indoor" -office - data 
collection stage, it is initiated and directed by the first 
phase of planning and preparation. The collection of 
photogrammetric data and data from other sources is 
done at this stage. 
Collection of data from other sources consists of two 
steps: 
- gathering of maps and information from the archives 
of related organizations --Municipality, Electricity 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996