FINAL REPORT OF W.G. IV/4: STANDARDS FOR PHOTOGRAMMETRIC PROCEDURES 
J. Kure, M.M. Radwan 
Associate Professors, Department of Geoinformatics, ITC, 
P.0. Box 6, 7500 AA Enschede, The Netherlands - Commission IV 
ABSTRACT: 
This report outlines the guidelines developed by the W.G. on the establishment and verification of data 
quality standards. The approach followed was to first identify the main production lines used in the 
photogrammetric collection of digital GIS data and then to review all possible influencing factors 
involved. On the basis of these influencing factors and error sources, data quality standards are drawn 
up, which include the elements of data history, positional accuracy, data base completeness, logical 
consistency, data security and data decay rate. 
1. BACKGROUND 
Based on resolution IV/5 adopted at the 1988 ISPRS 
Kyoto Congress, that guidance be drawn up in 
drafting specifications for the photogrammetric 
and remote sensing tools and techniques used for 
the production of data for GIS’s, W.G. IV/4 vas 
set up, with the terms of reference to concentrate 
on: 
a) Specifications for photogrammetric point 
determination, with quality control. 
b) Organising courses and producing lecture 
materials and tutorial papers for the spread of 
knowledge in this field. 
2. MODIFICATION OF SCOPE OF W.G. PROGRAMME 
In the discussion of these Terms of Reference 
within the W.G., the following points were raised: 
- since we are concerned with the collection of 
digital data for a GIS, it is more appropriate 
to speak about standards rather than 
specifications. 
This distinction is particularly relevant when 
dealing with data quality, where the traditional 
map specifications deal with the establishment 
of the data quality requirements to be satisfied 
in a final product, such as a map. The digital 
data quality standards, on the other hand, deal 
with the establishment and verification of the 
data quality actually obtained in the data 
collection process, and it is up to the users 
assessing such data to evaluate its suitability 
for their particular application in mind i.e. 
with standards, the interest lies in 
establishing a true quality label of the data, 
whilst with specifications one is interested in 
setting up numerical thresholds that will allow 
one to achieve a pre-determined quality. 
- Since the term photogrammetric point 
determination is commonly used to describe 
aerial triangulation, which is rather limited in 
its scope, it was felt more appropriate to 
extend the terms of reference to developing 
standards for photogrammetrically collected data 
i.e. also cover the photogrammetric digital data 
collection for GIS’s, etc. 
- In order to be practical, the V.G. must 
set itself a target that can be realised in the 
time available, up to the Washington Congress. 
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The W.G. therefore decided to concentrate on 
data quality standards and not to deal with data 
classification standards and data exchange 
standards. Unlike the other two, data quality 
standards are application independent and are 
thereby suited to a discussion on an 
international level. Furthermore, data quality 
is by itself an important topic, even if its 
treatment only leads to a reduction in the 
confusion in the statistical terminology used. 
- In developing standards, the W.G. would 
concentrate on producing guidelines on the 
establishment and verification of data quality 
standards. Hereby the intention is to assist 
agencies faced with this task and not to try to 
develop a universal standard. 
Considerable work has and is being done in this 
field of data standards throughout the world and 
this has led to publications such as the 
Canadian CCSM National Standards for the 
Exchange of Digital Topographic Data, USGS 
Digital Cartographic Data Standards and the UK 
National Standards for the Transfer of Digital 
Data. This work is not going to be re-shuffled 
here just for the sake of trying to achieve 
universal uniformity, which is also unnecessary. 
What is necessary, however, particularly if data 
is to be exchanged amongst different data bases, 
is that the different agencies involved 
correctly interpret each other’s standards i.e. 
that even if the agencies use different terms 
and definitions, there is at least clarity as to 
what is implied. 
- With regard to the second item in the terms of 
reference, concerning spread of knowledge in 
this field of data quality standards, it was 
felt that this could best be achieved by 
producing the required guidelines and then 
testing these at ISPRS Workshops, arranged in 
cooperation with other W.G.’s also having spread 
of knowledge in their terms of reference. 
As a result, the W.G. finally got underway with 
the revised terms of reference to concentrate on: 
a) Standards of photogrammetrically collected 
data, whereby the results are presented as 
guidelines to be used in their establishment 
and verification. 
b) Presenting these guidelines at ISPRS Workshops 
to be organised in cooperation with other ISPRS 
Working Groups.