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responses to circular letters, with some 80 respondents
registering their interest over the four-year period. The
lack of intervening meetings has led to very strong
programmes for both the symposium and the Congress.
It seems likely that the Working Group could support at
least one Workshop devoted specifically to Map and
Database Revision during the next session. Potential
organisers should note that similar groups exist within
other international or regional organisations such as ICA,
CERCO and OEEPE so cooperation is clearly desirable
and joint meetings should be considered.
This paper is confined to reviewing only the Congress
papers offered to this Working Group, although some
relevant material published elsewhere during the period
is naturally also cited. It is certain that there will be
many contributions to other working groups, especially in
Commissions Il and lll, which are of lively interest to the
members of WGIV/3. Indeed the present “horizontal”
Commission structure, with layers of activity from initial
data capture onwards, requires those who are interested
in a particular "vertical" theme (for example the whole of
topographic mapping from sensor to user) to be involved
in the affairs of almost all of the Commissions. This is
unduly expensive even for those with institutional support
and prohibitive for those without sponsorship; thus it is
certain that even the chairman of this working group has
overlooked numerous relevant contributions during the
past eight years. The structure is also inefficient in terms
of the exchange of ideas and of the cross-fertilisation
between researchers, theoreticians and practitioners
which in my view was the main justification for the
continued survival of the vertical Commission structure of
ISPRS. It is hoped that the inevitable overlaps in this
Congress programme, the impossibility of one delegate
attending all of the sessions relevant to his interests, and
the dispersal of related papers among numerous
volumes of the archives, will stimulate the reopening of
the debate on future ISPRS structure which yielded
inconclusive results in the 1988-92 session.
2. REVIEW OF CONTRIBUTIONS TO THIS CONGRESS
At the time of writing, the detailed programme for the
Congress is not yet available, but | have seen all of the
extended abstracts offered for this Working Group and
have advised on how they should fit into the programme.
The first session, whose proposed title is "Map Revision :
Where are we now ? (Progress and Practice 1992 - 96)”,
readily embraces papers from a range of national
mapping or similar organisations: van Asperen (The
Netherlands), Armenakis (Canada), Müller (Germany)
and Krishna (India) are all using or proposing softcopy
approaches. The emphasis from the Netherlands is on
management, rather than technicalities, to ensure
efficient routine operations. The emerging consensus is
that mono-plotting, from a digital orthophoto, is the cost
effective way forward. Peled (Israel) reports on
developing national mapping procedures as well as his
own research towards semi-automated revision based on
the intelligence embodied in the existing database.
Meanwhile Sehnalek (USA) reports from the private
sector on procedures which closely follow those reported
in earlier years by this author (Newby, 1990).
599
The theme of automation is taken up in earnest in our
second session “Change at the Millennium : Is
automation possible ? (Ongoing developments, with
total automation the ultimate goal)”. In his invited paper,
Woodsford (UK) offers us a thoughtful and thought-
provoking discussion of update philosophy and
paradigms, with special emphasis on the importance of
maintaining database integrity. Two papers from
Germany, offered by Englisch ef al (Munich) and Anders
et al (Stuttgart) report on important research into
automated feature extraction, the former emphasising
medium scale (topographic) data (ATKIS) and the latter
very large scale (cadastral) data (ALK). Steps towards
the automation of change detection or feature extraction
for various themes or scales are also reported by
Masaharu (Japan), Shi and Shibasaki (Japan), Johnsson
(Sweden) and Lin (China).
There are also numerous contributions which fit well into
a possible third session: “Graphic Revision and Digital
Update - Field, Office and User. (Diverse needs, diverse
processes : where should photogrammetry fit in ?)” Mills
(UK) breaks into true digital airborne imagery (as
opposed to scanned conventional aerial photography), in
experiments using a very small format digital camera for
local map revision. This offers the prospect of a shift in
the balance between field and photogrammetric surveys
for change on small sites. Grozdeva (Russia) follows
the same principle as Mills but proposes appropriate
technology of conventional small format photography
taken from a microlight aircraft for the revision of small
towns, presumably in a country where there is no official
bar on the use of microlights for business purposes.
Other varied contributions cover combinations of aerial
imagery with SPOT (Naithani, India) or with terrestrial
photography (Crosilla, Italy), both of which are
presumably more feasible in the digital era than in the
past. Solutions at varying levels of technology are also
proposed by Julia (Argentina) and Ramirez (USA).
Standards, a topic neglected by ISPRS WGs, are
addressed by van den Heuvel (The Netherlands). Finally
| will cite Tempfli (The Netherlands) whose discussion of
scale, resolution and scanning parameters may help
users to ensure that digital image technology matches
the performance to which we are accustomed. Along
the way he gives a notable demonstration of the benefits
of stereo imagery, a point possibly yet to be fully
appreciated by the proponents of digital mono-plotting.
Several of the papers cited above will receive their
exposure in the Congress Poster Sessions, along with
many more which bring fresh perspectives to the same
themes. | will allow all of these authors to speak for
themselves through their presentations in Vienna and
through the Congress Archives, but now offer a
commentary on the current status of map and database
revision and on work published earlier in the 1992-96
session of ISPRS.
3. THE FRAMEWORK FOR DEVELOPMENT
| was recently asked to contribute a paper on “digital
images in the map revision process” for the special
Commission IV issue of the International Journal of
Photogrammetry and Remote Sensing (Newby, 1996).
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
