Technical aspects of data acquisition and display
Experiences from ENC production
Hydrographic offices, including the AHO in particular, have been aware
for some time of the need for them to position themselves to be able
to generate ENC, raster and paper charts products from the single
moderated source data set. They are painfully aware that the data set
must be maintained, as must be the products.
So marine cartographers producing ENCs must focus on new ways to
present chart information. Paper products have tolerated regional differences in presentation. The dream of a single worldwide ENC coverage
and the rigid demands of computer systems required to run these ENC
databases means that myriads of minor differences are intolerable. No
longer is the chart compiler able to have some determining role as to
how some “feature” might be depicted, or even how far it might be
displaced in position for aesthetic cartographic presentation, but she
must be faithful to the “object”, describing it and its relationships
precisely. Thus, we are starting to see a shift in cartographic thinking
here from the subjective to the objective. Subjectively defined graphic
presentation is giving way to precisely defined and comprehensively
described real-world object. Presently it remains a matter of degree.
There neecls to be realised a changing view of data and the synergy
that modern computers unleash for others such as environmentalists,
researchers, legislatures, law enforcers, searchers and rescuers, coastal
zone managers and so on. This list is by no means exhaustive but
illustrates a largely untapped demand for hydrographers data. It also
serves to make the point that the marine cartographers’ responsibilities
are shifting away from “just” the mariner. As expert interpreters of the
hydrographic and navigational clata, cartographers are inexorably repositioning themselves and their professional role and obligation to
society. If this is interpretecl as drawing a long bow then consider the
scramble for interpretive advice arising from the requirement for nations
to define their various offshore zones!
Any cartographer who has worked for a major map or chart-producing
agency will be aware of the push for minimising effort for derived
mapping. The push continues ancl is almost achieved, conceptually, in
the object oriented marine world. However, the mind processes of the
cartographer as he defines objects are simultaneously spanning all
possible uses of that object for a myriad of possible uses. So the mind is
moving here from the particular (this scale, this use, this presentation)
to the general (all possible scales, all possible uses, all possible presentations). The mariner, at sea, on a cramped bridge, with terrible
visibility, with immense responsibility, unstoppable momentum and
almost certain dependency on electronics, is mterested ultimately in a
fundamental binary equation - go or no go! The mariner is now able
to relate precisely and absolutely to the real world in real time. A realisation of this must be uppermost in the mind of the cartographer
interpreting the data in the comfort of an office, particularly when
making “decrees” as to issues such as usage, quality, relative accuracy.
143
Experiences from ENC production
Hydrographic offices, including the AHO in particular, have been aware
for some time of the need for them to position themselves to be able
to generate ENC, raster and paper charts products from the single
moderated source data set. They are painfully aware that the data set
must be maintained, as must be the products.
So marine cartographers producing ENCs must focus on new ways to
present chart information. Paper products have tolerated regional differences in presentation. The dream of a single worldwide ENC coverage
and the rigid demands of computer systems required to run these ENC
databases means that myriads of minor differences are intolerable. No
longer is the chart compiler able to have some determining role as to
how some “feature” might be depicted, or even how far it might be
displaced in position for aesthetic cartographic presentation, but she
must be faithful to the “object”, describing it and its relationships
precisely. Thus, we are starting to see a shift in cartographic thinking
here from the subjective to the objective. Subjectively defined graphic
presentation is giving way to precisely defined and comprehensively
described real-world object. Presently it remains a matter of degree.
There neecls to be realised a changing view of data and the synergy
that modern computers unleash for others such as environmentalists,
researchers, legislatures, law enforcers, searchers and rescuers, coastal
zone managers and so on. This list is by no means exhaustive but
illustrates a largely untapped demand for hydrographers data. It also
serves to make the point that the marine cartographers’ responsibilities
are shifting away from “just” the mariner. As expert interpreters of the
hydrographic and navigational clata, cartographers are inexorably repositioning themselves and their professional role and obligation to
society. If this is interpretecl as drawing a long bow then consider the
scramble for interpretive advice arising from the requirement for nations
to define their various offshore zones!
Any cartographer who has worked for a major map or chart-producing
agency will be aware of the push for minimising effort for derived
mapping. The push continues ancl is almost achieved, conceptually, in
the object oriented marine world. However, the mind processes of the
cartographer as he defines objects are simultaneously spanning all
possible uses of that object for a myriad of possible uses. So the mind is
moving here from the particular (this scale, this use, this presentation)
to the general (all possible scales, all possible uses, all possible presentations). The mariner, at sea, on a cramped bridge, with terrible
visibility, with immense responsibility, unstoppable momentum and
almost certain dependency on electronics, is mterested ultimately in a
fundamental binary equation - go or no go! The mariner is now able
to relate precisely and absolutely to the real world in real time. A realisation of this must be uppermost in the mind of the cartographer
interpreting the data in the comfort of an office, particularly when
making “decrees” as to issues such as usage, quality, relative accuracy.
143