key in the digital future administration of Denmark. The National
Survey intends to incorporate the address theme in the data base,
if a customer owns this theme.
5. PRODUCTION
In November 1992 the board of directors of the National Survey
decided to establish the database, if as much as possible of the
existing data was reused. This was partly a political descision and
not an ideal solution, since tests had shown that updating old data
was expensive and difficult, and most of the existing map data
were old and not updated. New tests had shown that this bad
condition of the existing map made it less expensive to produce
new map data than to update and upgrade existing databases.
Negations between the National Survey and the data owners for
more than one year once again failed to set up a contract to define
the conditions on which the National Survey could use the
existing map data. One important issue on which the negotiations
failed were copyright terms. The consequence of this missing deal
is that more than two thirds of the rural areas are to be plotted
again, although there exists digital map data covering these areas.
EU tendering
The objective of producing the total database within five years
would demand external production and properly the use of
production capacity outside Denmark. The total project is
estimated to cost more than 100 million Dkr. Contracts of this
magnitude has to be put out for tender. The EU has set up rules
for this. When one has learned these rules, they are quite easy use.
In January an advertisement in the Official Journal states the
approximate total value of tenders the National Survey intends to
advertise during the year. Referring to this time limits can be cut
to a minimum. The kind of tendering chosen, is the one using
prequalification, which means that companies asking for a pre-
qualification has to prove to the National Survey that they can
handle the job. Normaly the National Survey will prequalifie five
companies. To our surprise many companies do not know the
rules and referring to the prequalification note ask for tender
material. They will get a short letter stating the rules. Having run
six tenders we can say that companies all over Europe ask for a
preficalification in despite of that all contract material, standards,
and specification are written in Danish.
To handle production the total area is divided into seventeen
areas. That means that the areas in average is approximately 2500
km? and normally makes one tender. Dependent on topography
an area is futher divided into stages - normally four. If the
National Survey has no access to the data covering the rural areas,
the production is specified as mainly as photogrammetric produc-
tion else as mainly upgrading existing map data. Before the
advertisement the National Survey will contact the local munici-
palities and ask if they have data for sale. If they have they are
asked to send the data to the National Survey for checking.
Dependent of the state of the data the data owner will get an offer
from the National Survey. The price will be strongly dependent of
wether data are in the new and wanted standard, the time of
plotting/up-dating, and the number of hectares for sale. The
National Survey has set a limit of 500 hectares for the smallest
area to buy.
The aerial photography needed for production of TOP10DK is not
parts of the tender.For the updating of analog maps aerial
photography covering about 20% of Denmark is taken every
spring according to the areas to be updated. These areas will, if
392
necessary be expanded to serve the production of TOP10DK. The
National Survey will provide diapositives and contact prints of the
aerial photography covering the area to the producer. The aerial
photographs provided are scale 1:25.000 black and white wide-
angle photographs. Besides these photographs a test area with full
control is provided. This makes the producer able to put up a
model and try plotting using the FK-standard. The test area is not
representative for Denmark. It has been chosen to cover most of
the types of areas and features to be plotted.
Production Flow
The flow in the production is as follows: aerotriangulation, test
plotting, plotting according to FK-standard, and upgrading to
TOP10DK standard. .Between deliveries a control is carried out.
The producer is not allowed to carry on to the next part of the job,
before he has got an acceptance of the delivery to The National
Survey.
Control. To get a contract the producer must establish a system
for quality control, not necessarily ISO9000, but some procedure,
to convince the National Survey that quality control will be
carried out. The demand is put up to ensure that quality control is
not one-sided put on the National Survey.
Aerotriangulation: The type of areotriangulation asked for is
bundle adjustment, but also anblock is accepted. If the producer
uses a program that is not internationally recognized, he has to
make a test calculation, prove to the National Survey that program
does work. Regardless which program the producer uses, he must
deliver picture coordinates (not model coordinates) to The
National Survey. For control coordinated natural points such as
church, towers, chimneys, and so on, are delivered. The demands
are internationally recognized demands - one coordinated point
for every 2-times basis on the edge of the block and one for every
four-times basis inside the block. If the number of control points
recognizable in the models does not fulfill the demands, the
producer himself must establish more points. Height control is
supplied with provisional x and y coordinates, in order to make it
possible to put the measuring mark on the ground in an analytical
plotter. The number asked for are tree points in every model on
the border, and one per model inside the block. The number of
height control points supplied is sufficient to meet the demands.
Plotting of test area. While the aerotriangulation is prepared and
measured, the producer has to make a test plot and send it to the
National Survey for acceptance. The problem is to ensure that the
different operators have reasonably uniform understanding of the
plotting standard. Having seen the plotted test area the National
Survey normally invites the producer to visit the National Survey
and have an assessment of the test plotting.
Some producers need more than one delivery to achieve accep-
tance and permission to continue with the proper plotting.
Plotting of FK-data. The area is divided into stages, usually
between three and five. The producer has to deliver data divided
into two times two km? for approval. It makes data handling much
more easy and calculations of completeness and topology much
faster when data is delivered in such small areas. In the beginning
of the whole project it was up the producer to choose the software
tools to be used in the control phase before delivery to the
National Survey. Experience has shown that this caused much
work at the National Survey - many errors were found and had to
be corrected. In fact there existed very little of this kind of
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
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