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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004
2.3.2 Design of application scheme
Application schema is the design drawing (physical model) of
spatial data and is composed of structure and attributes of data,
relation among the data, UML class drawing and definition
documents. As shown in Figure 5, the application schema is
designed by defining the spatial attributes, thematic attributes,
temporal attributes and relation with the land structures taking
into account the use method in the business operation and
relation among the data items based on the extracted data items.
i ibutes to be used A
Information and attribu folication scheda is
Drive way | Area design in a manner to \
Kilo-spot j conform to the use method |
P sm. | based on the extracted
Managing entity A "gata items Features: S
Walk way | Location ii
Kilo-spot Road facilities Example of
Process of establishment road facility
[EEE (EEE A
— I ] Mechanical
| Name of Feature | MH À Walk way Drive way ; facility
SE A +Position
Definition of | [> Location +Area
| spatial attributes . | A }Kilo-spot +Kilo-spot eS
[s P Process Ma tit
erm HE establishment naging eni JET fan
Definition of
| thematic attributes | 1 p N +Type
i
efinition of . Snow
| temporal tetes | Pavement Bridge thawing pipe
/ | Area — s *Position
Relation among *Type *Name nme
i +Time :
[ey i of establishment +History of repair
of establishment
Figure 5. Design of application schema
3. APPLICATION TO DATA PRODUCTION
3.1 Construction of data
We prepared the data according to the “specifications for spatial
data product used for road management operation” decided in
Chapter 3. The plan was drawn up by clarifying the ground
objects and scope for which the data should be compiled and
determining proper procedures for data construction and quality
evaluation. As for the measurement and determination of spatial
attributes, the measurement is done by using either one of site
survey, aerial map or existing map, and the spatial attributes
(point, line, surface) which show the position and shape of
ground objects. The thematic attributes (type, etc.) and temporal
attributes (date of establishment) are determined based on the
existing materials (records, ctc.) and materials of site survey.
Quality is finally evaluated to confirm whether the spatial data
compiled satisfy the quality requirements of data product
specifications. As for the final outcome, the data file is
compiled according to the encoding specifications.
3.2 Quality evaluation
It is the quality evaluation to which the attention is paid in
applying geographical information standard to the data
compilation. It is possible to define the data specification in
detail taking into account the properties of spatial data if the
geographical information standard is applied as stated in the
above. In addition, it is possible to clearly evaluate whether the
compiled data are conforming to the data product specification
by setting forth the quality requirements and quality evaluation
procedures. It means to contribute to the quality improvement
of spatial data.
The quality of spatial data is evaluated by the factors such as
integrity, logical consistency, accuracy of position, accuracy of
time and accuracy of theme. Figure 6 shows an example where
the quality is evaluated according to the quality requirements
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and quality evaluation procedures of “data product
specifications for the management of road facilities.”
Completeness ^ ———— ——-—— ——« Positional accuracy — -
Commission of road À
|
|
|
|
j
Sons ||
facility | |
| Existing maps Data |
If there is any omission or excess in the ground structure
NT ES g e CN.
Whether the position of
ground structures is correct - d
—
Logical CORSiStenCy
Conceptual consistency. Domain consistency
Definition of
Topological consistency
Defined area E
oftrafficlane E
Ascending lane, É "Changing |
changinglane, B lane |
main Jane E
ether there I is any deviation
in the defined areas
Consistency
of phase :
Surface is
composed of
Whether Su tone
among the figures is correct
>>>
SR
4
+
NN
uo
Whether the temporal attributes (date of
establishment and removal, period, etc.)
Temporal accuracy €^ =
MM Whether the thematic attributes (type. name.
Thematic accuracy € 1| extension, etc.) is correct
Figure 6. Quality evaluation
3.3 Compilation of metadata
Metadata means the “data describing the spatial data” which
describes the information such as “when the spatial data was
created,” “which area the data are referring to,” “who is the
manager” or “how it can be acquired.” The metadata are the
data subject to the retrieval of clearinghouse and are playing
important role to promote the distribution of spatial data. It is
recommended never to fail to make the metadata when to
compile the spatial data according to the geographical
information standard.
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4. CONSIDERATION AND ISSUES IN THE FUTURE
4.1 Consideration
We have reported about the application of “geographical
information standard” in the use of information relating to the
road management operation of National Road Office. The
following is our consideration about the result of application.
[Geographical information standard is object oriented design
method and is effective for defining data specification taking
into account the utility.
[! Geographical information standard makes it possible to
handle the properties of geographical information in detail and
is effective defining highly precise data specification.
(The data product specifications conforming to geographical
information standard can clearly indicate the application
schema and quality requirements as well as the quality
specification as the quality evaluation procedures, and are
effective for the quality improvement of data. It is also effective
for the quality control in compiling the data.
[1We recommend compilation of metadata as it contributes to
the improvement of distribution of spatial data.
4.2 The issues in the future
The standardization of geographical information in Japan has
just arrived at the level of practical use and dissemination from
the level of research. Considering the fact that the present report
is one of very few example of application, it is also true that
there are many problems in the use and dissemination of the
