International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
THE IRANIAN NATIONAL GEODATA REVISION STRATEGY AND REALIZATION
BASED ON GEODATABASE
M.Haeri', A.Fasihi, SM.Ayazi
National Cartographic Center of Iran (Khorasan Branch), 61 Vakil abad Street, Vakil abad Blvd., P.O. Box 91775-
1619, Mashhad, Iran - morihaeri@gmail.com, fasihi.ali@gmail.com, sma@ayazi.ir
Commission IV, WG VIII
KEY WORDS: GIS, Geodatabase, revision, spatial data
ABSTRACT:
In recent years, using of spatial database for storing and managing spatial data has become a hot topic in the field of GIS.
Accordingly National Cartographic Center of Iran (NCC) produces - from time to time - some spatial data which is usually included
in some databases. One of the NCC major projects was designing National Topographic Database (NTDB). NCC decided to create
National Topographic Database of the entire country-based on 1:25000 coverage maps. The standard of NTDB was published in
1994 and its database was created at the same time. In NTDB geometric data was stored in MicroStation design format (DGN)
which each feature has a link to its attribute data (stored in Microsoft Access file). Also NTDB file was produced in a sheet-wise
mode and then stored in a file-based style. Besides map compilation, revision of existing maps has already been started. Key
problems of NCC are revision strategy, NTDB file-based style storage and operator challenges (NCC operators are almost preferred
to edit and revise geometry data in CAD environments). A GeoDatabase solution for national Geodata, based on NTDB map files
and operators’ revision preferences, is introduced and released herein. The proposed solution extends the traditional methods to have
a seamless spatial database which it can be revised in CAD and GIS environment, simultaneously. The proposed system is the
common data framework to create a central data repository for spatial data storage and management.
1. INTRODUCTION
In recent year population growth increases and changes in
building and constructions make some change on maps.
Determining of these changes on the old maps requires a
comprehensive strategy. In our product line for collection of
base maps in 1:25000 scales we attached element attribute.
These maps are called NTDB maps (National Topographic
Database). These data converted to a GeoDatabase that we
called NGDB (National GeoDatabase). In our strategy we use
ArcSDE and each editor connect to this database with a specific
version. After editing, changes could be extracted and new
attribute should attach to them. This strategy can reduce data
redundancy and control of data entry could apply perfectly.
2. BACKGROUND
2.1 National Topographic Database (NTDB)
NTDB refers to standard map generation and attribute data that
maintain compact and fully detailed maps. In this maps attribute
data and spatial data are linked together. There is sufficient
predefined layer for describing each feature in the map. Spatial
data have an individual geometric attribute in the map and
attributes are linked to these features via a Database
Management System (DBMS). This kind of maps produced due
to lack of desirable and applicable GIS environment in the past.
" Corresponding author
NTDB provide an excellent data source for further GIS
projects.
2.2 National GeoDatabase (NGDB)
NTDB data are not in an acceptable format for GIS projects. It
should be optimized with newest format of GIS data. First of all
a comprehensive data model introduced and a suitable schema
for entering previous data based on predefined standards were
published. This was called NGDB. In the second step all of
features from NTDB must transfer to that well-defined schema.
Because NTDB are stored in sheets, all of features in the
boundary of sheet separated between two sheets. It makes some
problem for further works or it causes difficulties for its
representation. An application was established to remove this
obstacle in these maps to made seamless NGDB.
3. CONCEPTUAL FRAMEWORK OF THE PROPOSED
REVISION STRATEGY FOR NGDB
Our strategy is divided to three main parts. In each part we
consider important details of revision trend. First of all, we
must prepare spatial and conceptual data in a desire format. In
the second step operators should extract changes and field
surveying should prepare update conceptual information. In this
part we prepare a user-friendly application to make this trend
easier for operators. The last procedure is about controlling of
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