USING SDI AND WFS FOR QUALITY ASSURANCE
ON FIELD DATA COLLECTION
Mohammad Hosseinpour 1 , Ali Asghar Alesheikh 2 , Majid Hamrah 2
'GIS M.Sc student at KNT University of Technology Hosseinpour. - mhp@gmail.com
Associate Professor at KNT University of Technology
- Alesheikh@kntu.ac.ir
KEY WORDS: SDI, Web Feature Services, Data Quality, Field Data Collection
ABSTRACT:
Nowadays, various organizations collect new spatial data or update existing ones. If a specific information community collects
spatial data with regards to its own requirements, purposes and applications then other information communities may not be able to
use the data easily. In addition to quality issues of the collected data, the semantic heterogeneity plays a major role in spatial data
sharing. An important objective of establishing spatial data infrastructure (SDI) is to share data between diverse information
communities through exerting policies and standards. As such, SDI can provide a suitable framework to for collecting, sharing and
using data.Web Feature Services (WFS) are suitable tools for achieving this aim because they consist of information about features
definitions and their complete attributes. This leads to solve the problem of different understandings from a specific feature. In
addition to this, it is possible to formulate integrity constraints using ontology programming languages and implement the rules
during field data collection.This paper aims to investigate the way of imposing quality controls on acquired data during field data
collection. As a prototype, a mobile data acquisition system has been designed that warns users when any data inconsistency occurs
and users can remove the error from database with correcting the occurred error instantly.
1. INTRODUCTION
Nowadays, various organizations collect new spatial data or
update existing ones. If a specific information community
collects spatial data with regards to its own requirements,
purposes and applications then other information communities
may not be able to use the data easily. In addition to quality
issues of the collected data, the semantic heterogeneity plays a
major role in spatial data sharing. An important objective of
establishing spatial data infrastructure (SDI) is to share data
between diverse information communities through exerting
policies and standards. As such, SDI can provide a suitable
framework for collecting, sharing and using data.
At the other side, in the field of data acquisition, using mobile
geographic information system (Mobile GIS) has facilitated the
task of collecting or updating data and whereas these data are
mostly transferred directly to database so there is need to assess
them from the quality viewpoint and semantic accuracy to avoid
inconsistency in database. The best way for this work is to
control data during their collection in the field.
The aim of this paper is to address the way of exerting these
quality controls on data during their gathering in the field. In
order to achieve the mentioned scope, the basic concepts like
SDI, WFS and Mobile GIS are described at first and then in the
following sections these concepts and technologies are used to
impose quality controls from the early stages of data acquiring
and in the last section an implemented mobile data acquisition
system is presented as a prototype.
2. SPATIAL DATA INFRASTRUCTURE
Spatial data refers to the subset of data that is related to the
earth such as: topographic data, geographic features and height
information. Approximately 80% of used data in government
decisions are spatial or at least related to the earth [1]. For
using spatial data, they must be accessible and easily usable.
These data have a major role in spatial decisions and people can
have a better decision with using suitable spatial
data.
Many private and public organizations are acting in the field of
producing and maintaining spatial data and their products
perhaps are the same. Then for avoiding these extra works and
saving money and time, data sharing will be the crucial issue in
the field of spatial data. That means each organization that
produces a dataset, should inform users and other organizations
that may need that data.
1.1 SDI Definition
There are some definitions for spatial data infrastructures but
the thing that is common between them is creating the area that
all could collaborate with each other to reach their purpose in all
organizational and political levels. Regarding the different
existing branches, there are different definitions for SDI but in
this paper Groot and McLaughlin’s definition of Spatial Data
Infrastructure has been adopted [2]:
“Spatial Data Infrastructure encompasses the networked spatial
databases and data handling facilities, the complex of
institutional, organizational, technological, human, and
economic resources which interact with one another and
underpin the design, implementation, and maintenance of
mechanisms facilitating the sharing, access to, and responsible
use of spatial data at an affordable cost for a specific application
domain or enterprise.”
2.2 Core components of SDI
With reference to existing definitions for SDI, the main
components of SDI can be recognized. As shown in Figure 1