In: Wagner W., Székely, B. (eds.): ISPRS ТС VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
418 
to insert the sample images and corresponding metedata in the 
database, auto-check the physical integrity and logical integrity 
of the import data, ensure the accuracy and completeness of the 
import data. 
Querying subsystem not only supports the single term query but 
also supports the query based on group of multi condition. 
Post-processing subsystem offers friendly user interface, which 
helps the users make rapid and exact synthetic analysis. 
2.2 The organization of the data and the design of the 
database table 
The main data of the system is property data, including the land 
categories information, the metadata information of the remote 
sensing image and the information of manual interpretation. 
The metadata of the remote sensing images include the category 
of the sensor, the time of imaging, the season of imaging, 
resolution, the geographic location, and so on. The manual 
interpretation information is the land category and the terrain of 
remote sensing sample image. Besides, there are other data in 
the database, such as the store location, the category code of 
every land category and the description information of the land 
category. 
Excellent design of the database table could not only simplify 
the data flow, improve query efficiency, but also benefit the 
development and maintenance of the system. According to the 
requirements and functions of the system, three database tables 
constructed: the province and region table> land category table 
and sample image table(see Tablel, Table2, and Table3). 
Field Name 
ID 
Data Type 
Province 
Al 
Char 
Region 
Al 
Char 
Table 1. Province and region database table 
Field Name 
ID 
Data Type 
Land Category 
B1 
Char 
Category Code 
B2 
Integer 
Category Description 
B3 
Char 
Table 2. Land category database table 
Field Name 
ID 
Data Type 
Ordinal Number 
Cl 
Integer 
Province 
C2 
Char 
Land Category 
C3 
Char 
Terrain 
C4 
Char 
Sensor 
C5 
Char 
Imaging Year 
C6 
Integer 
Imagine Season 
Cl 
Char 
Resolution 
C8 
Float 
Store Location 
C9 
Char 
Table 3. Sample image database table 
The province and region database table records the relationships 
between all the Chinese provinces and the regions which they 
belong to, such as North China, Northeast China, East China, 
Middle China, South China, Southwest China, Northwest China. 
The land category database table records the names, codes, 
description information of the 8 top-level land categories, 38 
second-level land categories. 
The sample image database table is the main table of the 
database, all the information of the land cover remote sensing 
sample images stored in this table. The records number in the 
province and region table and land category table are fixed, but 
the records in the sample remote sensing image table could 
extend or decrease by adding or deleting the sample remote 
sensing images. 
The design of the database table separates the main table and 
the minor tables, reduces the redundancy of the data. This 
strategy will benefit database’s query and update processing 
significantly. 
2.3 Development 
.NET is Microsoft’s new generation development platform, 
which offers the foundation to quickly construct the mutual- 
communication application system. .NET Framework, as the 
soul and foundation of the .NET, provides many new features, 
such as mutual-operation ability, common language runtime, 
independent language, simple deployment, security, and so on. 
These features made .Net development widely used now. Any 
software system based on the powerful .NET Framework can be 
called .NET application program. 
ASP.NET is a web application framework based on the .NET 
platform, it can be used to establish dynamic web page and 
offer web application service (John Sharp, 2006; G. Andrew 
Duthie, 2002) 
To satisfy the need of running under the web environment, the 
system adopts the web service technology. The World Wide 
Web Consortium identifies the web service as the software 
system which offers the mutual operation among different 
machines by the Internet. The system adopts customer/server 
model to offer the web service, database stores in the server, 
which can be long-distance browsed and queried by the 
customers. 
The land cover remote sensing imagery retrieval system was 
constructed based on the ASP.NET and web service technology, 
adopting the C# language as the development language under 
Visual Studio .NET 2005 development platform. 
2.4 ADO.NET and XML 
ADO.NET is a set of computer software components that 
programmers can use to access data and data services. It is a 
part of the base class library that is included with 
the Microsoft .NET Framework. ADO.NET supports the 
relational database system and the non-relational database 
system at the same time. Normally, it is considered that the 
ADO.NET is the upgrade from ADO, but actually the 
ADO.NET is quite different from ADO. ADO.NET can be 
considered as a completely new production for mutual data 
access. 
ADO.NET includes two main parts: Data Provider and DataSets. 
The former can be separated into five parts: Connection, 
Command, Parameter, DataAdapter and DataReader. This 
system adopts ADO.NET technology as mutual-access engine 
for the database of remote sensing sample images. ADO.NET 
provides stable foundation for realization of the system. 
To reduce the pressure of the server, decrease the unnecessary 
visit to the server, the system caches search result quickly in the 
customer with the XML technology (Dan Wahlin, 2002). The 
following is the storing sentences: 
DataSet dsQuery = db.GetDataset(arraylist, strDbPath); 
if (dsQuery == null) 
return; 
dsQuery. WriteXml(strTempXmlFile); 
When to load the search results, there is no need to access the 
server again, with the following sentence to get the search 
results: 
dsQuery. ReadXml(strTempXmlFile);