1235
OBJECT IDENTIFICATION BASED ON MULTI-REMOTE SENSING IMAGES IN THE
LACKING AREA OF 1:50 000 TOPOGRAPHIC MAP OF TIBETAN PLATEAU
Zhigang Hong a ' *
a Chinese Academy of Surveying and Mapping, Beijing 100039, China - hongzg@casm.ac.cn
KEY WORDS: SPOT Image, 1:50000 Topographic Map Schema, Ground Objects Interpretation
ABSTRACT:
The lacking of 1:50000 topographic maps in western China is inconvenient to the national economic development. The rapid
development of space technology, computer technology and information technology provides technological support for the remote
sensing application. In addition, the enhancement of ability of obtaining hyper-resolution data provides data for feature extraction of
ground objects. This paper employs SPOT5 RS image, based on the schema standard of 1:50000 topographic maps, to interpret the
Qixiangcuo region in the Tibetan Plateau. The results indicate that the SPOT5 can meet the needs for 1:50000 topographic mapping.
In order to further improve the interpretation multi-temporal and multi-resolution image are suggested to be used to interpret ground
objects in 1:50000 topographic maps.
1. INTRODUCTION
1:50000 topographic maps are indispensable fundamental
geographical information which can be used in national
economic construction, geologiccal investigation and surveys,
environment protection, water and biological resources
exploration and national security. In western China, around
200* 10 4 Km 2 area in Sorth Xinjiang desert region, Tibetan
Plateau and the Traverse Mountains region does not have
1:50000 topographic maps due to the weather condition,
environment limitation, traffic inconvenience as well as the
restrictions of the mapping technology and equipment in the
past. The lacking of these maps not only restricts region
economic and social development, the traffic and water
conservancy construction, natural resources and mineral
surveys, but also seriously impacts the economic development
and national security of the western region of China. Along
with the implementation of the western exploitation and the
national sustainable development strategy, the development of
the western infrastructure, resources survey and exploitation,
ecological construction, environmental protection, the
development of modem digital military directive system,
antiterrorism and maintenance of the border security, the
western scientific and cultural progress etc, all urgently need
the 1:50000 topographic maps. Due to the need of large data
sets for mapping 1:50000 topographic maps, high data
acquisition technology is required. Especially for the routhless
area, the spot reconnaissance is more difficult. In recent years,
the rapid development and the popularization of remote sensing
(RS) technology makes it possible to solve this problem. Using
RS images as the data source to update the topographic map is
increasingly used in land resources survey and monitoring
(Jiang, 2001;Wang et al., 2002; Feng et al., 2004; Jiang et al.,
2004).
In recent 20 years, the RS application has been highly improved
by means of the development of space technology, computer
technology and information technology (Liu et al., 1997; Lin et
al., 2003; Zeng, 2004). Different RS images have different
characteristics in feature extraction. SPOT-5 satellite was
launched on May 4 th , 2002 by the French Ariane 4 launch
vehicles. It is the last one of French Space Agency SPOTS
satellite series which is obviously different from the former 4
satellites. There are two HRG and a HRS instruments on it and
it mainly provides 2.5m panchromatic image and 10m
multispectral data. The characteristics of each satellite channel
are shown in Table 1 and Figure 1. Currently, SPOT images are
the main RS images used by the National Ministry of Land and
Resources on large-scale national resource construction, the
land use investigation, the digital territory project, the updating
of soil resource and the land-use information system (Li, 2000;
Deng et al., 2005).
Sensor Band
Ground
Resolution
Spectral range
Panchromatic
2.5m
0.48-0.71 jum
B1: Green
10m
0.50-0.59 jum
B2:Red
10m
0.61-0.68 jum
SPOT5 B3:Near Infrared
(NIR)
10m
0.78-0.89 jum
B4: Short
wavelength
infrared (SWIR)
20m
1.58-1.75 jum
Table 1. SPOT5 data spectral bands and resolution
2. THE OVERVIEW OF STUDY AREA
The central part of the lacking area of 1:50000 topographic
maps is Tibetan Plateau which is the highest one in the three-
class ladder. It is bordered by the Pamirs in the west, Traverse-
Mountains in the east, the Himalayas in the south, the Kunlun
Mountain, Aerjin Mountain, and Qilian Mountain in the north.
It covers the area from N 42°45' to N67°10' in latitude and from
E81°00' to E106°00' in longitude. It is 2500km in length of EW
and 1200km in width of SN. The area is 23 0 X 10 4 km 2 . In
addition, the terrain of Tibetan Plateau is high because the
average altitude is higher than 4500m and it is sloped from
northwest to southeast.
* Corresponding author. Zhigang Hong, hongzg@casm.ac.cn.