Remote sensing technology has become an important technique of active fault research because of its macro

intuitive and non-contact advantages. With the rapid development of remote sensing technology

the increasement of satellite sensors and the improvement of spatial resolution

a various data of satellite sensors at home and abroad have been widely used in active fault research. Foreign satellite data mainly include ALOS

IKONOS

SPOT

QuickBird

Worldview and so on

among which the spatial resolution of QuickBird is 0.6 m

Worldview up to 0.31 m. Domestic satellite data include GF-1

GF-2 and ZY3

where the spatial resolution of GF-1 multispectral band and panchromatic band is 8 m and 2 m respectively; the spatial resolution of ZY3 multispectral band and panchromatic band is 5.8 m and 2.1 m respectively; the spatial resolution of GF-2 multispectral band and panchromatic band is 4 m and 1 m respectively.In recent decades

the rapid development of urbanization and human activities have seriously destroyed natural landforms. Especially in the eastern part of China

natural landforms have been seriously damaged due to the construction of roads

railways

factories and houses

so that tectonic geomorphology no longer existed

which made a great difficulty for remote sensing interpretation of active tectonics. US Keyhole(KH) satellites began to run in the 1960s

taking a large number of images in China. KH images are characterized by early imaging time

high resolution and better original terrain information

so they can be effective to obtain the characteristics of tectonic geomorphology and determine the geometric distribution and fault behavior. Those are significant for active fault research.In this paper

the basic information and data processing flow of KH satellite is introduced firstly. KH satellite mainly include KH1-12 and other 12 models. KH1-6 is the recoverable reconnaissance satellite of photographic film. The data source of KH1-6 is basically open

which is the main application of the promotion model. The best resolution of KH4A

KH4B and KH6 is 2.7 m

1.8 m and 0.3 m respectively. Secondly

the application of KH images in active fault is discussed: 1) For the tectonic landform of active fault

with the advantages of early imaging time and high resolution

KH images can obtain the tectonic micro- landform features of active fault such as linear structure

fault scarp

fault cliff

fault groove and channels offset

which can not be identified by current satellite images. They are helpful to complete the precision mapping and quantitative analysis of active fault; 2) For the surface rupture zone of a historical earthquake

the KH images photographed at the nearest time after the earthquake is useful to map the surface rupture of the earthquake and measure the coseismic displacement. KH images visualize the post-earthquake rupture information to reveal the relationship between the rupture and the active fault

which guides us to understand the seismogenic structure

seismogenic mechanism and the process of diastrophism. Finally

this paper take the Jiangsu section of the Tan-Lu Fault Zone(TLFZ) as an example. The Suqian city and surrounding area were selected as the test area

where the remote sensing interpretation of the active fault based on KH-4B satellite image was carried out. The results show that

Malingshan-Chonggangshan Fault(F5) and Xinyi-Xindian Fault (F2) intermittently exposed to the surface. The tectonic micro-landforms of the two faults are very developed. In the Huangchaoguan

Shanxiawu and the south of Xiaodian

F5 exposed to the surface

which formed fault cliff

fault triangular surface

fault scarp and other structural landform. In the west of Huangchaoguan

F2 intermittent exposed to the surface

which formed fault scarp

fault deflection

fault groove and other tectonic micro-landforms. There are no obvious dislocations in the gully of the two faults. The two faults are mainly dip-slip movement with high angle thrust motion.KH satellites have obtained a large number of instantaneous image data from the last century

and recorded the process and evolution of the Earth's surface for a period of time. These images have important application values in the field of active fault research. In order to study and understand the geological structure

tectonic landforms and the latest historical changes

the KH images provide more accurate basic data. How applying KH images to active fault mapping work and seismic hazard assessment is an important development direction in active tectonics research in the future. What is more

It is hoped that

except in the earthquake industry

KH satellite data will be widely used in the fields of forestry

fishery

surveying and mapping

engineering

electric power

and other industries.