The method of using remote sensing sensors carried on satellites to obtain information on the Earth’s surface through satellite imagery.Due to the high altitude of satellites,the data resolution is generally low,usually ranging from 1 meter to tens of meters.Satellite images have the advantages of wide coverage and long data acquisition cycles,making them suitable for large-scale data acquisition.
The characteristics of satellite imagery:
1.Global coverage:able to cover various regions around the world and provide imaging data on a global scale.
2.High resolution:With the advancement of technology,the resolution of satellite images has reached a very high level,which can clearly display surface features.
3.Real time:Some satellites can provide real-time image data and monitor natural disasters,environmental changes,and other situations in real time.
4.Multiple Wavebands:It can provide image data from multiple wavebands,including visible light,infrared,radar,etc.,to meet the needs of different applications.
The functions of satellite imagery:
1.Map making:It can be used to create maps and provide basic data for geographic information systems.
2.Environmental monitoring:It can be used to monitor natural resources,environmental changes,climate conditions,etc.,which helps with environmental protection and resource management.
3.Geological survey:It can assist in conducting geological surveys to discover potential mineral resources and geological hazards.
4.Agricultural and forestry monitoring:It can be used to monitor the growth of crops,soil moisture and other information,and plays an important role in agricultural production and forestry management.
Advantages and limitations:
Advantages: Providing large-scale, continuous, and objective surface information; Can cover difficult to reach areas; Multiple sensor combination applications provide rich data sources.
Limitations: Influenced by factors such as clouds, weather, and time (mainly for optical images); Large data volume and complex processing; The cost of high-resolution imaging is relatively high.
Due to the characteristics of global coverage,high resolution,real-time performance,and multiple bands,satellite imagery has a wide range of applications in military intelligence,urban planning,disaster monitoring and prevention,environmental protection,agriculture and forestry monitoring,and other fields.