Brief introduction of "3S" technology

"3S" technology is the general name of Global Navigation Satellite System (GNSS), Geographic Information System (GIS) and Remote Sensing (RS). So named because all three technologies contain an S in English.

1. Global Navigation Satellite System

Global Navigation Satellite System (GNSS) is a space radio positioning system, which includes one or more satellite constellations, which can be expanded to support predetermined activities as needed, and can provide users with 24-hour three-dimensional position, speed and time information anywhere on the earth's surface and in outer space. At present, the core components of GNSS are: the global positioning system of the United States, the Russian global orbiting navigation satellite system, the Galileo positioning system and the Beidou satellite positioning system of China.

Global Position System (GPS) is a new generation of space satellite navigation and positioning system approved by the US Department of Defense and jointly developed by the armed forces. Its purpose is to provide real-time, all-weather, global navigation services for land, sea and air for some military purposes such as intelligence gathering, nuclear explosion monitoring and emergency communication. It is an important part of American global strategy. Since 1980s, especially since 1990s, the combination of GPS satellite positioning and navigation technology and modern communication technology has revolutionized space positioning technology. Using GPS to measure three-dimensional coordinates at the same time, the mapping and positioning technology is extended from land and offshore to the whole ocean and outer space, from static to dynamic, from single-point positioning to local and wide-area difference, from post-processing to real-time (quasi-real-time) positioning and navigation, and its absolute and relative accuracy is extended to meters, centimeters or even millimeters, thus greatly broadening the application scope.

Global Orbital Navigation Satellite System (GLONASS), also known as GLONASS system. It was first developed in the former Soviet Union. 1993, Russia began to establish its own orbit navigation system. The main services of the system include determining the coordinates and moving speed information of land, sea and air targets. The satellite constellation of GLONASS system consists of 24 satellites, which are evenly distributed on three approximate circular orbital planes. There are 8 satellites on each orbital plane, with an orbital height of 19 100km, an operating period of 1 1 hour15min and an orbital inclination of 64.

Galileo positioning system is a satellite positioning system under construction in the European Union. It is called "European version of GPS" and is the third positioning system available for civilian use after the United States and Russia. Galileo positioning system was completed before the end of 2007 and put into use in 2008. A total of 30 satellites were launched, including 27 working satellites, 3 spare satellites and 2 ground control centers. Galileo positioning system will provide positioning and navigation services with an accuracy of 1m for road, railway, air and sea transportation and even hikers in EU member countries and China, and it is expected to start operation in 2065,438+00.

Beidou satellite positioning system (BD system) is a regional navigation and positioning system established in China. The system consists of four Beidou positioning satellites (Beidou-1) (two working satellites and two backup satellites), and the ground part is mainly composed of the ground control center and Beidou user terminals. Beidou positioning system can provide users with all-weather and 24-hour real-time positioning service, and the timing accuracy can reach several l0ns (nanoseconds). The three-dimensional positioning accuracy of Beidou navigation system is about tens of meters, and the timing accuracy is about 100ns. Beidou-1 navigation and positioning satellite was developed by China Academy of Space Technology. The launch times of the four navigation and positioning satellites are 10, 3 12000, 12, 21May 25th, 2003 and April14th, 2007, respectively. The third and fourth satellites are backup satellites. During the 2008 Beijing Olympic Games, together with the existing GPS satellite positioning system, it played a "double insurance" role in the positioning and monitoring of traffic and venue safety. The basic functions of Beidou-1 system include: positioning, communication (short message) and time service. The English of Beidou second-generation satellite positioning system is Compass, and the radio frequency band registered in ITU is L-band, which has the same function as GPS, that is, positioning and timing. Beidou system can be widely used in transportation, offshore operation, environmental monitoring and other industrial units.

At present, the global navigation satellite system GNSS used in the geological industry is the global positioning system GPS of the United States.

2. Remote sensing technology

Remote sensing technology includes aviation and space remote sensing. Remote sensing refers to a modern science and technology that uses visible light, infrared, microwave and other electromagnetic spectrum control instruments on various platforms to find out the shape, size, position and interaction mechanism between ground objects and the environment through photographic scanning, information induction, transmission and processing. With the development of remote sensing technology and the improvement of spectral resolution and spatial resolution of sensors, remote sensing technology will make major breakthroughs in national geological survey, structural interpretation and lithology identification, alteration identification, geological anomaly delineation, hydrocarbon micro-leakage detection and so on. The development of contemporary remote sensing is mainly manifested in its characteristics of multi-sensor, high resolution and multi-temporal. The application analysis of remote sensing information has changed from single remote sensing data to multi-temporal and multi-data source fusion analysis, from static analysis to dynamic monitoring, from qualitative investigation of resources and environment to computer-aided quantitative automatic mapping, from surface description of various phenomena to software analysis and quantitative exploration. In recent years, aerial remote sensing has become an important aspect of remote sensing development because of its remarkable characteristics of fast maneuverability and high resolution.

3. Geographic Information System

Geographic Information System (GIS) is a new frontier subject integrating computer, geography, surveying and mapping, remote sensing, environment, city, space, information and management, and it is a spatial analysis system for collecting, storing, managing, analyzing and describing spatial data.

With the concept of "digital earth" put forward and people's understanding of it deepened, the development from two-dimensional to multi-dimensional dynamics and networking is the main direction of the development of geographic information system, and it is also an urgent need for the theoretical development of geographic information system and many fields (resources, environment, cities, etc.). ). In terms of technology development, one development is based on Cljent/Server structure, that is, users can call data and programs on the server on their own terminals; Another development is to develop IntemetGIS or Web-GIS through the Internet, which can realize remote search of various geospatial data, including graphics and images, and can conduct various geospatial analysis. This development is to further combine geographic information system with information superhighway through modern communication technology; Another development direction is data mining, which automatically discovers knowledge from spatial database to support the automation of remote sensing interpretation and the intelligence of GIS spatial analysis.

At present, the digital mapping technology in regional geological survey is a computer science and technology based on GIS, GPS and RS technology, which integrates the digital acquisition technology of field data and information in regional geological survey with the integrated organization, management, processing and social service of digital results.