What is IGS Satellite What does IGS mean in surveying and mapping

GPS is the abbreviation of Global Positioning System in English, and its Chinese abbreviation is "Ball System". GPS is a new generation of space satellite navigation and positioning system jointly developed by the US Army, Navy and Air Force in the 70s of the 20th century. Its main purpose is to provide real-time, all-weather, and global navigation services for the land, sea, and air fields, and is used for some military purposes, such as intelligence gathering, nuclear explosion monitoring, and emergency communications.

After more than 20 years of research and experiments, costing 30 billion US dollars, by March 1994, 24 GPS satellite constellations with a global coverage rate of up to 98% had been deployed. In the field of machinery, GPS has another meaning: Geometrical Product Specifications - GPS for short.

Japan's "Intelligence Gathering Satellite" (IGS) system is mainly composed of two parts: a space system and a land system, with a total cost of $2.5 billion, including the cost of manufacturing and launching four satellites, data processing, and ground station construction.

Space systems, the first generation of IGS systems include optical imaging satellites IGS-1A and -2A, and radar imaging satellites IGS-1B and -2B. The satellite operates in an orbit of 400 600 km with a resolution of 1 m for IGS-1A, -2A and 1 m for IGS-1B, -2B. After the deployment of the second-generation IGS system, Japan's satellite reconnaissance system will be able to conduct reconnaissance of any target on the earth twice a day, and transmit the relevant data to the ground intelligence processing center in real time through the "Data Relay and Tracking Satellite" (DRTS, launched into orbit on 10 September 2002) in synchronous orbit, enabling Japan to have a near-real-time space reconnaissance and surveillance capability.

It is reported that the IGS satellites will also be used in conjunction with the ALOS satellites. The terrestrial system, i.e., the terrestrial satellite signal reception and processing system. It is mainly composed of 1 satellite intelligence data processing center and 3 ground stations.

The Satellite Intelligence Center in Shinjuku, Tokyo, is the central organization of the IGS ground system, responsible for the collection and processing of satellite intelligence, as well as the analysis and interpretation of images. The center was established in March 2003 and currently has a staff of 320 people, including about 100 image interpretation analysts (up to 150 trained in the United States); The three ground stations are the Kitaura Satellite Information Center in Kitaura, Ibaraki, the Tomakomaki Satellite Information Center in Tomakomai in Hokkaido, and the Akune Satellite Information Center in Akune, Kagoshima, Prefecture. At the same time, Japan has built a Perth satellite control post in the Perth area of western Australia.

IGS (Interactive Graphics System) is an operation method that uses a computer instead of an analytic mapper, a digital image instead of an analog photograph, and a digital cursor instead of an optical cursor. Carry out ground object data collection and generation on stereo or orthophoto images to generate digital measurement pieces (*.xyz), which is superimposed on the stereoscopic image in the matching preprocessing, and then participates in the image matching, sets up the operating environment, and can carry out ground object measurement and map elements.

It stands for International GPS Service (IGS), an international collaborative organization established in 1993 by the International Association of Geodesy (IAG) to support geodesy and geodynamics research.

1) First have a thorough understanding of the precision ephemeris, its accuracy, its classification, generally we use the fast precision ephemeris, and the final precision ephemeris, the former is released 17 hours apart, the accuracy is 5cm, and the observation interval is 15 minutes. The rest seems to be going to take a few days.

2) The same is true for precision clock differences.

3) Use VB programming to extract the precision ephemeris and precision clock deviation of each satellite separately and save them separately.

4) The following is quite important, the main building is to find a suitable method for interpolating the precision ephemeris, here to use the content of numerical analysis--- Lagrange interpolation, and linear interpolation.

1) Precise ephemeris is interpolated with Lagrange interpolation, so how to interpolate?

1) We need to know how many orders need to be interpolated with Lagrange, for example, 16 orders, then we need 17 interpolation nodes, interpolation with time to do the x value, the coordinates of the satellite as the y value, if the landlord requires a precise ephemeris within a day, of course, it needs a three-day precision ephemeris, the day before, the day, the day after, because to find the beginning and end of the day when the satellite coordinates are used.

2) Determine the interpolation order, select the interpolation node, you can interpolate, the specific method is to take a good look at the Lagrangian interpolation. The interpolation time is the core and difficult point, and after figuring it out, use MATLAB, and there is a function of Lagrangian interpolation on the Internet. Programming calculations are quite troublesome, mainly the selection of time and the number of cycles.

By the way, the number of interpolated precision ephemeris depends on your GPS observation interval, and the known precision ephemeris should not be interpolated, and there is a way to judge whether it is known, hehe, it's a headache.

3) The precision clock difference can be taken with an observation interval of 30 seconds, and linear interpolation is used, and the method is the same as above.

IGS is a file format prescribed by the U.S. Information Management Commission, which is mainly used for file conversion of different 3D software systems.

The file format can be opened by 3D modeling software such as UG, SOLIDWORK, CATIA, PRO-E, etc., but cannot be modified.

The files in this format are generated according to the IGES standard. IGES is the de facto international standard data exchange format widely used by all countries, and China will be the national recommended standard from September 1993. The standard is built on top of Boeing's CAD CAM integrated information network, General Electric's central database, and various other data exchange formats.

.IGS is a common format for CAD files IGS is a file generated according to the IGES standard, which is mainly used for file conversion of different 3D software systems.

IGS is a file generated according to the IGES standard, which is mainly used for file conversion of different 3D software systems.

It is a 3D image file, which should be opened with professional design software such as Pro-E or UG. Since you have asked and said that you have not installed these software, then you can ask your colleague to convert to pdf file, but you can only see it after the conversion, but you can only make changes. It can also be converted to a CAD 2D file, but you need to install Auto CAD.

IGS is mainly used for file conversion between different 3D software.

IGS is a three-dimensional digital model. There are many kinds of 3D software that can be opened, but cannot be modified.

The software that can be opened is UG, SolidWork, Catia, Pro-E, etc.

Dassault Systèmes has launched 3DVIA Mobile HD, a browser that allows you to interactively display and manipulate 3D models on your iPad. It's small, it's convenient, and it can be seen in almost all 3D formats.

CAD to open IGS requires a plug-in for AutoCAD Mechanical, and the IGES format introduced in 1979 has become the standard for transferring 3D models between CAD programs. However, in recent years, IGS format files have been replaced by newer STP format files.

There is nothing special about the front of a large area of Dongdong, from * 2012 4 28 0 0

At the beginning of this line, this is the time data, 0 hours, 0 minutes and 0 seconds, and downwards, the data meaning of each row is: satellite number, satellite x, y, z coordinates (m), satellite clock (s), x, y, z coordinates and clock accuracy factor.

The xyz coordinate is in km kilometers, the accuracy of the coordinate data is the base, and the clock error is the base;

For example, the 8 7 6 175 in the first row is to the eighth power, the seventh power, the sixth power...

You can refer to the Wuhan University edition of "GPS Measurement and Data Processing (Second Edition)", the precision ephemeris file format in SP3 format that will be discussed later...

It is recommended to go to the IGS official website to see the specific instructions, it is difficult to explain clearly in just a few words.