After the deployment of Beidou navigation system, why didn't we launch a high-precision map similar to Google maps?

Many people think that the map is made by Beidou 、GPS Wait for the satellite to send it to us , But it's not , Location data is only a small part of the electronic map , But it is definitely a very important part , Because after positioning , The map can realize the function of navigation , All vector data 、 The base map layer will live up and become more meaningful .

After the Beidou navigation system is deployed, I believe everyone is looking forward to a Chinese version of Google maps （ Google Earth ）, Be able to browse high-definition maps of the world , Including satellite image data 、 Topographic and geomorphic data 、 3D spatial data . Why hasn't there been any movement so far ？

So today we're going to popularize science Why did the Beidou navigation system not launch a high-precision map after deployment ？

What is Beidou navigation system ？

First, let's learn about the concept of Beidou navigation system .

2020 year 6 month 24 The Japanese Beidou navigation system has completed networking , All weather navigation system . It mainly provides global positioning services for other equipment （ Time difference of electromagnetic wave signal between the equipment and Beidou satellite + The Beidou satellite ephemeris shows the position of the Beidou satellite in the sky , Then the spatial coordinates of the equipment are determined by the algorithm of triangulation ）.

Each networked navigation satellite on the Beidou system will broadcast time information to the ground at all times 、 Accurate track information （ Ephemeris ） And the health parameters and rough orbit information of other navigation satellites in the navigation constellation system .

And for us , We actually use the Beidou navigation system everyday , For example, we turn on the mobile phone , If you are using Baidu map or Gaode map , All through a variety of satellite positioning , Here is the positioning in Beidou navigation system .

Make it clear that Beidou is a navigation system , Not a map . Now it has covered the main areas of the world , There are almost no blind spots , In addition, the positioning accuracy is greatly improved , The application fields and scenarios are more extensive , It can completely replace the United States GPS The ability of .

How high definition maps are created and located ？

High definition electronic map is based on GIS, It is a combination of geography and cartography , Mainly used to input 、 Storage 、 Inquire about 、 A computer system for analyzing and displaying map data .

Electronic maps describe space through different layers , Then, the overlay display of layers is used to realize the expression . Different application goals , The superimposed layers are also different , such as ： Open on map 、 The process of shutting down road traffic , It turns off a layer .

Satellite imagery 、 Aerial image 、 Telemetry electronic map 、 The externally collected street view map is used as map data , They are through tile models （ Also called grid model ） To simulate an entity . When we zoom the map , The system will provide us with tile maps of different resolutions from the server according to the zoom level to piece together a complete map , This is why when the Internet speed is very slow , We can see the process of switching and splicing pictures with different resolutions .

The restaurant 、 The store 、 Gas stations and other points also have a name POI Data layer of ,POI Layers 、 Traffic layer 、 Three dimensional drawings are expressed by vector models , Is to put the natural land 、 The object passes through the point , Line , Face to face .

Through Beidou 、GPS The collected positioning point information is also expressed by vector model . Satellite positioning is actually a typical triangulation , The satellite receiver measures the transmission time of the signal from the satellite to the receiver , Calculate the distance to each satellite （ The speed of light x Time ）, And then determine the current position according to the distance and position of other satellites , And the change of position , You can display information such as direction and speed .

Navigation satellites do not transmit image information , It will only broadcast its positioning signal like a broadcasting station , The navigation receiving equipment only passively receives the signals broadcast by the navigation satellite , Then the signal is processed by the internal chip and the accurate position is calculated , Displayed on the electronic map .

As for the reasons why no similar Google maps has been launched, there are mainly the following aspects ：

1、 Cost perspective

The data source of satellite images is not single , For example, Google maps is a combination of satellite images and aerial data . Some of the satellite images come from the United States DigitalGlobe The company's QuikBird Commercial satellites 、GeoEye Earth observation satellites and EarthSat The company's LANDSAT Landsat （LANDSAT-7、LANDSAT-8） etc. ; Some aerial images are from Britain BlueSky company 、 In the United States Sanborn Company, etc .

The satellite remote sensing images used for domestic satellite maps are provided by China four dimensional surveying and Mapping Technology Co., Ltd . All the shadow image data of China thinking comes from commercial satellite data providers DigitalGlobe company .

The cost of map data is huge , It usually includes the cost of data collection 、 Technical treatment 、 Data storage costs 、 Operation management and maintenance cost, etc , The annual cost of expenditure is about hundreds of millions of dollars , Of course, the income is also quite large , Take Google Earth for example, the annual economic output value （ Mainly the advertising part ） About billions of dollars .

In this regard, Google maps has been at the forefront , If we invest a lot of money in the early stage to build a second “ Google Maps ” From the perspective of input and output, it may not be a stable investment .

2、 Map ecological construction takes time

Let's discuss the ecological construction of Beidou with the case of Google maps . Google uses imaging satellites, street view photography and various Google shopping malls App、 Even the Android platform collects data , And then integrate through Google . And then on this platform, we can communicate with GPS When combined, we have high-definition satellite images 、 Navigation function , Such as cloud computing 、AI、5G Combine to have automatic driving . This is also a direction of Beidou's efforts , At present, Gaode is involved in Beidou navigation in China 、 Baidu 、 tencent , But in terms of data collection, it is still not as strong as Google , Not to mention renting satellites to shoot the earth .

Beidou 2020 year 6 month 24 The networking was completed on the th day , and GPS Good morning! 1993 year 6 month 26 The networking has already been completed , Difference between 27 year , Don't expect your child to grow up one night .

3、 Policy reasons

Google image map should be the most comprehensive coverage at present 、 The map with the highest local resolution , There is a similar sky map in China , But compared with Google, it can not reach the highest resolution of Google 、 The update will be delayed for a long time , At present, it basically covers the whole country .

The main reason for the difference is that the domestic high-definition image map belongs to the scope of confidentiality management , It is not allowed to provide high-resolution images on the Internet . Google doesn't have a confidentiality problem , It can buy commercial satellite images , Up to 0.5 Meter resolution （0.5x0.5 The meter size will become a point on the map ） And can be published on the Internet , So the policies of different regions in the world are different .

4、 Technical considerations

At present, the high-tech fields dominated by China and the United States are competing for games , Especially in 5G、 Aerospace science and technology 、 semiconductor 、 Software technology and other fields , The United States to “ The so-called national security ” To contact a group of younger brothers , In these sophisticated fields, we have gone beyond the continuous suppression and technical blockade on us , Let's get some key technologies “ thetime ”, It's a little unrealistic to want to make up all the shortcomings at once

Of course, there are other reasons like GJ Security 、 Strategic issues such as the return of the Gulf

Last

as far as I am concerned , China to 2021 The end of the year will have 200 Based on GNSS Navigation and positioning 、 High precision earth resources satellite , Include GAOFEN,YAOGAN（ High score series satellites 、 Remote sensing series satellites ）.

it is anticipated that , In the near future, China will really have a system similar to Google maps and Google Earth , And all over the world , Accuracy is much higher than Google data （ The accuracy of Google image data is generally 5 rice , In North America 3 rice ）.

Before the real domestic Google Earth came out , You want to browse 、 Download global HD （ Google ） Satellite imagery , You can use it. 【 Figure New Earth computer version 】 perhaps 【 Field spirit app】 Import google satellite image data for browsing , This software is known as “ Domestic high configuration version of Google Earth ” Software , It is one of the few software in China that can browse global high-definition satellite images .

Now for us , We still need to fill the loopholes in a down-to-earth manner , When all the loopholes are filled, the real transcendence will be realized .