? A group of doctors from Tsinghua are playing "satellite intelligence" in the sky.

With the increase of the number of satellites represented by remote sensing satellites and the improvement of information collection ability, we can have a bird's eye view of the world and perceive the changes of the earth through the high-definition images taken by satellites. For example, the ground resolution of the Forbidden City photographed on 20 17 of Gaofen II is less than one meter. Let's overlook the panoramic view of the Forbidden City from the air and enjoy the magnificent scenery in the center of Beijing.

Gao Fen II shot the Forbidden City on 20 17, and the ground resolution was less than one meter.

Behind the increasingly clear satellite images, remote sensing satellites are generating massive data-according to the statistics of Satellite Remote Sensing Application Report (2020) of the Ministry of Natural Resources [1], there are 19 remote sensing satellites in orbit in China, and the annual data volume has reached1.6 Pb (1Pb = 60).

But in the past, China's own inter-satellite transmission was not as convenient as using mobile phones in our daily life, so it was not easy to send so much data back to China. Considering that there are few satellite ground stations in China at present, only a few minutes window can be obtained when passing over China, and only a few tens of Gb of limited data can be transmitted at a time. Therefore, the time spent by satellites in data transmission is much longer than the time spent in shooting.

Take the "Gaofen II" pictured above as an example. The satellite can store about 4Tb of data and record no less than 20 minutes of shooting information. The transmission bandwidth of "Gaofen II" is 2x450Mbps, which means it takes more than 75 minutes to send back 4Tb of data. However, every time you fly over China, you can only get a few minutes' window time, so you need several downloads and a time delay of days to finally complete this work.

With the vigorous development of commercial satellites, not only the data collection and processing of remote sensing satellites have become more and more problems, but also the whole industrial chain including communication, navigation, scientific research and technical test satellites, and even the final satellite internet and the integrated network of heaven and earth are facing such bottlenecks.

Liu Dongyu | Author

Li Tuo |

More satellite data, a broader market.

Earth space is getting busier and busier. According to the statistics of UCS satellite database, as of last September, there were 4,550 satellites in Earth orbit, among which more than 1000 satellites were newly launched in the past year, which benefited from the rapid development of commercial satellite industry, especially in the United States, where there are the most satellites, and most of them are commercial satellites.

UCS satellite database and open rocket launch data

Although China's commercial satellite companies have a good development momentum, they have not sent more commercial satellites into the sky like the United States. Policy support is the most anticipated development factor for China Commercial Satellite Company. Before the Spring Festival holiday, the state issued a "big red envelope" to the satellite industry: "China Aerospace 202 1", which set the tone for commercial aerospace. Specific measures, including supporting commercial space launch-

In the next five years, China will further improve the existing space launch site system on the basis of strengthening the unified technical system of space products ... and build commercial launch stations and commercial space launch sites to meet various commercial launch needs.

There are also more business opportunities-

In the next five years, China Aerospace will seize the opportunity of digital industrialization and industrial digitalization, face the needs of economic and social development and public diversification, intensify the transformation of aerospace achievements and technology transfer, enrich application scenarios, innovate business models, and promote the deep integration of aerospace applications and digital economic development. Expand the breadth and depth of satellite remote sensing and satellite communication applications, implement the Beidou industrialization project, and provide more advanced and economical high-quality products and convenient services for all sectors of the national economy and mass consumption. Cultivate and develop new formats of space economy such as space tourism, space biopharmaceuticals, space debris removal and space test services, and enhance the scale efficiency of the space industry.

It will take time to temporarily put aside the commercialization direction of space tourism and space garbage removal. Today's commercial satellite business is still concentrated in four major areas: communication, navigation, remote sensing and scientific experiments. For China Commercial Satellite Company, since the navigation and communication field is dominated by the "national team", remote sensing has become the fastest commercialized field.

Remote sensing satellites have been highly commercialized all over the world. According to the arrangement of SIA Data and Investment Research Institute, the global satellite remote sensing service market has reached 2.42 billion US dollars in 2020, and it is expected to reach 4.36 billion US dollars in 2025 [3]. According to another data, the remote sensing satellite market in China is expected to be 81.80 billion RMB in 2020, and the annual growth rate from 20/kloc-0 to 2020 will be 8.23%~8.34%. [4]

Global market scale of satellite remote sensing service industry. Figure SIA, Toubao Research Institute [3]

Market size of remote sensing satellite industry in China. Figure 3 Prospective Industry Research Institute [4]

The booming market will always face the problems at the beginning of the article: a large amount of data, but few effective data; Long transmission time leads to poor data timeliness, which limits the application scenarios of remote sensing satellites.

For example, a typical optical satellite shoots 10 minute in a certain flight, and the data transmission needs to fly around the earth ten times or more, and only a part of the original data can be returned each time it passes over China. Cao De, co-founder and chief operating officer of Xingce Future, introduced to Shell Hard Technology that among the raw data that took a lot of time and were downloaded by satellite energy, due to cloud cover and other reasons, the proportion of invalid data may exceed half.

There is also a remote sensing satellite, SAR satellite, called "Synthetic Aperture Radar". This is a satellite that uses microwave radar to detect, which is not affected by weather and clouds. It has the advantages of all-weather, all-weather, very sensitive to the height of surface objects (the highest accuracy can reach millimeter level), and can also analyze information such as surface vegetation and water content, so it is especially suitable for meteorological disasters, emergency, agriculture, maritime affairs and other needs, serving finance, national defense and public undertakings [5].

In the rainstorm in Henan last July, Henan Natural Resources Satellite Application Technology Center called SAR satellite data at home and abroad to analyze the flooded areas and urban roads. [6]

The commercial application of SAR satellites is also limited by data processing. The typical working mode of SAR satellite is "strip imaging", that is, with the satellite in orbit, the radar scans the ground at a relatively uniform speed and continuously collects radar reflection images, and then the final remote sensing information can be spliced after a long period of original data transmission.

How to better explore the value of satellite data and apply it to various business scenarios? An easy-to-understand solution is to compress or even filter the data on the satellite and return only the most important information.

This method must be based on calculation, just like on the mobile phone. In order to process photos, we plug several chips such as ISP and NPU into the mobile phone and a series of scene recognition and image processing algorithms. But on the satellite, how to solve the problem of minimum computing power and algorithm?

How to realize satellite intelligence?

At present, one of the main tasks of "Measuring the Future of Stars" is to provide these remote sensing satellites with energy-efficient edge computing platforms and scenario application solutions, and improve their data computing and transmission processing capabilities through on-orbit compression and on-orbit processing, thus providing services for downstream application markets such as finance, emergency response and regional security. In fact, the intelligent processing of remote sensing information is also divided into different levels, which can not only solve the problem of data transmission, but also improve the value and operational efficiency of satellite data.

The most basic work is to compress the data on the satellite, so as to reduce the size of the returned data packets and reduce the pressure on the communication bandwidth.

Optical satellite image compression (long optical satellite, the future of stellar measurement)

The first intelligence is to filter out invalid data, such as removing images blocked by clouds, or discarding photographed ocean parts when there is a clear task, such as scanning the ground. This part of the work can also save data traffic.

The more advanced intelligence is to accomplish the tasks of target identification and tracking directly on the satellite. This is also the key to make satellite data have high commercial value. Originally, it needed to complete the complete data transmission on the ground. If it is recognized on the satellite, it can directly obtain effective slice data or target information, and even adjust the working mode of the satellite constellation to further accurately collect important local information.

SAR satellite identification ship (institute of celestial instruments, future of star measurement)

SAR satellite ship monitoring and water body identification

(Xiamen University Tianyi Research Institute, Xingce Future)

Moreover, if the satellite's task includes identifying specific targets such as smuggled cargo ships, the intelligent satellite can even report a short message to the ground in real time, "something has appeared in a certain position", which is more real-time than sending back images.

It can be seen that with the improvement of intelligence, satellite data is closer to business needs, which can supplement and expand many application scenarios that traditional remote sensing processes cannot achieve.

In order to realize satellite intelligence, it is necessary to introduce low-cost and high-efficiency computing power for satellites. What kind of chips and on-board computing platforms are suitable for computing in space? Usually, the chips of satellites are special products for aerospace, which often adopt mature technology and have high stability, but they have no advantages in performance, power consumption and price. Using chips standardized by large companies has become a low-cost and computation-intensive option, but it is not necessarily suitable for working in space environment.

It is here that the future of stellar measurement opens a breakthrough. Cao De introduced Shell hard technology. CEO Cang and Cao Dezhi are brothers who graduated from nuclear electronics Laboratory in department of engineering physics, Tsinghua University. In the past, nuclear electronics Laboratory participated in the cooperation with CERN (European Nuclear Center), provided many high-performance software and hardware platforms in irradiation environment, and completed the screening and processing of hundreds of Gb of Qualcomm data per second. Therefore, the professional background of the team is to fully understand the software and hardware computing platform and its application in the irradiation environment.

From 20 16, undergraduate and graduate students in the laboratory have simultaneously carried out a space exploration project-"Sky Grid Project". Using the space exploration load carried by the commercial cubic satellite platform, the constellation networking scheme of gamma storm survey is carried out. This also inspired the entrepreneurial team to use CubeStar to carry out space experiments, deepen the understanding of space particle detection and space irradiation, and send the chip and on-board computing platform into space for on-orbit verification after sufficient ground testing, so as to help the future iterative reliability reinforcement scheme design of satellite testing, including hardware screening of heterogeneous systems, redundant backup of software systems, fault-tolerant design and verification optimization of algorithms established through neural network architecture search.

Therefore, the team has developed a variety of "Star Seal" series on-board computing platforms, which all use commercial devices (such as FPGA, GPU or ASIC chips, etc. ) to replace space-class equipment, reducing industry costs, but with high redundancy and reliability.

"Xingxi" has been iterated several times since 2020. At present, the mature product Xing Xi 02 adopts the calculation scheme of FPGA+GPU, which can achieve 20W power consumption and 20TOPs computing power. According to the launch plan, this month (February, 2022), Xingxi 02 will be launched on a satellite platform and deployed in orbit, so as to realize the on-orbit verification and subsequent long-term operation test of industrial-grade devices.

Xingxi 02 product concept map

According to reports, the future satellite measurement on-board intelligence scheme has reached cooperation with many domestic commercial satellite enterprises, such as Changguang satellite in the field of visible light remote sensing and Tianyi Research Institute in the field of SAR satellite. Through extensive cooperation in the industrial chain, satellite measurement will gain more key opportunities such as on-orbit verification and business scenario expansion in the future, and realize the process from scientific research and engineering prototype to marketization.

Technical service scientific research

Another future business of satellite survey, the "Star Survey" series of space experimental platforms, is to carry out products and services including space irradiation test, space particle detection, general data acquisition and processing through the load form of scientific research satellites.

Cao De introduced to Shell Hard Technology that the "Star Measuring" platform also originated from their technology accumulation in the field of space exploration, and its product advantages are as follows:

First, scientific load development can be realized at lower cost, and new technologies can be verified in faster time. A large-scale scientific research satellite usually carries multiple experimental loads, which constitutes a complex system. The system risks brought by many new technologies require on-orbit testing of key technologies in the early stage. Satellite measurement space experiment platform is a combination of load development capability and space irradiation test service to complete this task and help large scientific research satellites reduce risks.

Second, independently use small satellites to collect data, and quickly promote the birth of space science research results. A large-scale scientific research satellite usually needs 5~ 10 years of research and development cycle, but based on low-cost, high-reliability commercial point load products and cubic satellite carrying mode, the observation and data acquisition of scientific objectives can be completed in just one year, and new scientific research results can be published.

Third, opening up a new observation mode of space science, and realizing scientific observation modes such as array and relay through multi-satellite networking, such as observing the explosion position of celestial events facing cosmic transient sources, such as long-term relay observation facing the sun and nebulae, will open a new window for astronomical and cosmological observation from a new angle.

On the one hand, the "satellite survey" platform serves the scientific exploration of scientists and has the functions of reducing costs, accelerating speed and promoting the development of scientific research industry. On the other hand, it has also strengthened its own technical verification in future satellite measurement, making future satellite measurement always at the forefront of new technologies in the fields of space exploration, satellite data acquisition and on-board edge processing.

Cao Dezhi said that although the market space of scientific research satellite services is limited by scientific research funds, which is roughly several billion yuan/year, for the future of satellite measurement, the situation in the industry has been opened through the "satellite measurement" platform business, and the brand has been established, which has become the main source of cash flow for the company's first-phase business.

How does a doctor run a company?

We are also curious about a question: the future team members of Star Measurement mainly come from famous universities and research institutes such as Tsinghua, Stanford and Chinese Academy of Sciences, and most of them are engaged in product research and development; For the two founders and several core management team members, this is also their first job. How did they change from researchers to business managers?

According to reports, the future team of Star Measurement is small, with about full-time 10 and 30 part-time interns. However, at the beginning of the company's establishment, faced with domestic epidemic situation, R&D division of labor, production debugging and other conditions, it also opened the road of remote cooperation. Because of the team's university background, Star Future team attached great importance to the preservation of documents and the circulation of information from the beginning. "This may be a habit or culture of our company. If you can't figure it out, write it down and convey it more completely and systematically with documents. " Cao Dezhi said this.

This coincides with the idea of flying books. Therefore, after investigating a number of office collaboration platforms, I finally chose to use Feishu to carry the company's platform for document recording and conference calls. Because as one of the representatives of domestic office cooperation, Shu Fei has also introduced a meeting mode-"flying reading meeting", a meeting mode based on reading and commenting on Shu Fei documents.

Cao Dezhi said, "The most important thing for start-ups is not to be distorted. People can communicate frankly, sublimate information, quickly connect customer needs with products, and finally realize the improvement of the whole business. " In the process of using flying book documents, the team also developed some suitable working modes according to the company's development and business needs, one is the knowledge base built with documents, and the other is the customer management system built with multidimensional tables.

For a startup company, mature CRM or low-code tools are good, but they do not mean that they can solve the core problems in business processes. "First you have to figure out how to do it, and then the tools can play their due role." Behind simple forms and documents, you should clearly express what you want to do and what you want to convey, and then you can accelerate the business development of start-ups.

"Information can be transmitted from one place to another through documents and multidimensional tables. The information flow mechanism provided by Shu Fei has become a very important part of our business. The code and files carried by the flying book will eventually be taken to the sky. " Cao Dezhi summarized the role of flying books in specific work.