Rapidly rising SAR satellite market (Part 1) Follow logistics.Small SAR satellite from Kitakyushu and QPS Research Institute

QPS Laboratory has realized a 100-kilogram class, 1-meter resolution X-band small synthetic aperture radar (SAR) satellite equipped with a lightweight, large parabolic antenna with a diameter of 3.6 meters. The first QPS-SAR series is scheduled to be launched by the Indian PSLV rocket after October 2019. We asked Mr. Shunsuke Onishi, President and CEO, and Mr. Toshimitsu Ichiki, Director and Chief Operating Officer (COO), about the technology that realized the small SAR satellite.

－－The first machine will be launched soon. What kind of technology is included to realize a small SAR satellite?

Onishi: Unit 1 will be completed in March 2019 and will be launched by the Indian PSLV rocket after October. The satellite was also exported to India in early September. There are many technologies that will lead to the realization of a small SAR satellite, but I think the major feature of our satellite is the large parabolic antenna with a diameter of 3.6 meters. As a result of repeated improvements, the weight has been further reduced from the initial 15 kg to 10 kg, and the mirror surface accuracy for realizing high-quality radar observation has also been improved. In addition, Unit 2 is under development, and FM production is about to begin. Unit 2 also incorporates many improvements and new attempts learned from Unit 1, and we expect that performance and image quality will be further improved compared to Unit 1.

Ichiki: Weight reduction of the antenna is an essential goal for small satellites, and the metal mesh used in ETS-VIII (KIKU No. 8) is used for weight reduction. We have developed a new mechanism of patented technology that has both flexibility and rigidity, which can be stored compactly at the time of launch and keeps the shape of a parabola with a diameter of 3.6 meters.

Onishi: To reduce the size of the SAR, there is a method of downsizing the phased array antenna, which is common even for large satellites, but it requires a large amount of power. The Finnish SAR satellite company ICEYE has realized this method. The basic is the phased array method, and the waveguide method called the third method is realized without electrically controlling the element. On the other hand, there is a method of downsizing by realizing a large and light parabolic antenna like our company. However, we need a way to unfold what is folded 3-4 meters into a clean bowl. Overwhelmingly good image quality depends on the accuracy of the antenna (mirror surface accuracy), and it is a difficult technique that does not allow deviation in millimeters. The fact that we were able to achieve that is the miso.

--How long does it take from launch to antenna deployment? Also, is there a place where you have decided to "take a picture here" in the first image (first light)?

Onishi: Antenna deployment is 1-2 days after launch. It's not an automatic expansion, it's a method of opening by typing a command, so I send the command quietly (laugh).

Ichiki: It's a big milestone to develop well. I've tested it many times and I'm confident that it's okay, but I don't know what will happen in space.

Onishi: There is a place in the company that First Light has decided to be "here". If possible, I would like to take a picture of the Kyushu area, and I like the place where customers can easily judge the quality of the image and the mountains, sea, and cities can be seen well.

--It is said that SAR satellites have a large amount of data, but how do you control operations after launch?

Onishi: In operation, we will first use the ground station in the Kyushu area. When the amount of data downlink increases in the future, we will use the world's ground stations that can be shared.

Ichiki: Arranging data downlinks is really difficult. When it comes to building a constellation, the amount of data and the amount of money will be enormous even with the trial calculation alone, and the downlink is also required to be real-time. I think that all the people of small SAR satellites are one of the issues that bothers their heads. However, Unit 1 is not yet about to drop data all over the world, so we will handle it in the Kyushu area. As the amount of data increases when Unit 2 goes up, I think that we will use the world's ground station sharing service in earnest.

－－Is it the goal to realize satellite constellation by 2024 that it is possible to deploy antennas with high accuracy?

Ichiki: The goal is to raise funds after the launch of Unit 1 and realize a constellation of 36 satellites in 2024. The level of Unit 1 to Unit 2 has also been upgraded, but we plan to upgrade it once or twice after that. We are planning to load a propulsion system at Unit 3 or 4.

--What kind of service are you aiming for when the satellite constellation is completed?

Ichiki: Even if the same SAR satellite is used, the goals of each company are different, and there is a part that differentiates the orbits in which the satellites are launched. The QPS Laboratory aims to make fixed-point observations almost every 10 minutes in the world. I want to see the flow of people and things by looking at it about every 10 minutes. A car can be detected if the resolution is 1 meter. If you know the movement of cars and things about every 10 minutes, you can see the export of cars and containers at the port, how much they have been loaded, and so on. You can get data such as the number of customers from the export volume, factory production volume, and the number of cars parked in suburban stores. Also, I would like to know the changes in buildings and ground due to the interference SAR (*) technology. In Japan, especially the infrastructure is aging, so we would like to detect changes in the ground as soon as possible and provide data on breakdowns and damage.

* A technique for capturing changes in the ground using information on slight distance differences by conducting SAR observations at the same location on the surface of the earth more than once and interfering with them to take a difference. While the accuracy that can be achieved by one observation is about several meters, it is possible to measure in the centimeter class in the interference SAR, and in the millimeter class by checking the difference by repeating the observation frequency.

--Compared to optical satellites, SAR images are said to be difficult to understand and use. What are your plans for developing users using satellite data?

Ichiki: At this point, the QPS Research Institute has decided not to go through image analysis. We are satellite development professionals, but not image analysis professionals, and we may end up chasing two rabbits. Therefore, instead of providing analysis solutions directly, we are going to get partners and provide data. You are turning to places where there is potential one by one.

There was talk about whether it could be used to improve the efficiency of logistics, for example, when the movement of things was understood every 10 minutes. There is a request from a logistics-related company, "I want to track the trucks on which our products are mounted, anywhere in Japan." I thought it would be possible to use a mobile phone without using satellites, but that doesn't seem to be the case. We are listening to the issues and needs of customers in various industries, such as improving the efficiency of our distribution network, and making various proposals.

It is difficult for SAR satellites to cover the entire world due to power restrictions, but overseas image provision platforms etc. will suck up information from news and SNS and provide linked images when "accident occurrence" etc. are found. It seems that you are doing it. We are also thinking of contributing to the promotion of usage by providing images to such an image platform with real-time characteristics. We also receive requests to "enter" the platform, so we also used the platform in trials, including studying and determining which platform is likely to expand in the future, and gathered in-house on a daily basis. We are checking how it is used on the platform, good points, and problems.

--What is the background to the development of the difficult technology of SAR satellites required in the world?

Ichiki: The presence of Professor Tetsuo Yasaka, the founder of the QPS Research Institute and an emeritus professor at Kyushu University, is significant. I'm already a grandpa in his late 70s, but when Onishi proposed to Yasaka at the end of 2014 that he wanted to do a small SAR satellite, he said, "I can't do it this way," based on my experience in developing Japanese communication satellites and antennas. I came up with the idea of ​​an antenna method that is light and has a large deployment structure. From there, the idea of ​​Yasaka was realized in a short period of time through trial and error between young people and manufacturing cooperation companies in the Kyushu region.

--What made you want to enter the field of small SAR satellites?

Onishi: Around 2014, after joining the QPS Research Institute, I wondered what fields of earth observation satellites have a predecessor. When divided into four categories: optics, SAR, large size, and small size, I thought that there are already many competitors for large optical satellites and small optical satellites, and even if we enter the market from now on, we will not win. On the other hand, although there are large SAR satellites, the smallest small SAR satellite is TecSAR (Israel), which weighs about 300 kg. I chose it because it is a field where 100 kg or less has not been realized yet and there are no solid players.

Ichiki: One of the purposes of establishing the QPS Research Institute was to establish the space industry in Kyushu. Although Kyushu has good infrastructure such as Tanegashima and Uchinoura, which are launch sites, there is no space industry, so students and engineers who have studied space in Kyushu go out of Kyushu. Then, the founding members who wanted to pass on the knowledge of small satellites researched at Kyushu University to local companies and foster the space industry went around Kyushu and called out to more than 200 companies and aspired. We have grown about 20 local companies that have sympathized with us over 10 years.

Onishi: I would like students and engineers who have left Kyushu to come back to Kyushu and liven up the space industry together. I think that you will be attracted to satellites in new fields with few rivals.

* This article was published on the space business information portal site "S-NET" Standard-bearers of Space Business that Creates the Future SPECIAL / Special Article "".