JAXA Japan Aerospace Exploration Agency

Q. Tell us about the work you do.

Monitoring of industrial-waste processing sites by DAICHI. The chronological imagery shows the accumulation of waste. (courtesy: JAXA/ Yokoyama Geo-Spatial Information Laboratory Co., Ltd.)

For many years, I’ve been conducting research on remote sensing for practical uses. After I was appointed at Iwate University in the late 1970s, I made environmental observations of things such as forest vegetation and sea surface temperatures by using aerial remote sensing data. In those days we had pollution all over Japan and a lot of debate over environmental issues. But we didn’t yet have any Earth observation satellite data, or computers to process a large volume of data.

When we got to the 1980s, we were able to use data from LANDSAT, an American Earth observation satellite, and computers became more advanced. So for the first time we were able to do full-scale research on Earth observation satellite data in Japan. We also worked on validating the accuracy of ocean and land observation data, and refining the processing and analysis of the data. After I retired and became a special-project professor, I was involved in projects such as the one in which local communities used observational imagery from DAICHI, the Advanced Land Observing Satellite, with support from JAXA. In 2011 I started a private-sector company that performs analysis and processing of satellite data, and digital elevation model.

Q. How exactly do local communities use satellite data?

Of course they use DAICHI’s imagery when there’s a natural disaster, but even in the absence of disasters, I think satellite data needs to be used more for local purposes.

For example, one of the initiatives I proposed was to use satellite imagery to monitor the illegal dumping of industrial waste. In 1999, illegal dumping in Iwate and Aomori prefectures put around 800,000 cubic meters of industrial waste into the environment. Iwate had made enormous efforts to restore the environment to its original state, so it had long been trying to monitor illegal dumping of industrial waste. Iwate, which has the largest land mass of all of Japan’s prefectures, is about 80% tree-covered, mountainous terrain. The time it took to find and expose illegal dumping of industrial waste with security staff and helicopters alone became a problem. In comparison, a satellite can monitor a wide area all at once, so I thought this could be a good use of the technology.

In 2007, we started on a project commissioned by Iwate Prefecture to build an industrial-waste monitoring system using DAICHI imagery. We would get tips from on-the-ground monitors about locations of illegal dump sites, and see if we could spot the sites using data from DAICHI. Satellite images with accurate observation dates make for definitive proof, so this was quite effective. Satellite observations also proved to be a good deterrent. The Ministry of the Environment recognized our project’s achievements, and in 2009 and 2010, fourteen municipalities across Japan began industrial-waste monitoring trials based on the Iwate formula. Unfortunately, we had no choice but to cancel the program when DAICHI ceased operating in May 2011, but I think this gave us the chance to discover new potential local uses for satellites.

Q. What action did you take when the Great East Japan Earthquake struck last year?

The area around Rikuzentakada city, Iwate prefecture before (upper image) and after (lower image) the Great East Japan Earthquake, as observed by DAICHI. The yellow circle shows where a pine grove that stretched for 2 km east to west was completely washed away by the tsunami. (courtesy: JAXA/ Yokoyama Geo-Spatial Information Laboratory Co., Ltd.)

Immediately after the earthquake, we consulted with JAXA and quickly started processing and analyzing DAICHI satellite imagery to get an understanding of the damage on the coast of Iwate, Miyagi and Fukushima prefectures, where the tsunami damage was greatest. We then made 1/30,000 scale images of the entire coastline available to the prefectures’ emergency response headquarters, municipalities, the Self-Defense Forces and the national government’s local agencies. Although the image of the Iwate coastline alone was seven meters long, I personally delivered it to the agencies that needed it. That was on March 16, five days after the quake. It took about three weeks for the Geospatial Information Authority to start releasing new aerial photographs, so these pre-quake DAICHI images were all we had.

Keep in mind, some of the images we provided were from before the disaster. Since I had already started applying DAICHI satellite imagery for local uses, we had these images available as well.

Q. How exactly were the images you provided put to use?

The pre- and post-quake images we provided were put up at the prefectural office and the military’s emergency response headquarters. All across the damaged area, many buildings were destroyed by the tsunami; electricity, telecommunications networks and transportation links were cut off; and cars couldn’t move because of gasoline shortages. It was extremely challenging trying to understand the nature of the damage and to send aid to remote places such as the tips of peninsulas and islands. Under these trying circumstances, the DAICHI images helped enormously in allowing us to understand the nature of the damage across the whole area we had to cover.

Q. Did you already have connections with municipalities before you started sending them images?

Yamada Bay, Iwate prefecture before the earthquake, as observed by DAICHI. (Photo taken on September 10, 2006.) (courtesy: JAXA/ Yokoyama Geo-Spatial Information Laboratory Co., Ltd.)


Yamada Bay, Iwate prefecture, photographed in December 2012. New cultivation rafts are visible. (courtesy: Ryuzo Yokoyama)

We’d done a lot of work for local officials in the Tohoku District through our local application projects with DAICHI imagery, so I had a network. My intent was to popularize the use of satellite data through joint research and other work with them. Because of these relationships, I had local officials coming directly to me and asking, “Do you have any satellite images?”

For example, one of them was the municipal government in Yamada-cho, in Iwate. A few months after the tsunami, they requested a pre-quake DAICHI image of Yamada Bay. They cultivate a lot of seafood – oysters, scallops and wakame seaweed – and they had 4,000 cultivation rafts in Yamada Bay. All these rafts were washed away by the tsunami. If they couldn’t restart the cultivation, then all the people in the fishing industry would lose their incomes. So based on the pre-disaster images, which showed the position of the rafts, they were able to restore Yamada Bay. Now, a year after the earthquake, they’ve brought back around 70% of the rafts.

Q. What problems do you think need to be solved regarding the use of satellites in disaster response?

A crucial part of effective disaster response is getting information out quickly and making sure it gets to the people who need it. That’s why it’s important in normal times to partner with local communities and build a network. In the town of Yamada-cho, which I was just talking about, some people had the foresight to make good use of satellite data, but there certainly weren’t many others who did. I feel that we still need to do more to popularize the use of satellite data by local communities.

Q. In what ways do you hope satellite data will be used?

Every day people see images from Himawari, the weather satellite, during the weather forecast on TV. The average viewer sees the image and thinks something like, “I guess I should bring an umbrella today because it’s cloudy and it might rain.” The image lets us imagine approximately what the weather will be like. These images from Himawari are now firmly rooted in our daily lives.

I’d like to popularize images from Earth observation satellites such as DAICHI, so that they are used on a frequent, daily basis, like images from Himawari. I imagine people in sectors such as agriculture, forestry and fishing studying Earth observation satellite imagery as they would a weather map, getting information that helps them with their work. But to do that we need effective techniques for using these images.

Q. What are your expectations or hopes regarding JAXA?

I think that DAICHI was the first satellite to provide information that was useful on a local basis. DAICHI ceased operating in May of last year, and now we are developing its successor, ALOS-2, which will also be equipped with synthetic aperture radar. ALOS-3, which will have optical sensors, is still in the planning stage, but images taken with optical sensors will be easier for the average person to make sense of than radar images, so I think it would be very effective if we could popularize its use. That’s why I want ALOS-3 to be launched soon, too. I expect that DAICHI’s successors will spread the local use of satellite data more and more.