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Worldwide Imagery
Written by Tom Marlowe
International firms are stepping forward as
major potential players in satellite imaging
and a source of innovative new technologies.
In addition to the huge amount of business they do with the major U.S.- based commercial satellite imagery providers, GeoEye and DigitalGlobe, officials of the National Geospatial-Intelligence Agency have indicated an interest in working with other companies around the world.
As Lloyd Rowland, NGA deputy director, put it in a recent interview, “We’re also looking at using commercial sources from other countries, which are becoming more available and accessible to us. We continue to assess the quality of these sources to meet our diverse customer needs. In the future, new collection systems, foreign and domestic, will be important to us and mission accomplishment. NGA anticipates increased use of these sources to augment our national assets, particularly in the next five to seven years.” (See MGT 7.2 April 2009, page 21.)
To cite just one example of the potential benefits, defense agencies worldwide are poised to take advantage of advancements in satellite imaging technology and to take a cue from agriculture interests in using imagery for change detection over time.
As far back as 1998, the United Nations voiced interest in a daily repeat imaging capability all around the globe in order to detect emergencies so that UN members could respond to them, recalled Paul Stephens, director of sales and marketing for DMC International Imaging.
U.K.-based Surrey Satellites Technology Ltd. (SST) responded to the need and designed a satellite constellation to provide daily repeat imaging anywhere in the world. The constellation consists of four satellites, each carrying a 32-meter resolution multispectral imager. The satellites achieve daily visits by setting the imagers to a 650-kilometer field of view.
“So with four satellites in a sunsynchronous orbit as they go from pole to pole, each one comes up a few minutes after the other,” Stephens said. “By that time, the world has turned around 650 km so the next one is imaging alongside the previous track.”
SST incorporated the Disaster Monitoring Constellation under its own company—DMC International Imaging (DMCII)—to manage the requests of consortium partners and to coordinate the constellation for joint activities, part of its international charter for space and major disasters.
The constellation’s satellites are very small— about one-foot cube. Easily and rapidly produced, they were launched between 2002 and 2004. Each is owned by a different government or commercial organization, but they operate under an agreement to monitor the world for disaster response. DMCII therefore works alongside major space agencies to provide additional satellite resources.
“So just last week, our emergency on-call officer was on duty for 24 hours a day, seven days a week, providing coordination for the entire charter satellite fleet, including the U.S., Canada, Europe, Japan, India, China and Argentina,” Stephens remarked.
DAILY REPEAT IMAGING
The company sells imaging services with a daily repeat capability. It provides services for precision agriculture and forestry monitoring and for anything that is changing rapidly that needs to be monitored in a short time period.
DMCII services some very wide area coverages—imaging 27 countries in Europe for the European Commission, plus another 11 around the perimeter. DMCII was the first company to achieve that imaging within a one-month window for each country. Its services are under contract by agricultural and geological agencies such as the U.S. Department of Agriculture and the U.S. Geological Survey (USGS).
DMCII’s ability to monitor changes in agriculture over time also has led it into a contract with the U.K. government to monitor Afghanistan. The overall campaign involves different companies and different sensors, but its goal is to monitor changes in opium production as well as wheat production.
At press time, DMCII was planning to launch the next generation of its satellites this spring or summer, with two new satellites that have 22-meter resolution.
“Working together, these first two and a third one to launch later in the year will provide the ability to monitor the entire global surface, probably eight times per year,” Stephens said. NGA is considering the use of rapid repeat capability for change detection as well. The agency could hire the services of DMCII through its USGS contract.
HIGH RESOLUTION, HIGH SPEED
New satellite constellations have been able to deliver imagery even faster. In February, Germany-based RapidEye launched its satellites to provide world governments the opportunity to visit every point on Earth at least once a day with satellite imagery, according to RapidEye Chief Executive Officer Wolfgang Biedermann.
RapidEye operates a constellation of five satellites, which are multispectral with a ground resolution of 6.5 meters.
“The advantages of the constellation are that we can do large area coverage at reasonable ground resolution, and we have the capability of revisiting every point on Earth once a day,” Biedermann declared. “We obviously have to make a choice of what we eventually want to image, but we can choose between the whole land mass of the Earth, which means we have the best chance of anybody to get images as quickly as possible since we will have a satellite ready whenever the weather is good.”
This capability sets it apart from other commercial image providers with fewer satellites. If a company has only one or two satellites, it usually has a revisit time of once a week or once every two weeks. On that seventh or 14th day, the company would need to have a sunny day or else miss its opportunity to get an image if it is using optical sensors.
RapidEye stood up this capability to observe agricultural patterns. Within six months, RapidEye satellites record the entire life cycle of a vegetation period, with a goal of providing one coverage per month during the period to provide information for crop determination, vegetation monitoring, growth monitoring, damage assessment and associated tasks, Biedermann said.
“We have very good opportunities to conduct frequent change detection to uncover changes that are happening in the world and to monitor areas regularly and see what is happening in certain areas, especially those that are difficult to reach or go to in any other mode than by remote sensing,” Biedermann remarked.
So RapidEye works with agricultural clients such as agroinsurance companies in Europe and in North America, and provides information services to farmers through agriculture cooperatives.
The company is moving into other fields, however, recently monitoring pipelines in Brazil for a large oil company and beginning discussions with military agencies on large area coverage for change detection.
“In the military field, we do not have a firm commitment yet from any customers. We have only been operating since February of this year and our data is in the qualification process,” Biedermann noted.
Regardless of the customer, RapidEye prefers to provide customized solutions. Clients can purchase rectified geo-referenced data or raw data. RapidEye addresses the specific needs of its customers specifically, eschewing off-the-shelf information services.
GROUND CONTROL
RapidEye’s revolutionary capabilities are available from satellites built under the direction of the Canada-based MDA Corp., which served as the prime contractor for standing up the constellation. MDA’s U.S. subsidiary, MDA Federal, provides geospatial services to U.S. defense and intelligence agencies also, said David Hargreaves, a vice president of MDA Information Systems.
Hargreaves heads up MDA’s systems engineering and integration efforts, which include building satellite ground systems for imaging satellites and building command and control systems. He also leads MDA geospatial services, which sell space-based data and information derived from space-based data.
But MDA remains well known for the construction of satellites such as the RapidEye constellation.
“We held the prime contract for the company RapidEye,” Hargreaves said. “In that role, we did all of the top-level system design. We subcontracted out the parts of the spacecraft and we then integrated the spacecraft. We managed the launch. We built the ground system. We deliver a full on-orbit mission to the company RapidEye. In addition to that we have a long-term operations and maintenance support contract with them to help them.”
MDA also supports RapidEye in the worldwide ground station market and reselling and exploiting its data around the world.
Where ground stations are concerned, many defense agency and industry customers prefer to have their own ground stations for direct receipt of satellite data, Hargreaves said.
Because RapidEye satellites have unmatched resolution, they are extremely useful for change detection, he added. MDA provides a lot of added value in that area in particular.
“We already do change detection for a lot of our customers. But the idea for a lot of military users is to use RapidEye as a wide-area surveillance capability, which really triggers things that are interesting to them that can then be looked at with other higher resolution assets,” Hargreaves commented.
“The broad concept of operations that a lot of our customers are interested in is having the RapidEye on a continuous wide area surveillance basis with some very sophisticated change detection software and systems that we build to identify things that are happening that should be of interest or should be followed up. The idea generally with most customers is to task other assets like WorldView or those types of high-resolution satellites or potentially things like airborne aircraft or other assets to take a more detailed look at what is going on,” he said.
So for example, the companies have worked together to monitor Iran and the growth of its nuclear capabilities.
“We are able to offer to our intelligence customers the whole gamut of multisatellite intelligence solutions that allows them to do more sophisticated operational concepts where you are using one satellite to cue another satellite and those kinds of things. It’s a broader solution than just a RapidEye ground station, for example,” Hargreaves said.
GEO-INFORMATION SERVICES
In 2001, Infoterra GmbH answered the call of the German space agency to commercialize remote sensing services. The company came up with a business plan to sell not only imagery but information on the Earth—geo-information. To fulfill its goals, Infoterra designed a satellite that it operates jointly with DLR, the German space agency. The satellite, TerraSAR-X, has been operational since January 2008.
“As a geo-information service provider, we are working in areas such as traditional topographic mapping, including defense mapping. We also start providing environmental control services in particular for environmental agencies across Europe including the European Environmental Agency of the European Commission,” said Infoterra Managing Director Joerg Herrmann.
This year, Infoterra will expand the TerraSAR-X program by launching a twin satellite, which will fly in formation and provide more detailed information in radar measurements. As a result, the pair of satellites will provide a global digital elevation model at level 3, which corresponds to an elevation model point posting of 10 meters with a height accuracy of 2 meters or better.
Infoterra’s clients include civil and defense mapping authorities, European Union environmental agencies, environmental security interests, and emergency response organizations.
“In the commercial environment, customers are operating in the exploration of oil and gas and minerals environment. Those include the big players acting globally. That relates to the fact that, with our radar systems, we are in a position to very precisely measure changes on the surface and also to measure subsidence and uplift effects, which typically occur in the context of oil and gas production,” Herrmann commented.
Some clients of the TerraSAR-X program receive their imagery through direct reception stations. One such station is under test operations with the U.S. Air Force under the Foreign Comparative Testing Program. NGA has evaluated the Infoterra data services and qualified them.
“The most differentiating aspect of our radar system is that we have very precise pixel location accuracy, which can be as good as half a meter,” Herrmann noted.
Infoterra soon plans to complete installation of near realtime services for monitoring through employment of a polar station, which will capture imagery from the satellites on every orbit. This saves traveling time, thereby drastically reducing the age of the imagery.
The company also is working on the establishment of a stereoscopic radar processing approach called radargrammetry, which enables the production of pixel elevation models from a stereo pair of images.
“In contrast to electo-optical imagery, radar is a bit more complex to deal with, so one of the areas that we are working on also with international partners is to come up with higher level products rather than pure imagery and to equip our customers with complete solutions rather than just sending imagery to them,” Hermann concluded. “To date, significant training is required to aid the customers to work efficiently with the radar imagery because the physics of radar is different than those of electro-optical.” ♦