Rapid Access Imagery
Written by Kevin P. Corbley
GIF 2009 Volume: 7 Issue: 5 (October)
And Derived Products More Efficiently To
Commanders In The Field Or Wherever
Geospatial Information Is Most Needed.
While purchases by the Pentagon have been a boon to commercial satellite operators, these firms face the added challenge of staying ahead of the evolving needs of military end-users. In recent years, this has meant supporting the Department of Defense in finding new ways to deliver imagery and derived products more efficiently to commanders in the field or wherever the geospatial information is needed the most.
“Without a doubt, the dominant trend in this market today is faster, easier and more efficient delivery of geospatial information,” said Nicolas Stussi, director of services and business development for Spot Image Corp., a solely owned subsidiary of Spot Image S.A. and part of the EADS Astrium Services group, which has invested considerable resources to enhance nearly every aspect of its satellite tasking, data downlinking, image processing, and product delivery services to shorten the time gap between acquisition and application.
DoD’s commitment to rapid access to commercial imagery is best exemplified by the Eagle Vision (EV) program currently operated by the Air Force. The program includes five self-contained, portable ground receiving stations with built-in data processing capabilities. Designed with folding antennas, each EV system can be transported on short notice to anywhere in the world on C-17 aircraft. EADS/DCS, another unit of the EADS group, is the prime system integrator for all five Eagle Vision systems.
“The concept behind Eagle Vision is to move the system to a hot spot where commercial imagery can be directly received, processed and handed within minutes of collection to the warfighter on the front lines,” said Brian Cutler, Spot Image program manager. “In addition to military operations, the systems are routinely used to support disaster response efforts involving the Department of Homeland Security and civilian emergency agencies.”
Spot Image has been a mainstay data source for EV since its inception in the early 1990s. A few of the most well-publicized deployments of EV were the support to Hurricane Katrina, the 2007 California wildfires, and more recently the floods in the U.S. Midwest in 2008. In each case, the Air Force downloaded imagery from the Spot 4 and 5 satellites on every pass to an EV station, providing daily coverage of the operation areas for dissemination to emergency personnel on the ground.
“Spot 5 has been for many years, and continues to be, the workhorse of Eagle Vision,” said James G. “Snake” Clark, director for ISR innovations and UAS Task Force. “We can rely on entities such as Spot Image to react and deliver imagery on very short notice. This is critical for our operations, and they always answer the call.”
In the past year, Spot Image has significantly upgraded its support of the EV program by customizing two of its commercially available services for the program. The Air Force was among the first clients to contract for the SPOT Online Access service, which provides access to all SPOT data collected by Eagle Vision or purchased by NGA. This online interface allows DoD personnel in any location to search for archived images. If the data has been downlinked to an EV station, SPOT Online Access directs the user to the appropriate station. Data licensed to NGA is hosted by Spot Image and can be accessed immediately online by military users.
“We keep track of the data purchased by DoD to prevent the various military commands from spending money to buy the same data again, but more important, to provide an immediate access to existing licensed imagery,” said Cutler. “This allows customers to jump-start a project and narrow down their data requirements more efficiently.”
Spot Image has also leveraged its position as a Google Earth Enterprise Partner to develop a viewing portal for the EV program office. The EV Portal provides a real-time feed in a 2-D and 3-D Google Map/Earthbased environment to track the Spot data being received at each of the five EV stations around the world. Personnel in the program office rely on the portal to keep track of what has been collected and what is scheduled for acquisition. It also lets commanders know if collections have been missed due to adverse weather conditions. Customers of specific EV stations can log into the portal for instant updates on acquisitions at their station.
PORTABLE GOOGLE EARTH
The defense/intelligence community has embraced the Google Earth environment as one in which geospatial users with little or no formal training are comfortable viewing and accessing geographic information. The Google Earth Enterprise product enables customers such as NGA to build Web-accessible Google Earth Globes populated with their own data sets. In the military setting, this allows commanders to drill down through multiple levels of satellite and aerial imagery, as well as vector and video data, to gain 2-D or 3-D insights into nearly any area of interest on Earth.
Google and Spot Image teamed in 2008 to develop a portable and deployable version of Google Earth Globe for warfighters to take imagery with them on laptop computers or external drives where no Internet is available. Google Earth Enterprise Portable offers all of the same viewing and processing features as the larger product, but it is designed for use with smaller slices of the Globe, such as a single country or geographic region.
“The main advantage is that you now have imagery in the field in a completely disconnected version of the same, easy-touse, Google Earth,” said Sean Wohltman, a Google geospatial engineer.
With hard-drive space always an issue in mobile computing, Google looked for a medium- to high-resolution image product to serve as the base map for the portable Globe, recommending to customers the SPOTMaps line of products. These are fully orthorectified and color-balanced mosaics of recent 2.5-meter, natural color Spot imagery prepared as COTS products for specific countries and regions around the world. The mosaics are produced by Spot Image and delivered in the fusion-ready format compatible with the Google Earth environment.
Wohltman said the SPOTMaps products are the perfect base maps for the mobile application because the file sizes are relatively small for the amount of detail they contain, and Spot Image has already produced mosaics for many parts of the world. Availability of these mosaics in Google Earth formats eliminates weeks of processing and color-balancing for end-users who might otherwise try to create their own mosaics from individual scenes from other satellites, Wohltman added.
OCEAN MONITORING
DoD’s drive for faster access to commercial imagery and derived information has changed slightly with the creation of DHS. Today, defense/intelligence officials are just as concerned with delivering timely geospatial information to warfighters as to firefighters. As Eagle Vision deployments have demonstrated, imagery in the hands of civilian officials can yield tremendous benefits in responding to and preventing disasters.
The Center for Southeastern Tropical Advanced Remote Sensing (CSTARS) at the University of Miami has been assigned the lead role by DHS to develop operational capabilities that will improve maritime security. One of 43 ground stations worldwide licensed for direct reception of imagery from the Spot satellites, CSTARS has launched a DHS project to monitor vessels as they approach major shipping ports around the country. The process is being tested and used now over various U.S. harbors, including New York Harbor.
“Our multi-tiered system uses satellites, both optical and synthetic aperture radar [SAR], for ship detection and situational awareness to track vessels far away from the ports. Spot Image is supporting us for such operations with both Spot and 2-meter FORMOSAT-2 imagery,” said Hans Graber, professor and chair of applied marine physics and co-director of CSTARS. “We rely on Spot Image’s ability to acquire and provide near real-time imagery over these harbors, allowing us to enhance operational readiness through situational awareness over the entire vicinity of each port.”
Tracking a ship’s movements by satellite is handed off to existing coastal radar installations as the vessel approaches the shore, Graber explained. Once in the harbor, networks of visual and acoustic sensors monitor the ship until it reaches the proper dock. Because the monitoring must continue around the clock, CSTARS is relying on a combination of Spot and FORMOSAT-2 satellite imagery for daytime observations and SAR aboard several other satellites to capture image data at night or in poor weather conditions.
As an official Spot receiving station, CSTARS captures imagery from Spot 4 and 5, as well as from the Taiwanese FORMOSAT- 2 satellite, for which Spot Image has North American distribution rights. Working together, these three satellites provide daily optical coverage over large areas of the Atlantic Ocean, Caribbean Sea and Gulf of Mexico at a resolution sufficient to detect and differentiate ships.
“We want to be able to categorize vessels by their type, such as tankers, cargo ships and container ships,” said Graber, adding that differentiation of ships, especially smaller vessels, will become more exact next year after Spot Image launches Pleiades 1, the first of its sub-meter imaging satellites.
Spot Image moved one step further with CSTARS this year by delivering a turnkey decision support solution, allowing CSTARS to combine imagery and geospatial information (near real-time ship tracking information and video feeds) into one unique, secured, visualization platform. This environment, based on the Google Earth Enterprise solution, allows users to visualize complex sets of geospatial information in one easy-to-use application.
CSTARS’ location in Miami puts it in an ideal position to assist U.S. Southern Command in a variety of maritime and terrestrial applications, and its ground station has played critical roles in delivering timely Spot imagery to military and other responders during natural disasters in the Gulf region, most notably Hurricane Katrina. Graber also sees an expanding interest in the facility’s remote sensing capabilities by the U.S. military, especially its ability to use optical and SAR satellite imagery in complementary roles within a given application.
NEW SATELLITES
Spot Image is using recent technological advancements as cornerstones in the development of services from four new satellites—Pleiades 1 and 2, and Spot 6 and 7—slated for launch over the next four years, starting with Pleiades 1 next fall, which will provide access to 50-centimeter imagery.
“We are committed to this market and the future of Spot Image. To continue the Spot Image legacy as the leader in the medium- and high-resolution imagery market, a constellation of two new Spot satellites, Spot 6 and 7, is scheduled to launch in 2012,” noted Stussi. “And, beginning next year, a constellation of two new sub-meter satellites, Pleiades 1 and Pleiades 2, will place Spot Image in the very high-resolution market segment.”
Pleiades 1 is scheduled for launch in fall 2010 followed by its twin, Pleaides 2, nine to 15 months later. Both platforms will deliver standard natural color, 50-centimeter orthorectified products, with a geolocalization of 3 meters without ground control points.
The Pleiades system has been designed from the ground up to accommodate the needs of very high-resolution imagery customers whose applications require acquisition on short notice of either large regions or small features. The ground segment will allow any Spot Image client to place a tasking request hours before a desired acquisition. This will be made possible by a standard tasking cycle of eight hours, rather than the current 24-hour cycle.
Also, clients with special access requirements will be able to contract for direct tasking privileges. It will enable them to program the satellite to image an area up to 40 minutes before Pleiades passes over the area of interest, giving them exceptional reactivity in case of last-minute emergency or meteorological change.
The Pleiades satellites will be highly agile, capable of pitching and rolling forward and backward and side-to-side up to 45 degrees. This means that by pointing offnadir, one Pleiades satellite will collect up to 5,000 square kilometers per minute of separate or contiguous point targets in one pass. Each will also have a “strip mapping” mode in which multiple 20-kilometer-wide swaths totaling up to 21,000 contiguous square kilometers are captured in a single overpass. Single-pass stereo and tri-stereo imaging will be available, as well as coastal/ border-long acquisitions.
Working in tandem, the two satellites will acquire approximately 1 million square kilometers per day of very high-resolution imagery with a daily revisit cycle.
“With the increasing amount of commercial satellite imagery available to users, we know that we will make our difference with Pleiades on the services and solutions we will offer to our customers. Having such high-quality, high-resolution imagery inhand is great. Offering the right services to our users so they can be more efficient and more relevant is clearly essential. That’s our main focus,” said Stussi.
With Pleiades nearing the launch pad, the development of Spot 6 and 7 has begun to secure availability of 2-meter imagery up to 2023 and to complement the very highresolution data from the Pleiades constellation for an optimal combination of global coverage and local resolution. These satellites will have the same 60-kilometer swath as the existing Spot satellites with the enhancement of 2-meter panchromatic and 8-meter multispectral spatial resolution. The multispectral bands will be blue, green, red and near-infrared. Other enhancements include an increased reactive tasking capacity and a huge acquisition capacity of 2.5 million square kilometers per day.
“Of critical importance to our DoD clients is our ability to generate highly accurate digital elevation models, known as Reference3D DTED Level 2 products,” said Drew Hopwood, Spot Image project manager. “All four of the new satellites will collect stereo-image and tri-stereo data that can be used to generate DEM products, and we expect even greater precision and accuracy thanks to design advancements in the satellites themselves.”
Reference3D is Spot Image’s premier product developed from the high-resolution stereoscopy sensor first introduced on Spot 5. Reference3D combines a digital elevation model (DTED Level 2), a 5-meter orthorectified image and eight quality masks to provide users with a complete geospatial base product. Reference3D has been utilized by many defense/intelligence agencies to fill in data gaps in the shuttle radar topography mission global elevation data set, which sought to map surface elevations for the entire Earth.
Spot 5 has collected 120 million square kilometers of cloud-free stereo pairs ready for processing into Reference3D products, making it possible for Spot Image to generate products in a matter of days for areas already imaged. In addition, over 35 million square kilometers of off-the-shelf DEMs (DTED Level 2) are ready for delivery. These products are used by DoD clients for orthorectification of other image data sets and for accurate terrain representation in visualization and simulation environments.
“One new satellite launch each year for the next four years guarantees continuity of services until 2023 for medium-, high- and very high-resolution satellite imagery,” said Stussi. ♦
Kevin Corbley is a communications consultant specializing in the geospatial industry. He may be reached at www.corbleycommunications.com.