Earth Observation/Remote Sensing Satellites
Ground facilities support space infrastructure by controlling spacecraft or processing the data that satellites gather and send to Earth. Remote sensing satellites orbit the Earth, gathering data that then needs to be archived, processed, and analyzed while the satellites themselves need to be tasked and targeted to collect imagery in the most efficient manner possible. To perform these tasks, commercial remote sensing satellite operators have established networks of satellite control stations, data reception stations, and data processing centers.
The German Federal Armed Forces operate a ##-satellite LEO fleet called SAR-Lupe, which provides radar imagery with one-meter (3-foot) resolution for surveillance purposes.
Funding is a serious concern for government-supported remote sensing satellite endeavors. Europe’s Global Monitoring for Environment and Security (GMES) program is facing difficulties because of the global economic climate, which is forcing many space programs around the world to cut costs. In November 2011, the European Commission (EC) proposed moving funding for operating the GMES space segment from the 27-member commission to the individual EU member states.
Two major players in satellite-based Earth imagery are U.S. companies DigitalGlobe and GeoEye. Both companies provide imagery to widely used applications such as Google Earth. In August 2010, the U.S. National Geospatial-Intelligence Agency (NGA) awarded 10-year contracts to the companies, valued at $## billion for GeoEye and $## billion for DigitalGlobe, under the agency’s EnhancedView procurement. The NGA specializes in mapping and imagery intelligence, and played a key role in the raid on Osama bin Laden’s compound in May 2011 by providing satellite imagery, geospatial and targeting analysis, and modeling support to plan the successful mission.
In June 2010, Israel launched the OFEQ-9 reconnaissance satellite which joined ## others already in operation. China’s utilization of space for military purposes is even harder to gauge due to the country’s lack of transparency in its space programs. In 2010, the country launched ## Yaogan satellites with the stated purpose of engaging in scientific experiments, land survey, crop yield assessment, and disaster monitoring. Many space analysts believe that the true mission of these satellites is for reconnaissance or other military purposes.
Concerns about global climate change have led to the use of remote sensing satellites to measure the potential impact of humans on the environment. NASA employs more than a dozen Earth science spacecraft measuring a variety of environmental factors, including sea level, the amount of aerosols in the atmosphere, and changes in the size of the Earth’s ice sheets. The United States and Taiwan have partnered to develop the six-satellite FORMOSAT fleet, used to collect atmospheric data for weather prediction and for ionosphere, climate, and gravity research.
Two major U.S. commercial providers of satellite-based Earth imagery are DigitalGlobe and GeoEye. Both companies provide imagery for widely used applications such as Google Earth. In August 2010, the companies were awarded separate 10-year, $## billion contracts from the U.S. National Geospatial-Intelligence Agency under that agency’s EnhancedView procurement. These contracts make it possible for both companies to finish procurement and launch of new advanced satellites capable of discerning objects on the Earth’s surface as small as 25 centimeters (9.75 inches) in size.
Earth observation satellites require unique ground infrastructure support, as these satellites collect large quantities of specialized data. While many ground stations for other kinds of satellites serve as hubs, simply relaying data between satellites and terrestrial users, Earth observation ground stations sometimes require specialized facilities to stitch together and interpret the data collected by remote sensing satellites. This enables people to make use of the imagery in a wide range of consumer and scientific applications.