Earth Observation/Remote Sensing Satellites
The majority of Earth observation satellites launched in 2016 were ##. Only ## of the ## Earth observation satellites had a launch mass of ### kilograms (### pounds) or more. The number of Earth observation satellites with a mass between ## and ## kilograms (##–## pounds) launched in 2016 was ##. Together, the Earth…
From Sidebar — “Satellite imagery sales were helped along by increasing tensions in Afghanistan and then Iraq. In time, foreign purchases and major contracts for data (ClearView and NextView) from the U.S. National Geospatial-Intelligence Agency (NGA) brought growth and a measure of stability to the data market. The acquisition of Space Imaging by ORBIMAGE [now known as GeoEye] has also further stabilized the industry.”
The DoD and national security agencies could also use a variety of Earth observation satellites, like Space Based Infrared System (SBIRS) under development, Fast On-orbit Recording of Transient Events (FORTÉ), and the Multispectral Thermal Imager (MTI) that provide intelligence through a variety of sensors, including multi-spectral imagery, thermal images and event classification, radio burst detectors, and radar imaging.
AGI designates remote sensing satellites as surveillance/military satellites. Exhibit 3p (below) provides the number of these satellites by country. AGI reports ## active U.S. surveillance/military satellites that it designates as having “unavailable” orbital parameters. In addition, the line between some remote sensing and Earth science satellite classifications is not always clear-cut.
Remote sensing satellites provide images of the Earth for civil, scientific, military, and intelligence applications using a number of different technologies.
Many remote sensing satellites have dual military and civil or commercial purposes. India launched its indigenously developed radar imaging satellite, RISAT-1, in April 2012. The satellite will join RISAT-2 and will provide India with the ability to image features on the ground even if covered by clouds or foliage due to its use of a C-band microwave synthetic aperture radar. RISAT-2, a radar-based reconnaissance satellite, was purchased from Israel and deployed before RISAT-1 to help track and prevent terrorist activity, such as the 2008 Mumbai terrorist attacks.
Weather satellites form another major segment of remote sensing satellites, typically operating in GEO or polar LEO orbits. These systems are primarily operated by national governments for forecasting near-term weather patterns. Delays and funding issues could endanger the robustness of some weather satellites programs, as several existing polar satellites are operating near or beyond their design life and are in need of replacement. One program in particular, the Joint Polar Satellite System (JPSS), is set to replace the aging Polar-orbiting Operational Environmental Satellite (POES) fleet.
Land imaging satellite performance is described using a variety of characteristics, including differences in spatial resolution (as measured by how many pixels compose an object), positional accuracies (as measured by the extent to which objects are represented accurately), and spectral capabilities (as measured by wavelengths of light captured, including visible and beyond-visible spectra). High-resolution land imaging satellites have resolutions below 1 meter (3 feet) per pixel, allowing users to distinguish cars from trucks, for example.
Military-specific observation satellites can be used for reconnaissance or other intelligence-gathering purposes. The capabilities of remote sensing satellites can sometimes obscure whether or not they are being used for civilian or military applications.
Weather satellites are a major segment of remote sensing satellites. Most weather satellites are in GEO or polar LEO orbits and have traditionally been operated by national governments for near-term weather forecasting. However, austere government budgets have caused weather-focused agencies to struggle to sustain existing programs under reduced funding. Maintaining existing programs with old, albeit reliable, data acquisition capabilities potentially inhibits the development and introduction of new, higher quality instrumentation that could increase accuracy.